There are four main types of winter squash, and some hybrid crosses. Refer back to your catalogs or websites if you are unsure which type your varieties belong to, as this helps determine when to harvest. If you haven;t grown any winter squash this year, use these photos and descriptions to help you plan for next year. Most of our photos are from Southern Exposure Seed Exchange. We tend to get caught up in the excitement of harvest, and forget to take photos!
Leave the squash on the vine until fully mature. Once the vine is dead, the squash can’t get bigger, but can ripen, change color and convert starches to sugars, (tasting better). In general, squash are fully mature and storable when the skin cannot be pierced by fingernails, but testing each one would leave ugly scars and reduce shelf life, so learn the other signs of ripeness. Yield could be 3¼ lbs per row foot (about 5 kg per meter.)
Not all the squash on one plant will be ripe at the same time, but they come to no harm sitting in the field (provided there is neither frost nor groundhogs). We harvest once a week, using pruners. We cut them with fairly long stems, which helps them store best. Those who need to pack squash in crates remove the stems so that they do not injure their neighboring squash. If you do this, you need to cure the open ends before crating. Handle squash as if they were eggs, not footballs. Bruising leads to rot in storage. Look for black rot infestations (concentric circles on butternut) and either compost those, or salvage the good parts for immediate use.
Pepo Squashes are ready soonest
The first squash ready to harvest (in early September) are the Pepo “winter” squash species (more properly called fall squash), including acorn squash, delicata, dumplings, spaghetti squash, and most orange pumpkins. If you want to start harvesting these in August next year, sow earlier than late May! Pepo squash are fast maturing, short-storing, mild flavored. They have prickly leaves and stems. They are susceptible to vine borers, and perhaps a little more susceptible to viruses than other types. Pepos have hard, five sided stems, and the fruits are often ribbed.
When they are ripe, the “ground-spot” of Pepos usually becomes the color of pumpkin pie filling after the cinnamon is stirred in, or else bright orange. The stem will still be bright green. Wait till at least 45 days after pollination. Harvesting too early will disappoint: the squash will be watery and fibrous, without sweetness. Pepos can store up to 4 months, so check them every week and eat them up before New Year.
Maxima squash plants have huge hairy leaves. Fruits have thick round stems, different from the angular stems of the other species. This group includes buttercups/kabochas, hubbards, bananas, the Big Max giant pumpkin, Jarrahdale, Candy Roaster, Galeux d’Eysines and Rouge Vif d’Etampes. They are very susceptible to wilts, borers and squash bug damage. We have found Jarrahdale to have relatively high resistance to squash bugs compared to other Maximas. The hybrid Kabocha, Cha-Cha, is reliable. Kabocha may be harvested slightly under-ripe, as they continue to mature after harvest.
Maxima squash are ripe when at least 75% of the stem looks dry and corky (tan, pocked, wrinkled). They have fine-textured good-flavored flesh They will store 3-5 months, sometimes longer.
The weakness of maxima compared to the others is susceptibility to downy mildew. There may be other fungal pathogens that maxima is more susceptible to.
In central Virginia, maximas are almost always a loss, due to squash vine borers. Ken Bezilla at Southern Exposure Seed Exchange has watched the plants live for about 70-80 days, the fruits get nice and big and then the plants die all of a sudden. The safest way to grow them is under rowcover or netting, and keep them covered for the first 60 days (briefly uncovering for weeding and pollination).
Moschata squash plants have large hairy leaves, and fruits have flared angular stems. This species is the most trouble-free, with no damage from borers and cucumber beetles. The tougher stems repel invaders. They need warm growing temperatures above 60°F (16°C). Butternuts and similar tan-colored squash, such as Seminole, Cheese, and the large Tahitian Butternut and Lunga di Napoli are in this group.
The Moschata species usually have bright orange, sweet, tasty flesh. These squash are ready when the skin is an even tan peanut-butter color, with no pale streaks or blotches. Many have green lines radiating down the squash from the edges of the stem. In some varieties, these green lines disappear when the squash is ripe, but not in all kinds. If in doubt, cook one and see. Or try a slice raw. These squash also have angular stems, but unlike the stems of pepo squashes, moschata stems flare out where they join the fruit. Moschatas can store 4-8 months or even longer. Seminole is a Moschata that will keep on the shelf for a whole year after harvest. It has a hard shell!
Mixta (Agyrosperma) Squash
The fourth species, Argyrosperma, or Mixta, includes many old-time varieties from the south. Flesh is often yellow rather than orange, and these squash are often cooked with sweeteners. Plants are rampant; leaves are large and hairy. Fruit stems are slightly flared, slightly angular, and hairy. This group has the best drought-resistance and also good resistance to borers and beetles. Cushaws are Mixta species. They are not all great storers.
Curing and Storing
Butternut and buttercup squash need to be cured at 80-85°F (27-29°C) for 7-10 days to be sweet tasting. Other varieties do not need to be cured, unless the stems have been removed, You can cure squash in a greenhouse with 80% shadecloth, or simply in a warm storage room.
Curing conditions for winter squash can be quite far from the ideals. Many people simply put the squash straight into storage Just don’t eat uncured butternut or buttercup squash, ie within two weeks of harvest, to avoid disappointment.
Store winter squash in relatively warm and dry conditions: 50-60°F (10-15°C) and 50-75% humidity. Check through stored squash once a week, removing any that are rotting. Squash have a medium demand for ventilation, similar to carrots, more than potatoes. Temperatures below 50°F (10°C) can cause chilling injury, which reduces shelf life. Do not store squash with potatoes or onions; like most ripe fruit crops, squash exhales ethylene, which increases sprouting in potatoes and onions (and other roots and bulbs).
Here we are with my monthly series of 14 Workhorse Crops (including two pairs). These crops are reliable under a wide range of conditions. My goal with this series is to help you become more efficient, productive and profitable (if selling) as you deal with another strange year. Maybe you are not at home as much as last year, or maybe your helpers have gone back to school, but you deeply appreciate growing your own food. You want less time-consuming crops and growing methods. You can use the search box to find previous month’s entries, such as August.
Workhorse Crops to Plant in September
In September in central Virginia, the heat is less oppressive, especially since Tropical Depression Ida washed by. The day-length is definitely shorter, soon we will be at the equinox with only 12 hours of daylight. Gardening is more focused on harvesting and less on planting. Food processing is at its busiest.
This month we will put our fall and winter garden plan into action. Plants take longer to mature from September onwards, so don’t delay any plantings. Try a few different dates, and keep good records, especially if you’re a new farmer or gardener, and improve your plan for next year.
In September we only have enough good growing conditions to plant 5 of our 14 Workhorse crops in central Virginia. Down from last month’s 8. We can still transplant cabbage, collards and kale, and sow carrots, and chard (or transplant the chard.)
Cabbage and Collards:
September is much too late for us to start cabbage, but we could still transplant early in the month, if we have transplants with four true leaves (3-4 weeks after sowing). If you only have bigger transplants, remove some of the older leaves until four leaves remain. This will help the plants survive by reducing evaporation (transpiration) losses. Collards can be sown here until September 15.
If insect pests are a problem, cover the transplants for four weeks, until they are big enough to survive. Nets are better than rowcover in hot weather, as airflow is better and heating is less. I wrote last month about ProtekNet Insect Exclusion Netting from Dubois Agrinovation.
Another advantage of nets over rowcover is that you can see what’s growing! Back before ProtekNet I found one year that I had been studiously watering a covered bed that was mostly galinsoga! It was quite big, and I had assumed it was greens!
Two weeks after transplanting, till or hoe around the plants. Four weeks after transplanting, remove the netting entirely, and hoe and till again. At that point you could undersow with a mix of clovers to be a long-term cover crop, unless you plan to plant an early spring crop in that bed.
This is actually late for carrots but if you failed to establish them in August, hurry out and sow some early in September. You won’t get big carrots, but you’ll still get carrots! Hoe between the rows as soon as you can see them, because carrots grow slowly and fall weeds grow fast!
Once the carrots are 1” (2.5 cm) tall, hand weed, cultivate with claws (to kill weeds that haven’t even emerged yet) and thin to 1” (2.5 cm) apart. Simply pulling the weeds is not as good as also lightly disturbing the surface of the soil. Heavy rains can cause crusting, which makes it hard for seedlings to grow. Breaking up the crust lets air and water in. I have noticed that crops make a growth spurt after hoeing. If you think you might have carrot rust flies in your area, collect up all the carrot thinnings and take them to the compost pile, so that the pests won’t be attracted by the smell of carrot leaves, and move in to eat your carrots.
Later thin your carrots to 3” (7.5 cm) and weed again. That’s a September task, if you sowed in August. The tiny ones you pull out may be big enough to wash and throw in a salad. Before they develop the orange color they don’t have much flavor, but they are a treat for the eyes anyway!
We grow Vates dwarf Scotch curled kale, the most cold-hardy variety I’ve found. I’ve tried every type of kale I could get my hands on, including some imported from Europe. Vates isn’t huge – we plant 4 rows 10″ (25 cm) apart in each bed. We want 6 beds of kale to over-winter, and there isn’t time to transplant it all. We direct sow, two beds at a time, every 6 days. We water the two newly sown beds, daily as needed, until the seedlings emerge.
Often we get patchy emergence in those hot August days, so we use carefully dug thinnings to fill gaps. Our goal is one plant every foot (30 cm). Our mixed direct-sow/transplant method requires less watering than if direct sown all at once and gives us a solution if we get patchy germination. September 15 is our last sowing date for kale for harvests in late fall and through the winter. We cover the beds with netting, until the plants are large, or the weather gets too cold for pests.
Kale makes some growth whenever the temperature is above about 40°F (5°C), which happens in our winters on many days, making this a valuable winter crop. We will also sow more kale in late January, to give us a spring crop.
Chard: Swiss chard can be sown here in August, and transplanted in September for a good fall harvest, with the option of overwintering under rowcover. It grows small leaves after only 35 days, and full-size leaves after 50 days. Chard is our poster-child insurance crop! So easy! So productive! It is not eaten by bugs, and does not have problems germinating in hot weather like spinach does.
You could direct sow chard in September and protect it for the winter, for a late winter and early spring harvest.
Workhorse Crops to Harvest in September
Eleven of our 14 workhorse crops can be harvested in September (also true in August, but now with one substitution!)
Beans can be harvested until the first frost (or later if we cover the beds with rowcover when a frost threatens). We also cover the bean beds (and squash, cucumbers, zucchini and other tender crops) whenever there is a chilly spell. This keeps the plants warmer and growing faster. Vegetable crops begin to take longer to ripen in September. It’s certainly true that pollinating insects can’t get at the flowers to perform their pollination services and make more beans, etc. But that doesn’t matter. We are more interested in fattening up the already pollinated beans!
Cabbage We eat about 50lbs (25 k) a week. Fall planted cabbage will be ready from September 25. We like Early Jersey Wakefield and Farao for fast-maturing cabbage.
Carrots: We generally hope not to need to sow carrots between June and the beginning of August, because carrots grown in hot weather don’t taste sweet and can even be soapy. If we did not grow enough carrots in the spring, we sow in June, or July and harvest those carrots about 2-3 months later (less time in warm weather, longer as the weather starts to cool in the fall). So, some years we harvest carrots in September.
Chard can be harvested whenever you want some. Snap or cut off some outer leaves and refrigerate them promptly. We use our Leafy Greens Mantra “8 for later” meaning that we make sure to leave at least eight of the inner leaves on each plant, as we harvest the outer leaves. With chard, we can take a couple more than this, but we do want to harvest at sustainable levels.
To overwinter chard in our climate, we cover the bed with rowcover on hoops. We can continue to make harvests into early winter. The mulch and rowcover help keep warmth in the soil, which keeps the crop growing.
Another method of over-wintering chard in reliably cooler climates, is to make a big harvest of all the sizeable leaves, just before the daytime temperatures are around freezing, then pile tree leaves, straw or hay over the bed for the winter. Covering the whole stack with rowcover is even better. Our winter conditions are too variable for this – we get cold spells interspersed with warm spells in almost every month, causing the plants to make some growth among the mulch.
The outdoor killing temperature for unprotected Bright Lights chard is 22°F (–6°C); red chard survives down to 15°F (–9.5°C) and green chard to 10°F (–12°C).
Collards can be lightly harvested in September, if you started them early enough. What’s more likely true for us, is being able to harvest leaves of senposai. No, not the same as collards! But it fills the same spot on the dinner-plate – fresh leafy greens. It’s been a long summer with only chard, this year, as we were short of spring cabbage, and don’t have any fall cabbage or broccoli yet.
Potatoes: We can plant potatoes between mid-March and mid-June, leading to harvests in July-October. It’s as important not to leave potatoes baking in the sun as it is to protect them from frost, both when planting and when harvesting. Read more aboutpotato harvest here.
Our March-planted potatoes are in the root cellar. By mid-September, we need to cool the cellar to 60°F (16°C)
Sweet Corn harvest is still going strong. Sweet corn is ready to harvest about three weeks after the first silks appear. Some growers say you should harvest daily, but we find that 3 days a week is often enough, and gives us a nice amount from our 1050-1325 ft (320-400 m) plantings to feed our community. We sow sweet corn six times, for continuous harvests from early July to mid-October.
Corn is ready when the silks are brown, not before! If they are brown, and the ears are plump and filled to the end with kernels, take a closer look. Mature ears stand away from the stalks. If you are still learning, slit the husks at the side of the ear with your thumb nails and look at the kernels. (Don’t puncture the husks on the topside of the ear as the dew and a million tiny beetles will get in and make a mess.) The kernels should be a bit square and fairly tight-packed, not round and pearly with rounded diamond-shaped spaces between them. An opaque, milky juice will seep out of punctured kernels. If your sample ear wasn’t ready, push the husks closed over the ear and wait a few days.
Be sure to shade your corn after harvest and get it cooled as soon as possible, as the flavor deteriorates if it sits around.
Tomatoes are cranking out their fruit but starting to look “back-endish” – spotty, and smaller. To minimize the spread of fungal diseases, wait for the leaves to dry in the morning, before harvesting. We plant maincrop tomatoes (sown in mid-March) and late tomatoes (sown in mid-May). This way the late ones peak after the maincrop, and keep the plentiful supply going longer. This year our late bed includes a few Black Cherry and Sun Gold cherry tomatoes as well as lots of our standards: Tropic, a heat-tolerant, disease-resistant round red one, and Jubilee, a lovely flavorful orange that is also a feast for the eyes. This year I have been particularly impressed with its healthiness – the fruits are reliably unblemished and do not readily split. Truly a workhorse variety!
Watermelon harvest is peaking. They don’t ripen further after harvest, so get good at determining watermelon ripeness. I wrote about that in my August post. An unripe watermelon is a sad waste, as most plants only produce two melons.
We store our watermelons outdoors, under the eaves of the house, where they will stay in good shape for a few weeks. We used to store them under the trees further from the building, but the squirrels learned to bite their way in, and taught each other the trick!
When we have enough watermelon harvested (500-600), we roll up the drip tape and disk the plot, to get a good stand of winter cover crops. We use winter wheat and crimson clover if before October 14. I’ll address this more next month. We used to try to harvest every last watermelon until the year I realized that we can only eat so many, and that watermelons in October are of limited interest. Good cover crops are important for taking care of the soil mini-livestock.
Winter Squash harvest happens once a week throughout September and October. This is next week’s blog topic. Winter squash is very rewarding to grow, providing high yields for not much work. Stored winter squash can provide meals all winter and also in early spring when other crops are scarce.
Zucchini and summer squash are still being harvested every day. Our last sowing was August 5. We harvest beyond the first fall frost, by covering that last planting with rowcover on chilly nights. See above, under Beans for our thinking about fattening up the last fruits.
From storage: spring cabbage, carrots, garlic and potatoes; watermelon from under the trees or the roof overhang.
Workhorse Crops Special Topic: Garlic Storage
Between late September and early October, we move our stored garlic from the basement to the walk-in cooler. the garlic was stored in the basement from June to the end of September, where the temperature was above 56°F (13°C) which is a perfectly fine storage temperature for garlic. Once the basement gets colder than that, we move the garlic to the refrigerator, where it will be below 40°F (10°C). The temperature range of 40°F to 56°F (10-13°C) is where garlic sprouts readily.
We like to eat lettuce year round, and have put time and energy into finding the varieties and planting dates that work best here in Central Virginia, as well as how to get the best results in each season. Recently I revised our lettuce schedules, partly to take account of hotter weather arriving earlier in the year, and also to even out the harvest dates.
I have frequently written blogposts about growing lettuce. And I have a whole year of Lettuce for the Month posts. See here for the overview, or click on the month you want to know more about. These posts are mainly about our favorite varieties for each time of year.
Back in 2006, I wrote Lettuce: Organic Production in Virginia for VABF. We’re now in Winter Hardiness Zone 7a. Back then we were 6b. Read this publication for details you are hazy on, but see our updated Lettuce Varieties List and Lettuce Log in this post.
Choose appropriate lettuce varieties for each time of year.
Sow several varieties each time to spread the harvest season and the risks of poor germination. I like to use something fast, something slow; at least one red; a romaine, a bibb and a couple of leaf types.
Consider multileaf lettuces too, Salanova and Eazyleaf brands. They are bred for uniformly small leaves, with more texture, loft and flavor than baby mixes and faster harvesting. Transplanted 6″–8″ (15-20 cm) apart they produce 40% more than baby leaf mixes. The full-size plant can be harvested as a head, providing a collection of bite-sized leaves. Or just one side (or the outer leaves) of the plant can be cut and the plant will regrow for future harvests. Growing multileaf heads takes 55 days, compared to 30 days for baby lettuce
Our recent changes to our Lettuce Varieties List include switching over from “Early Spring” varieties to “Spring” varieties at the end of February rather than the end of March. This means we only make 3 sowings of the early spring varieties, and we need to stop buying much seed of those varieties! Next year I might even abolish that category and those early varieties to simplify life.
The spring varieties we now sow from February 28 to April 22. We used to sow these until May 15. We’re still making 5 sowings of those, but the dates have moved earlier.
On April 23 we switch over to our Summer varieties, which we make 20 sowings of, until August 14. (Buy lots of seed of those varieties!) We then switch to nine sowings of Fall varieties, until September 7.
From September 8 to the end of September we use our cold hardy varieties. These 9 sowings include those for the greenhouse and hoophouse, which will feed us all winter.
You’ll need a large screen, a magnifying glass or the ability to expand the image.
We like to grow a balance of leaf lettuce and head lettuces, and, in winter, baby lettuce mix too. We harvest the baby lettuce mix when 3″–4″ (7.5–10 cm) tall, cutting 1” (2.5 cm) above the soil. We harvest leaves from the big lettuces the rest of the time. Baby lettuce mix is very pretty, but I actually prefer the juiciness and crunch of big lettuce.
Keys to year round lettuce
·Store seed in a cool, dry, dark, mouse proof place.
·Grow your lettuce quickly, for high quality and flavor, using good soil preparation and high organic matter.
·Learn the skills of lettuce germination in all weathers. Minimum soil temperature for germination is 35°F (1.6°C). Optimum temperature range for germination is 68°F–80°F (20°C–27°C).1/4″–1/2″ (6–10 mm) deep is ideal. Good light.
Watch the temperature – Germination takes 15 days at 41°F (5°C), 7 days at 50°F (10°C), 3 days at 68°F (20°C) and only 2 days at 77°F (25°C). Germination will not occur reliably at temperatures hotter than 86°F (30°C).
Keep watching the temperature – Optimum growing temperatures are 60°F–65°F (15°C–18°C), Some growth occurs whenever the temperature tops 40°F (4.5°C).
·Choose good locations! We grow lettuce outside from transplants from February to December (harvesting from late April); in a solar-heated greenhouse from September to March (harvesting leaves from November) and in a solar heated hoophouse from October to April (harvesting leaves from November, and whole heads in April). We also sow baby lettuce mix in the hoophouse from October to February, for harvest multiple times from December to April.
·Use shade cloth on hoops in hot weather
·Use rowcover in cold weather, or plant in cold frames, greenhouses or hoophouses.
Lettuce under shade cloth. Photo by Nina Gentle
Grow a consistent lettuce supply using succession crop planting
To have a continuous supply, it is important to plant frequently, at intervals adapted for the time of year. The gap between one sowing and the next gets smaller as the year progresses; the gap between one transplanting and the next does likewise. The number of days to reach transplant size dips to 21 days in the summer, then lengthens as the weather cools and the days get shorter.
We made a Lettuce Succession Crops graph using our records for sowing date and harvest start date. From this we determined the sowing dates to provide us with a fresh harvest (120 heads of lettuce, or equivalent) every single week. We made a Lettuce Log with our planned sowing, transplanting and harvest dates. This is explained in my slideshow Lettuce year round.
Lettuce Succession Crops Graph
Recently I fine-tuned this in light of more recent records. In some cases we had been led astray by a spreadsheet date calculator that was based on 30 day months in a 360 day year! Not reality! We also had data showing that transplants were not always ready on the dates we had thought, probably due to a mistake in an earlier year when we were unable to transplant on time, and repeated the delayed date the next year. Most of the tweaking was in early and late spring, and then in August.
Tips for growing good quality lettuce
I recommend transplanting lettuce (other than baby lettuce mix) at 4-6 true leaves (3-6 weeks of age). It is worth learning good transplanting skills, so that plants thrive, even if transplanted in mid-summer.
Water enough, with an efficient irrigation system. Water new transplants daily for the first 3 days, then every 4-7 days after that. Lettuce needs a relatively large amount of water throughout its growth. Deeper weekly waterings equivalent to 1” (25 mm) of rain are better than frequent superficial irrigation – roots will grow deeper, giving the plant greater drought-resistance.
To make best use of space and time, plant lettuces 10-12” (25-30 cm) apart, in a hexagonal pattern. If you plant too close, you are restricting the size of the lettuce. If you plant with more space than needed, you will waste time dealing with more weeds!
Transplanting gets a head start on weed control, which is important from planting to a couple of weeks before harvest. Don’t waste time hoeing lettuce you will be harvesting next week. I generally find that if I hoe once, a couple of weeks after transplanting, that is all the weed control I need at the fast-growing time of year. We like the stirrup, or scuffle, hoes, which are safer in the hands of novices than sharp edged hoes, because the blade is in a closed loop.
Some growers use black plastic mulch, but I hate filling the world with single use plastic, so we don’t do that. Some others use landscape fabric with melted holes at the right spacing. I used this for strawberries and liked it. I’m not sure I’d find it worthwhile for fast-growing lettuce. No-till growers can transplant into mulch, first making what we call “nests” at the appropriate measured spacing. It’s tempting to skip the measuring, but if you drift from a 12” (30 cm) spacing to a 15” (38 cm) spacing, you will end up with fewer lettuces!
For those who like to direct sow lettuce, you could prepare the bed, let it rest for a week (watering it), then flame or lightly hoe the surface before sowing to remove a flush of weeds.
Bolting and/or bitterness are more likely with under-watering, long days, mature plants, poor soil, crowding, high temperatures, and vernalization—once the stems are thicker than 1/4″ (6 mm), if plants suffer 2 weeks of temperatures below 50°F (10°C), followed by a rapid warm-up.
Deal promptly with pests and diseases. Aphids, cutworms, slugs, rabbits, groundhogs and deer all like lettuce as much as we do. If you find your lettuces melting down with fungal diseases, you can, of course, commit to better crop rotation. You can also consider solarizing beds for next year’s lettuce. You need a minimum of 6 hot weeks in which to cook the soil-borne disease spores by covering the prepared beds tightly with clear plastic. Old hoophouse plastic is ideal – construction plastic does not have the UV inhibitors that prevent the plastic shattering into shards.
If you haven’t already made a plan for winter cover crops, this is a good time to do it. Having plants growing through the winter, or at least into the winter until they get killed by cold temperatures, will improve your soil both physically (the roots hold the soil in place, preventing erosion, and they open up channels that improve the drainage) and biologically (the soil microorganisms thrive when they have active plants to cooperate with, exchanging nutrients). Cover crops will also reduce the number of weeds you have next year, because they crowd out weed seedlings. In some cases they even inhibit weed seeds from germinating.
I have some slideshows about cover crops, and am including one at the end of this post.
Choosing the “perfect” cover crops can be confusing, but any is better than none, so I encourage you to experiment and keep records, so you can improve your choices each year. It helps to know your first frost date, and your winter-hardiness zone (the lowest temperature your garden is likely to encounter). A two-week delay in sowing can seriously reduce the effectiveness of the cover crop, so follow these guidelines if you can.
Short Simple Guide to Winter Cover Crops
If the area has been fully harvested of food crops by 60-80 days before frost, sow a frost-killed cover crop or even a fast-growing food crop. Buckwheat, soy, cowpeas, spring peas, sunnhemp, Japanese millet, sorghum-sudangrass will frost-kill. Forage radish lab-lab bean or bell beans will die back and leave almost bare soil. Don’t sow a winter cover crop yet. If sown too early, oats head up in the fall and even drop seed.
If the area is clear of vegetable crops by 40-60 days before frost, sow oats to winter-kill. If possible add a legume (soy and spring peas are easy, and will be killed by the frost, so they won’t complicate food crops next year). For us with a first frost date of October 14, the cut-off date for oats is September 7. This would be after growing early sweet corn, spring broccoli, cabbage, spring-planted potatoes or early season spinach, lettuce, beets, carrots. Oats will winterkill completely at 6°F (-17°C) or even milder than that, leaving the plot quick to prepare for early crops next year. So plan to put your early crops where you had oats in the winter. See the slideshow for more about oats.
If the area is ready for cover crops 20-40 days before frost, sow winter wheat. Add a legume such as crimson clover, if you won’t need to prepare the area before it flowers (in central Virginia 4/16-5/2, most usually around 4/20). You get the most nitrogen from the legumes if they reach the flowering stage before you kill them off in spring. If you have a legume that doesn’t reach flowering, it’s not the end of the world, you just get less nitrogen for your money. It is too late to usefully sow cover crops that are not frost-hardy, or even oats, which won’t make enough growth before getting killed.
If the area is ready for cover crops up to 10 days past the frost date, sow winter wheat or winter rye and hairy vetch or Austrian winter peas. Winter rye is hardier than any other cover crop and can take later planting dates. But it is a bit harder than wheat to incorporate in the spring. Austrian winter peas can be sown later than other legumes.
If you are up to3-4 weeks past your average frost date, (we choose November 7 here, where our average first frost is October 14), sow winter rye alone. It’s too late for any legumes.
If you are later than 3-4 weeks past your average first frost date, leave the weeds or crop remains growing. It’s too late to sow a cover crop, and you’ll do more harm than good tilling up the soil. You can mow the weeds anytime you see lots of flowers and seed heads. The weed roots will hold the soil together and help feed the soil microorganisms until early spring. Be prepared to act soon in spring, so you don’t get weed seeds.
More Options for Each of These Time-frames
60-80 days before frost: You could follow a frost-tender cover crop with an over-wintering cover crop, for best effect. If you leave the dead tender cover crops in place, in early spring the winter weeds will start growing in the open space, so be ready for fast action. For the very earliest spring crops, forage radish lab-lab bean or bell beans will die back and leave almost bare soil. While still growing, they suppress weeds. BUT fast-maturing spring vegetables will not do well with no-till cover crops unless you add N fertilizer, as they need nitrogen more quickly than can be got from no-till.
40-60 days before frost: Austrian winter peas, crimson clover, or red clover are other options for legumes, but they won’t die when the oats do. They are relatively easy to incorporate in spring. Frost-killed cover crops can also be combined with oats. Or for a cover crop to survive the winter, sow winter barley or winter wheat with Austrian winter peas, crimson clover, hairy vetch, red clover, fava beans. Hairy vetch takes a few weeks longer than crimson clover to reach flowering. Which you choose will depend what you want to grow there next spring and when you need to plant it. After oats or other winter-killed cover crop, we like to plant our early spring food crops, peas, cabbage, broccoli, carrots, March-planted potatoes, spinach and the first sweet corn.
20-40 days before frost: Winter rye, or winter barley are also options for the cereal grain part of the mix, if you have those seeds on hand. In central Virginia, it’s a mistake to sow rye as early as August, as it can set seed. Austrian winter peas, or red clover are other legume options if that’s what you have. Sometimes it pays to use what you already have, as it may not give good germination if saved over to next fall. Winter rye needs 3-4 weeks after tilling in, in spring, to break down and to disarm the allelopathic compounds that stop small seeds germinating. Plan for the next food crops to be ones planted after late April, such as late corn plantings, winter squash, transplanted watermelon, tomatoes, peppers, sweet potatoes, June-planted potatoes, fall brassicas, and second plantings of summer squash, cucumbers, beans.
Up to 10 days past the frost date: it’s too late for clovers. Austrian winter peas winter-kill in zone 6, but are hardy in zone 7. Hardy to 0°F (-18°C). AWP bloom in late April at Twin Oaks, before hairy vetch. Suitable crops in the year before using Austrian winter peas are the late-finishing winter squash, melons, sweet potatoes, tomatoes, peppers, middle sweet corn, June-planted potatoes. The same group of crops are suitable for following AWP, as they are planted after May 1. You can sow AWP several weeks later than clovers, but at least 35 days before first hard freeze (25°F/-4°C) – in zone 7, 8/10–10/24 (11/8 is sometimes OK)
Up to3-4 weeks past your average frost date: no really, it’s too late for any other cover crop. If you don’t have winter rye, don’t till! Leave the weeds, see below.
Later than 3-4 weeks past your average first frost date: no, really, do not till! You could mow and tarp, to kill the weeds before spring. I’m not sure what the soil life thinks about that, though! You could mow again in early spring, or till and sow oats, if you won’t be planting a food crop in the following 8 weeks, giving the oats time to make respectable growth before turning them under.
Create a crop rotation for vegetables that includes good cover crops
If you include winter cover crops when planning a crop rotation for your vegetables, you can tweak your plan to maximize your cover crop opportunities. Here’s the steps:
Figure out how much area is needed for each major crop (the ones needing the largest amount of space).
Measure and map the space available
Divide into equal plots big enough for your major crops
Group compatible crops together to fill out each plot
Set a good sequence, maximizing cover crop opportunities
Include best possible cover crops at every opportunity
Try it for one year, then make improvements
For more details, see my slideshow Crop Rotations for Vegetables and Cover Crops on SlideShare.net
Advanced Options for Winter Cover Crops
Sometimes you can undersow the cover crop between the rows of a growing food crop, to take over after the food crop dies of frost or mowing. We do this with our last planting of sweet corn, and with fall broccoli and cabbage.
Timing is critical: Sow the cover crop late enough to minimize competition with the food crop, but early enough so it gets enough light to grow enough to endure foot traffic when the food crop is harvested. The leaf canopy of the food crop should not yet be closed. Often the best time is at the last cultivation, often about a month after planting the food crop. With vining food crops, it’s important to sow the cover crop before the vines run.
Choose vigorous food crops, but cover crops that are only moderately vigorous. Ensure the seedbed is clean and the soil crumbs small enough. Use a high seeding rate, whether broadcasting or drilling, and irrigate sufficiently.
No-till Winter Cover Crops
In the spring, kill the cover crop without tilling it in, and plant food crops into the dying residue. There are three ways to kill cover crops without herbicides:
Winter-killed cover crops for early spring food crops
Mow-killed cover crops.
Roll-killing (but it usually requires special equipment).
We have had one year in 10 as a no-till year. We use no-till cover crops before Roma paste tomatoes, which are transplanted in early May. We don’t need early-ripening for these, making them a good no-till food crop. The soil under no-till cover crops stays colder than tilled soil, slowing the plant growth down.
Late-spring transplanted crops such as late tomatoes, peppers, eggplant, Halloween pumpkins, or successions of cucumbers and squash can do very well after a winter-hardy legume-grass mix no-till cover crop.
To be an effective mulch, you need to get a thick sturdy stand of cover crops, which means sowing in plenty of time, and being generous with the seed. To make the timing work, you need a previous food crop that finishes before the sowing date 4-5 weeks before the average frost (that’s September 7-14 for us).
Timing is also critical in the spring. For maximum N, the legumes in the mix will be flowering right when you need to plant the food crop. Mow the cover crop mix close to the ground, and plant right into the stubble. Transplants or big seeded crops work well. The ground will be relatively hard – you probably can’t make a furrow for small seeds).
It’s not all over with the weed-prevention after that. In our humid climate the no-till mulch biodegrades after 6-10 weeks. In July we roll hay between the rows, to top up the mulch.
I’m back again with my series of 14 Workhorse Crops (including two pairs) to focus on monthly until April 2022: These are crops that we can rely on under a wide range of conditions. Some Workhorse Crops are easy to grow, some pump out lots of food, some are “insurance crops”, some are especially profitable (for those growing for market), and watermelons are more of a circus pony than a workhorse!
I hope this series will help you become more efficient, productive and profitable (if selling) as your lives resettle. Maybe you are not at home as much as last year, but you’ve learned to deeply appreciate growing your own food. So you need to choose less time-consuming crops and growing methods. You can use the search box to find previous month’s entries, such as July.
Workhorse Crops to Plant in August
In August here in central Virginia, the heat is still oppressive, but the day-length is definitely getting shorter. We and our crops have a longer night in which to recover for the next hot day. I remember the year I realized we just had to do some of our broccoli transplanting in the late afternoons, because the evenings no longer held enough daylight! Since those days we have reduced the size of our fall broccoli planting!
This month we will really need to plan for our fall and winter garden and execute our plan. There’s no making up for lost time in the fall! As the days get shorter and the temperatures (thankfully) start to drop, plants take longer to mature. A delay of a day or two in sowing leads to a delay of a week or two (or more) in the start of the harvest. Keep records and try several dates, especially if this is your first year, so you can fine tune your plan next year.
In August we can plant 8 of our 14 Workhorse crops in central Virginia.
Beans, zucchini and summer squash
These warm-weather crops get their absolute last chance before the season gets too cold. We sow our last bush green beans 8/1-8/3, and zucchini, summer squash and cucumbers by 8/5 at the latest. If you are in a colder climate than ours, with a first frost earlier than our October 14 average, your last sowings of beans, zucchini, summer squash and cucumbers were in July. It’s too late for us to sow edamame or sweet corn. More on Last Chance Sowings in the Special Topic at the end.
We also reach our Last Chance for carrots for the year. We usually make a huge sowing of carrots on August 4, as our storage crop for the winter. We need 1500 pounds of carrots to feed us through the whole winter (30 bags). We sow 4000 row feet (1220 m), usually on temporary beds where we grew garlic until June, followed by a round or two of buckwheat cover crop before preparing the beds for the carrots. It really pays with carrots to reduce the weed level. We mulch our garlic and weed it every month from February until we remove the mulch when we see scapes in mid-May. Few weeds grow in the three weeks before we harvest. Buckwheat is a fast growing summer cover crop that is a modest size and easy to manage. It flowers about 4 weeks after sowing, and the flowers attract many beneficial insects.
After sowing the carrots with our trusty EarthWay seeder, we keep the soil damp by nightly watering until we see the red hooped stems of our indicator beet seedlings emerging. Then we know it’s time to flameweed. It’s usually the fourth day after sowing the carrots. This dispatches any new weeds thinking of emerging. As soon as we can see well enough to do so, we hoe between the rows with our scuffle hoes (stirrup hoes). Once the carrots are 1” (2.5 cm) tall, we hand weed, cultivate with claws (to kill weeds that haven’t even emerged yet) and thin to 1” (2.5 cm). Later we thin to 3” (7.5 cm) and weed again. That’s a September task.
Cabbage and Collards:
For the cool weather greens we are in our second season for the year. August is too late for us to start broccoli, collards or cabbage. In July and August we transplant the starts we sowed in June and July. At this time of year, we aim to transplant brassicas at four true leaves (3-4 weeks after sowing). In hot weather, use younger transplants than you would in spring, because larger plants wilt from high transpiration losses. If we find ourselves transplanting bigger plants, we remove a couple of the older leaves to reduce these losses.
To avoid flea beetles and harlequin bugs, we cover the nursery seedbeds until we transplant, and then cover the transplants for four weeks, until the plants are big enough to survive bug bites. Nets are better than rowcover in hot weather, as airflow is better and heating is less. This might require a bit of re-planning to get best value from the netting. For example – instead of planting the rows an equal distance apart, plant two rows closer than before, and then have wider aisles. One width of netting can cover two rows of brassicas, each with their own (offset) hoops.
Dubois Agrinovation has a range of ProtekNet Insect Exclusion Netting, made of clear high-density knitted polyamide (lighter weights), polypropylene/olefin (mid-weight) or polyethylene (heavy weights), with UV resistance. Be sure to buy the size mesh that keeps out the pest you are guarding against. See the Dimensions and Specifications tab on their website. We have bought the 0.0335″ x 0.0335″ (0.85 mm x 0.85 mm) mesh (against harlequin bugs) and the 0.0138″ x 0.0138″ (0.35 mm x 0.35 mm) mesh against flea beetles. Pieces can be sewn together, or Dubois will join them with zippers. See the Details tab for the insects excluded by each particular mesh. Light transmission is 88-93%. Ours have lasted many years, longer than rowcover. Use hoops to hold the mesh above the plants so insects can’t lay eggs through the holes. Purple Mountain Organics sell the whole range in full rolls, and the 25 g in 6.9’ x 33’. Johnny’s Seeds sells 6.9’ x 328’ 25 g “Thrips Net”. Compare shipping charges as well as netting price.
Two weeks after transplanting, we till or wheelhoe between the rows and hoe around the plants, removing the minimum amount of netting at any one time that we have to. Four weeks after transplanting, we remove the netting entirely, and hoe and till again. This time we undersow with a mix of clovers to be a long-term cover crop.
We sow 6 beds of kale, two every 6 days, (8/4, 8/10, 8/16, and if we need to resow, 8/24) until we succeed in getting enough established. We focus our attention on the two newly sown beds, watering daily as needed, until the seedlings emerge.
We want a lot of kale, and there isn’t time to transplant it all. We grow Vates dwarf Scotch curled, the most cold-hardy variety I’ve found. It isn’t huge – we plant 4 rows per bed 10″ (25 cm) apart. We’re looking at 6x4x90 plants.
We carefully thin, leaving one plant every foot (30 cm). Often we’ll get patchy emergence and we use the carefully dug thinnings to fill gaps and to plant other beds, at the same plant spacing. Our mixed direct-sow/transplant method allows for the fact of patchy germination, and requires less watering than if direct sowing it all at once. If your climate is a colder zone than ours, you would start sowing kale in July. We cover the beds with Proteknet.
Kale make some growth whenever the temperature is above about 40°F (5°C), which happens in our winters on many days, making this a valuable winter crop.
Chard: Swiss chard can be sown here in July or August, for a good fall harvest, with the option of overwintering under rowcover. It grows small leaves after only 35 days, and full-size leaves after 50 days. Chard is not eaten by flea beetles, and does not have problems germinating in hot weather like spinach does. Chard is our poster-child insurance crop! So easy! So productive!
Workhorse Crops to Harvest in August
Eleven of our 14 workhorse crops can be harvested in August!
Beans can be harvested here from late June until the first frost (or later if we cover the beds with rowcover when a frost threatens).
Cabbage planted in the spring is ready here from late May until mid-July, or a little later if we planted late-maturing varieties. When I was a new gardener I thought “early varieties” were to be planted early, and “late varieties” to be planted later. It would be clearer if they were labeled “fast” and “slow”! For the second half of the year, late varieties need to be sown earlier than early varieties to get a harvestable crop before it gets too cold. Be sure to check and compare the days to maturity numbers for the varieties you are growing.
We store enough spring cabbage to feed us until we start harvesting fall cabbage. It’s about a 50lb (25 k) bag a week. Fall planted cabbage won’t be ready until September 25.
Carrots: After May we hope not to need to sow more carrots until the beginning of August, because carrots grown in hot weather don’t taste sweet and can even be soapy. But home-grown hot weather carrots are still better than industrial carrots from thousands of miles away. This year we finished harvesting our spring carrots in July and stored them in the walk-in cooler.
If we have not grown enough carrots in the spring, we sow in June, or July if we must. When we do sow in June and July, those carrots are ready about 2-3 months after sowing (less time in warm weather, longer as the weather starts to cool in the fall)
Chard can be harvested whenever you want some. Just snap or cut off some outer leaves and stand them in a bucket with a little water (or if your cooler isn’t as big as ours, put them in a loose plastic bag in your fridge) until you cook them. For sustainable harvesting levels, we use our standard leafy green mnemonic “8 for later” meaning that we make sure to leave at least eight of the inner leaves on each plant, as we harvest the outer leaves. With chard, we can take a couple more than this, but we don’t want to exhaust our workhorses!
Chard is biennial, and will not bolt the first year (unless stressed by lack of water). Red chards bolt more easily than the green ones, presumably red crops are a bit stressed already, as they are short of chlorophyll, compared to the green ones, making photosynthesis harder work.
To overwinter chard in our climate, we cover the bed with rowcover on hoops. We can continue to make harvests into early winter. The mulch and rowcover help keep warmth in the soil, which keeps the crop growing.
The outdoor killing temperature for unprotected Bright Lights chard is 22°F (–6°C); red chard survives down to 15°F (–9.5°C) and green chard to 10°F (–12°C). If you want to overwinter chard in a climate colder than those temperatures, you can make a heavy harvest just before the weather turns seriously cold. This leaves the growing points of the plants alive. Cover the whole bed with thick straw or hay and wait for spring.
Potatoes, if planted in April would be harvested in August here. We can plant potatoes between mid-March and mid-June, leading to harvests in July-October. It’s as important not to leave potatoes baking in the sun as it is to protect them from frost, both when planting and when harvesting. Read more about potato harvest here.
Sweet Corn harvest is well underway. Usually we start sowing as early as possible and hope to start harvesting on 4th July. Sweet corn will be ready to harvest about three weeks after the first silks appear. This year we are later, but it’s just as delicious. We harvest 3 days a week, which gives us a nice amount from our 1050-1325 ft (320-400 m) plantings to feed our community. Some growers say you should harvest daily, but we find every other day is often enough. We are able to rush our sweet corn straight to the cooler, and it doesn’t have to travel after that, so we enjoy very fresh corn. Be sure to shade your corn after harvest and get it cooled as soon as possible, as the flavor deteriorates if it sits around.
Determining sweet corn maturity can be hard for new growers. Corn is ready when the silks become brown and dry. If the silks are not brown, just walk on by! If they are brown, and the ears are plump and filled to the end with kernels, take a closer look. Mature ears stand away from the stalks. This is called “flagging”. If you are still unsure, and don’t want to make too many mistakes, slit the husks at the side of the ear with your thumb nails and look at the kernels. (Don’t puncture the husks on the top of the ear as the dew and a million tiny beetles will get in and make a mess.) They should be a bit squarish and tight packed, not round and pearly with spaces between them. An opaque, milky juice will seep out of punctured kernels. If your sample ear wasn’t ready, push the husks closed over the cur and wait a few days.
Tomatoes are ripening fast outdoors now. Wait for the leaves to dry from rain or dew, before touching the plants, to minimize the spread of fungal diseases. Lightly press the bottom of the tomato to make sure it is soft enough to be fully ripe. Snap the tomato off at the knuckle, so that the plant gets the signal the fruit has gone, and will ripen more. We pop off the green calyx and set the tomatoes in plastic crates that fit two or three layers of fruit. It’s always tempting to include cracked ones, but they quickly turn nasty, so only do that if you are going to sort them promptly and process the damaged ones.
Watermelon harvest is starting. Determining ripeness is both art and science, and it’s worth getting good at it, as harvested watermelons don’t ripen further after harvest. An unripe watermelon is a sad waste.
The first step is to look at your sowing date and the days to maturity for the variety you’re growing. If it’s too soon for them to be ready, don’t tempt yourself by looking! If the dates are auspicious, the next step is to look at a big melon and find the curly little tendril that grows from the vine where the melon is attached (but on the opposite side of the vine). It must be brown and dry. If not, leave the melon untouched!
If it is brown, you can slap the melon and listen. The sound should be like thumping your chest, not your head or your belly! If that seems to indicate ripeness, we have one last check, that works for Crimson Sweet. I’m not completely sure it works for all varieties, although I think it should. Stand astride the melon, bend and put your flat hands, heel to heel, over the width of the melon. Pause and ensure silence (if you have coworkers) and then press down firmly with quite a bit of weight. If the melon is ripe, you will hear and feel a scrunch, as the ripe watermelon flesh splits inside the melon. Then you know you have a really good one. Rural legend says this test only works once, so don’t practice, just do it for real!
Cut the melon stem and gently lift and set the melon down in the cart, truck or at the side of the patch. I know some crews throw the melons from one person to another, but Crimson Sweets are too big, in my opinion.
Note that these rules apply to watermelons, not to any other type of melon.
Zucchini and summer squash in our climate need harvesting every day, if we are going to avoid blimps. Summer squash can be twisted off the plants, but zucchini need to be cut. The hairs on the leaves, combined with sweat, can cause unpleasant itchiness. Wear long sleeves or make special sleeves for this job that are not attached to any particular shirt. Make a casing and insert elastic around the top edge (and the bottom, if there are no cuffs). These sleeves can be bought, but everyone probably has an old shirt and could make their own.
We harvest every day to the fall frost (or beyond if we remember to cover that last planting with rowcover on chilly nights.).
From storage: spring cabbage, carrots and potatoes.
Workhorse Crops Special Topics for August:
Formula to Calculate Last Planting Date for Warm Weather Crops
To calculate the last worthwhile sowing date for warm weather crops, add the number of days to maturity and the length of your desired harvest period, and subtract this number from your average first frost date. Using yellow squash as an example:
Number of days from seeding to harvest 50
Desired length of the harvest period 21
14 days to allow for the slowing rate of growth in the fall 14
14 days to allow for an early frost (but we have rowcover) 0
Days before the first frost = total of these = 85
Last date for sowing, with October 14 first frost date = July 21
But by throwing rowcover over the last planting during cold spells, we effectively extend the growing season by 2 weeks, and we can sow our last planting of squash on Aug 5.
Last Chance Sowings: Fast Fall Crops for When Time is Short
Some crops mature in 60 days or less. These are mostly greens and fast-growing root vegetables. They are useful to fill space and time before you plant winter cover crops.
Ready in 30–35 days:
arugula, frilly mustards, kale, radishes.
some Asian greens: Komatsuna, Maruba Santoh, mizuna, Tokyo Bekana.
beets, Napa cabbage, small cabbages (Farao or Early Jersey Wakefield), collards, kohlrabi, pak choy, turnips
Use the chart below to figure out your last chance to sow crops with various days to maturity
Sowing dates for fall crops with various days to maturity
For example, Early Purple Vienna Kohlrabi takes only 60 days from sowing to harvest in spring. Allow for the slowing rate of growth in fall (unless you will use rowcover). Kohlrabi is hardy to maybe 15°F (-9.4°C). When is it likely to get that cold? Not before the beginning of November here, so counting back 31 days in October, plus 30 in September, plus 31 in August – that’s 92 days already, more than enough. We could sow kohlrabi in early August and get a crop at the end of October.
Aphids can get out of control in early spring as they become active before their native predators, such as ladybugs, emerge from hibernation. We have a particular problem in our hoophouse and in our greenhouse on the eggplant, pepper and tomato transplants from mid-April to mid- to late-May depending when we manage to get them under control.We’re planning now, so we can be ready next spring.
There are many kinds of aphids. The lifecycle of aphids starts in spring with eggs hatching into wingless females that give birth via parthenogenesis to more females. Within a week, one female can produce 100 clones, which can repeat the process at the age of one week.This continues until adverse weather or predators trigger production of a generation of winged female aphids that moves to new plants. Later in summer male aphids are born and females lay fertilized eggs that overwinter on host plants, to hatch the following spring.
Climate change is making the problem worse: for every 1degree Celsius rise in average temperature (about 2 F degrees), aphids become active two weeks earlier.
Organic Integrated Pest Management
I have a blog post about our organic integrated pest management, a step-by-step method of pest management which starts with actions least harmful to the ecosystem, only employing biological controls such as botanical sprays and selective pesticides if necessary after all other steps have been insufficient.
I recommend the ATTRA online publicationOrganic Integrated Pest Management. Each of the 22 pages is a poster, complete with good photos and concise clear info. Extension.org has an article on Organic Integrated Pest Management that explains how to tackle pest problems one step at a time with ecologically-based practices, starting with actions chosen to reduce the chances of the pest ever getting a grip on your crops.
Steps in Organic Integrated Pest Management:
Prevent infestation: Cultivate a good environment for your crops: healthy soil, sufficient space, nutrients and water, suitable temperature, soil pH. Practice crop rotation to reduce the chances of pests and diseases carrying over from one crop to the next. Clear old crops promptly, so they don’t act as a breeding ground for the pest. Choose suitable varieties that resist the pests you most expect.
Cover or protect the plants physically from the pests (mulches to stop soil-dwelling pests moving up into your crops, netting, rowcover, planting diverse crops, and even growing trap crops)
Provide habitat for natural enemies and other beneficial insects
Monitor crops regularly at least once a week and identify any pests you see.
Introduce natural enemies of the pest (bacteria, fungi, insect predators or parasites)
Hand pick and kill the pests if the pest population is above the action threshold. Many fruit and root crop plants can take 30% defoliation before any loss of yield. Where the crop is the foliage, this may be too much!
Use biological controls (often derived from natural enemies) if the damage is still economically significant after trying the earlier steps in the process.
Applying these principles to dealing with early spring aphids
1.Prevent infestation If you act before the aphids arrive, you can use a fine mesh netting to keep them off your plants, but monitor to make sure no aphids have got inside the net. Control ants (which farm aphids for their sweet excretions). Reputed repellents that I have not tried: dilute garlic, onion or chilies with water; diatomaceous earth (health hazard from inhaling gritty particles); vegetable oils.
2.Cover or protect physically. You could try trap crops of nasturtiums to draw aphids away from your crop, but how much of your space do you want to devote to nasturtiums, and how do you deal with them then? The same choices as on food crops.
3.Provide habitat for natural enemies. Plant for a continuous supply of insect-attracting blooms, that flower early in the year and attract aphid predators such as ladybugs, lacewings, syrphid flies (hoverflies), damsel bugs, big-eyed bugs, and spiders. Grow some early blooming flowers with pollen and nectar they can use as alternative foods. Sow seed in fall for earliest bloom.
Native annuals are some of the earliest bloomers that attract beneficial insects:
Tidy Tips (Layia platyglossa), a spring flowering wild annual in the aster (sunflower) family. The white tipped yellow daisy like flowers are 2” (5 cm) across. A native of California, it grows up to 2ft (60 cm) tall. The seeds attract birds. Flowers have special value to native bees. Tolerates cold to -5°F (-20°C). Likes full sun. Seed is widely available. To start indoors, sow seeds 6 to 8 weeks prior to planting outside. Do not cover; seeds need light to germinate. Seeds germinate in 8-12 days at 65-70° F (18-21°C). Temperatures above 70°F (21°C) inhibit germination.
Information from Laura Blodgett in the Daily Improvisations blog, Southwest Idaho: Starting Tidy Tips from seed in February was too early. The seeds sprouted within a few days. The plants were sturdy from the start. It was too cold to plant them out, but they had so much growth that they were cramped in their small pots. There were enough warm days in March to harden them off, even though temperatures got down in the mid 30’s F (1-3°C) a few nights.
Meadowfoam (Limnanthes douglasii) commonly known as poached egg plant and Douglas’ meadowfoam. The five-petalled 1” (2.5 cm) flowers have yellow centers and white edges. A fast-growing bushy annual, very attractive to hoverflies, butterflies and bees. Requires insect pollination. It grows 6-12” (15-30 cm) tall and wide. Hardy to zone 2. Germinate below 60°F (16°C) (in fall?). May need light for germination. Easy to transplant, but don’t let it dry out! If spring-sown, may not flower until early summer (too late for aphid control). Temperatures below 55°F (13°C) will hinder flower opening as well as honey bee flight.
Baby blue eyes (Nemophila menziesii) is a low spreading, shrub-like plant with succulent stems and flowers with six curved blue petals. It grows 6-12” (15-31 cm.) high and wide. You can expect baby blue eyes flowers in late winter where temperatures are moderate and the plant blooms until late spring to early summer. Wait until soils warm to nearly 60°F (16°C) to sow seeds. Sow shallowly, about 1/16 inch (2 mm) deep. Baby blue eyes flower will germinate in 7-10 days with cool weather and short days. Baby blue eyes self-seeds readily but does not transplant easily. Butterflies, bees, and other helpful insects use the nectar as food. Pinch the tips of the growth to force bushier plant formation. Once the plant has flowered and seed heads formed, cut them off and dry them in a paper bag. Shake the bag after a week and then pick out the larger pieces of chaff. Transplant carefully 6-8 weeks after sowing. Sow in the fall, (but not frost-hardy? winter hardy in zone 7 and warmer?) then blooms from early spring to mid-summer. Baby blue eyes will die out if too hot in summer. Water frequently, provide shade (without hindering insects!)
Borage is a warm-season annual, fast at producing nectar, taking about 8 weeks to flower from sowing. Borage grows 1-3 feet (30-90 cm) tall and wide; it blooms from early summer until the first frost in fall. Borage can be started indoors 6-8 weeks before the last frost. Seeds germinate in 7-10 days. Transplant borage seedlings outdoors after the last spring frost. Be careful when transplanting not to damage the taproot. Seeds can also be sown in the fall and will germinate the following spring.
Alyssum is a small plant we have used in broccoli and cabbage beds to attract beneficial insects. Sweet alyssum attracts three main groups of predatory beneficial insects a) Minute pirate bugs (they eat aphids, thrips, mites, psyllids, and insect eggs), b) Parasitic wasps (they lay eggs in aphids, beetles, flies, moths, sawflies, mealy bugs, and scales. The larvae hatch and eat their way out, killing the host. c) Hover flies, aka syrphid flies (the larvae feed on aphids). Alyssum flowers also attract butterflies and bees. Buy Sweet Alyssum, not the ornamental cultivars.
Shungiku, Chrysanthemum Greens, Chopsuey Greens, Glebionis Coronaria, is in the aster family, Asteraceae. It is native to the Mediterranean and East Asia. The plant’s greens are used in many Asian cuisines. Shungiku is easy to grow and the leaves, young shoots and stems can be eaten. Leaves are aromatic, with a strong flavor. Some describe the taste as between celery and carrots. Even the petals and seeds can be eaten. Small House Farm grows this (and sells seed). Bevin says it does attract bees, butterflies and predatory insects. It would probably do well in the winter hoophouse, and could be provoked into bolting early in the spring.
Dill is a biennial umbellifera, often grown as an annual. It is easy to grow, germinating in 10-14 days. It doesn’t transplant easily (although we do it every year without a problem). It does self-seed readily, so to prevent this, cut the seed heads before the seeds turn tan. The leggy plant grows 2-4 ft tall (60-120 cm) and half as wide. Each plant grows only one hollow stem with an umbrella-shaped flower head from mid-summer to fall (too late for spring aphid predators). Dill tolerates cold and heat, but will likely die back to the ground after the first hard freeze. It might not be the easiest to include in a hoophouse.
Angelica is a biennial that can flower in the spring of its second year.
Phacelia is a particularly useful perennial plant in early spring if it has overwintered as it is an early pollen source for bees coming out of hibernation. Sow in the fall for early spring blooms – Phacelia will survive mild frosts to bloom in spring. It winter-kills at approximately 18˚F (-8˚C). The seeds need darkness to germinate, and then the plants like to grow in full sun. Phacelia flowers from 6-8 weeks from spring sowing for a period of 6-8 weeks with lavender blooms that attract syrphid flies, bumblebees, honeybees and native bees, and also aphid predators like hoverflies and parasitic wasps. It can grow 6-40” (8-100 cm) tall, given the chance.
Yarrow is a perennial, hardy to zone 5. Common Yarrow (with flowers that range from white to red) is hardy down to zone 3. It attracts an array of beneficial insects. In addition, the scent of yarrow repels deer and mosquitoes.
Fennel,Foeniculum vulgare (common fennel), is an herbaceous perennial commonly grown as a summer annual. 5-7 ft (1.5-2 m) tall; each stem branches near the top and each branch ends with a flat-topped cluster of small yellow flowers; fennel looks very much like dill but is taller and coarser. Fennel blooms from mid-summer to frost. Too late and too tall for our goal of attracting spring aphid predators in the hoophouse.
Coyote bush, (Baccharis pilularis), also called chaparral broom, is a native shrub related to sunflowers. It may be a low-growing shrub or an erect tall bush, depending upon its growing conditions, and so may not be a good candidate for a potted plant in the hoophouse! It attracts syrphid flies, as well as bees and butterflies, with its abundant winter bloom.
Dandelions. If you decide to trust to weeds to feed your beneficial insects, take care about how much seed they sow!
4.Monitor crops at least once a week
5.Introduce natural enemies: We do have an aphid parasite in the hoophouse as we do find mummies, but not enough to control an aphid outbreak in spring. Parasitic wasps for aphids include
Aphidus colemani eggs hatch into larvae which feed on the nymphs from the inside, the nymph swells and hardens into a leathery, grey or brown colored mummy similarly to effects of Aphelinus abdominalis. Once larvae mature, adult A. colemani wasps chew their way out of the aphid mummy and emerge to seek out aphids. These parasites are a good choice for year-round use (in greenhouses and outdoors) as the short days of winter do not affect them. Optimum Conditions: 70-77°F (21-25°C), 80% relative humidity. Release rates: 500-3,000 per acre, 2-3 times at one week intervals, depending on the extent of infestation. This product controlsaphids, especially melon and cotton aphids Aphis gossypii, but also attack green peach aphid Myzus persicae, tobacco aphid Myzus nicotianae and bird cherry-oat aphids Rhopalosiphum padi. Price $243 for three batches of 500, including overnight shipping, from Arbico Organics.
Aphidus ervi will consume all types of larger aphids, especially the potato aphid, Macrosiphum euphorbiae, and the glasshouse potato aphid, Aulacorthum solani. It also parasitizes Myzus persicae var. nicotianae, as well as aphids such as Sitobion sp., Schizaphis sp., Rhodobium sp., Acyrthosiphon pisum and others. Use Aphidius ervi especially when aphid infestations are just beginning, as control will be easier to achieve before the aphid population’s explosion. Aphidius ervi are shipped in a 125 ml bottle that contains at least 250 mummies and adult aphid parasites. The bottle has a ventilated cap for optimum humidity. A sugar-water feeder ring ensures adult survival. Release the emerged adults within 18 hours of receipt. The parasitized aphid swells and hardens into a leathery, grey or brown colored mummy. The first mummies can be seen in the crop approximately 2 weeks after the first introduction. Use at the rate of 1 adult per 20-100 sq ft (1 per 2-9 m2) for preventative use. 250 mummies is sufficient for 5000-25,000 sq ft (460-2300 m2). Dose rate may be increased 5-fold for hot spots. Introduce A. ervi weekly for at least 3 weeks. Cost from Arbico is $101 including shipping each time, $303 likely. Monitor weekly and make further introductions as required. When pruning leaves, check for parasitized aphids (brown mummies) and if present, keep these leaves in the greenhouse until new parasites emerge. Because they fly as soon as they emerge, you need to cover doors and windows with mesh screens.
Another option is a predatory gall-midge, Aphidoletes aphidomyza, the larvae of which hunt and kill aphids. Kills over 60 species of aphids, especially those in greenhouses and hoophouses, including green peach aphid Myzus persicae; andthe hemlock woolly adelgid Adelges tsuga. Optimum conditions: 64-77°F (17-25°C) with RH of 70%. Shipped as pupae. The adults hatch within 1-12 days. After hatching, females lay eggs among aphid colonies. The eggs develop into larvae, and seek out adult aphids, injecting a toxin in their legs to paralyze them. Then they bite a hole in their thorax and suck out the body contents. Use 1 predator per 10 sq ft (1 m2), 2-3 predators per 10 sq ft (1 m2) for heavier infestations or 4,500 per acre (0.4 hectare) weekly until infestation subsides. 1000 for a 96x30ft (29×9 m) hoophouse, cost $125 including shipping per week, perhaps $375 total.
Green Lacewing adults feed on nectar, pollen, and aphid honeydew, and the larvae are active predators of soft-bodied insect pests: aphids, thrips, whitefly, leafhoppers, spider mites (especially red mites) and mealybugs. After hatching, green lacewing larvae seek out prey – pest eggs, nymphs or adults. They feed for 2-3 weeks, spin a cocoon, and emerge as adults 10-14 days later. Lacewings have the ability to tolerate wide temperature ranges and work well with most other beneficial insects. Green Lacewing Eggs:Best low-cost biological control for common garden pests. If you want to establish Green Lacewings at the beginning of the season or have a limited infestation, choose the appropriate numbers of eggs for your garden or greenhouse. It takes 3-10 days for larvae to emerge depending on the temperature and other environmental conditions. Repeat applications every 1-2 weeks. Green lacewing eggs are available in loose media or on hanging cards for easy release. Green Lacewing Larvae:Best for immediate treatment of a pest problem. If you have a more severe infestation, buy the larval frames or bottles, which provide the quickest means to control unwanted pests – the larvae arrive ready to feed. Adult Green Lacewings:Best for establishing a population. If you are treating a large area and want to create a stable population, buy adult lacewings. The adults come ready to lay eggs throughout the release area. They do not actively control pests themselves. Cost 1000 eggs on cards $30 each time; 1000 larvae $61 each time; 100 adults $85. All prices include shipping.
Ladybugs. live ladybugs are best used when pest numbers are low, but can be used to fight existing infestations. Ladybugs primarily feed on aphids, but will prey on a variety of other pests including mealybugs, thrips, soft scale, whiteflies and spider mites. Each adult can consume up to 5,000 aphids in a lifetime. The larvae eat 50-60 aphids per day.Optimum Temperatures: 62-88°F (15-31°C). Ladybugs are prone to flying away. Help keep them around and attract native species by planting perennial and annual flowering plants and by avoiding chemical sprays. Create shaded areas or plants with dense canopies to provide alternative habitat when conditions are not ideal. While these methods may not keep all the ladybugs on site, they should help. If you have had issues with ladybug flight, consider using Assassin Bugs or Green Lacewing instead. 4,500 for up to 2,500 sq ft (232 m2). Cost $20/1500 plus Overnight or 2nd Day Air shipping.
6.Hand pick and kill the pests if the pest population is above the action threshold. Handpicking aphids is likely impossible, so blast them off the plants with a water jet from a hose. This may decrease the population enough for natural predators to begin control.
7.Use biological controls. Failing success with the methods above, a soap spray can be effective, although aphid predators will also be harmed. We use 3 Tablespoons (15 ml) per gallon (3.8 l) of biodegradable Murphy’s Oil Soap, in a sequence of 3 sprayings 5 days apart. The soap needs to hit the aphids to kill them. Soak both sides of the leaves and directly spray any visible pests.Murphy’s Oil Soap is made from lye (potassium hydroxide) or sodium hydroxide, and vegetable oils with 2% of synthetic ingredients including trisodium MGDA, Lauramidopropyl dimethylamine oxide (a non-toxic purifying agent), sodium tallate. Official insecticidal soaps are made from potassium salts of fatty acids (potassium laurate).
Insecticidal soap works in several ways. The soap penetrates insects’ cuticles, which causes their cells to collapse and dry out. Soaps suffocate insects such as scale insects. Soap sprays are also somewhat effective against chiggers, earwigs, fleas, mites, scales, and thrips. They are not effective on chewing insects such as caterpillars and beetles.
You can make your own soap spray if you have some fragrance-free liquid soap. You do not need to include oil. Note that “dish soap” is actually detergent, not a soap at all, so don’t use that. Test your homemade spray on a small part of a plant first and wait 24 hours to see if there is any damage. Look for spotting, wrinkling, or browning of leaves. If you see any trouble, don’t use the spray.
Soap sprays can be potentially damaging to some plants. Crops that are susceptible to damage from soap sprays include cucumbers, squash, melons, beans, and peas.
Neem is a botanical insecticide effective against aphids.
Best Options for our Hoophouse in April and May
Looking at the options for dealing with aphids and choosing those most compatible with pot-grown plants to flower in spring in our greenhouse and hoophouse, these seem our best chances:
·Cultivate a good environment for our crops.
·Monitor crops regularly once a week.
·Grow Meadowfoam from seed in the hoophouse in late October. Hardy to zone 2. Try February too.
·Grow Tidy Tips from seed in the greenhouse in February, pot up and move into the hoophouse just before flowering. Try starting some in late October too. Tolerates cold to -5°F
Grow Sweet Alyssum from seed started in February.
Grow borage form seed started in February. Move pots to hoophouse after April 1.
Grow perennial phacelia started in October and February for future years. Phacelia will survive mild frosts to bloom in spring. Protect from worse than “mild frosts”.
Grow yarrow from seed started in October and February. It is hardy down to zone 3.
Grow Shungiku from seed sown in late September, and provoked into bolting early in spring.
If we want to spend $100+ to deal with a bad infestation, buy 3 units of ladybugs.
Book Review: Sally Morgan, The Healthy Vegetable Garden: A natural, chemical-free approach to soil, biodiversity and managing pests and diseases.
Chelsea Green Publishing, September 2021
Sally Morgan is an expert organic gardener in the UK. She is the editor ofOrganic FarmingMagazine for the Soil Association, the nation’s foremost non-profit organic gardening and farming membership organization. Her book The Healthy Vegetable Garden is clearly and concisely written. Sally promotes building healthy soil, boosting biodiversity, creating habitats to attract pollinators and predators, making good use of water, promoting the stability and resilience of natural ecosystems, and integrating the landscape with people.
A healthy garden maintains a balance where pest organisms are at a non-damaging level, (rather than eliminated entirely). Here you will find lots of solid information to identify pests and diseases and deal with them using regenerative principles, and when necessary, making traps and lures.
The book has some info particularly for US gardeners – you’ll be able to read about Mexican bean beetle and Colorado potato beetle! You might be mystified by some of the European details we don’t have to deal with, such as raspberry beetle or flatworms. As long as you have some prior gardening experience where you live now, you can only benefit from the information offered here. Brand new US gardeners might get confused.
The Healthy Vegetable Garden has good descriptions of soil and its components, structure, assessment, and testing. It is important to nurture healthy soils producing healthy plants, with the essential minerals and vitamins we need for health. Nutrient density has declined seriously over the last 70 years, particularly levels of calcium, iron and vitamins B and C. In 2014, the UN warned that we had only 60 years of harvests left, if we continued degrading our soils. In 2020 a new study estimated that 90% of soils had only 100 years of harvests left. Soils managed with conservation techniques have much longer projected lifespans.
The second chapter is about ways to regenerate soils, by minimizing tilling or digging, adding compost, mulches and cover crops. The living mulch section is where I am hesitant. My experience and that of Jesse Frost whose Living Soil HandbookI reviewed recently, is that living mulches can out-compete the crop if we are not skilled and careful. The author does point out the need to cut back the mulch to prevent this problem. Growers in the south might find planting zucchini (courgettes) into white clover impractical as zucchini is a fast-turnaround crop for us, whereas clover is a slow-growing cover crop. The author leaves the clover growing through the following winter, to make the combo work. In the chillier parts of the UK, only one crop of zucchini can be grown in a summer, so the system makes sense. In Virginia, we plant zucchini and summer squash 5 times outdoors. Likewise, the speed with which chickweed flowers and sets seed in Virginia would make it unwise to regard it as a cover crop! I did like the idea of undersowing tomatoes with coriander, if I wanted large volumes of coriander (cilantro).
The chapter on understanding pests and diseases is well-written, although we in the US have so many more than in the UK! Plant pests are listed in categories by their method of causing harm, rather than by individual names, which helps understanding. Plant pathogens likewise are described by type, as bacteria, viruses, fungi, water-molds. Fungal pathogens include biotrophs (parasitic pathogens such as downy mildews, rusts and smuts), semi-biotrophs that spend part of their lifecycle on the host, then part feeding saprophytically on the host’s dead remains (such as apple scab, Phytophthora blights, Botrytis-type molds and powdery mildews) and necrotrophs that kill their host and then feed as saprophytes. I appreciated the bigger understanding this classification of pathogenic fungi gave me.
Heed the warning that climate change is bringing new pests and diseases, and the chilling news that for every 1 Celsius degree rise in average temperature (about 2 F degrees), aphids become active two weeks earlier. Some warm climate diseases will move further towards the poles. The author recommends paying attention, encouraging good airflow around plants, sanitizing pruning tools, and planting rows of tall plants to break up the progress of air-borne fungal spores. Growing potatoes downwind of a row of Jerusalem artichokes is a good example.
Sally is very practical on the subject of sterilizing pots and flats – your tools, boots, gloves and hands are as likely to spread spores, don’t worry about sterilizing pots! Some of the disinfectants suggested in other books can do more damage! Likewise, most spores don’t survive long on the ground, removed from their host plants, and so such diseased crops can be safely composted in a hot compost process. Practice crop rotation to deplete those that do survive in the soil, such as carrot rust flies.
Under normal conditions, predators can prevent pest outbreaks, but problems arise when conditions change quickly and disrupt the balance of prey and predator. If you see lots of pests, find a way to deal with them that won’t also kill their predators and parasites. Beware broad spectrum pesticides and fungicides, even if Organic. Encourage ladybugs and beetles by creating “ladybug hotels” and “beetle banks”. (There are some photos to inspire you.)
Plant for a continuous supply of insect-attracting blooms. Yarrow, ajuga, alyssum, dill, and fennel flower early in the year and attract predators like hoverflies, ladybugs, lacewings, tachinid flies, and parasitic wasps. Also grow early blooming flowers with pollen and nectar predators can use as alternative foods – borage is fast at producing nectar, as are dandelions. Phacelia is a very attractive to predators, especially aphid predators like hoverflies and parasitic wasps. Sow in the fall for early spring blooms. Angelica is a biennial that can flower in the spring of its second year. If you decide to trust to weeds to feed your beneficial insects, take care about how much seed they sow! This is a risk I do not recommend taking, especially in warm climates with rapid rates of growth.
In the section on crop rotations, polyculture and continuous cropping, Sally reports that she has moved away from a rigid crop rotation for many crops, following Elaine Ingham’s observation that nature does not rotate. This may be a place where home gardeners and production gardeners diverge. Mixed beds with several crops work well for manual work, but less so for those with rototillers, or even those hoping to make fast progress with a scuffle hoe. Mixed plantings are attractive and fun for the solo gardener, but having others pull up your delightful medley suggests it doesn’t work so well for bigger operations.
This book is not dogmatic. Rotations help disrupt pest and disease cycles, and here you can read brief descriptions of three-crop, four-crop and eight-crop rotations. You can also devise ad-hoc rotations and grow beds of different crops next to each other, in order to benefit from diversity without slowing down your hoeing or putting a bed out of commission while you wait for the last item in that bed to finish its lifecycle.
Shumei Natural Agriculture Farm, Yatesbury, Calne, in SW England has been increasing yields year by year, with no rotation, no pesticides, and no fertilizers other than material from immediately around the beds that is incorporated into the soil. You can’t successfully switch instantly to this method of growing, because it takes time and lots of the right microbes for the soil to adapt. Charles Dowding is experimenting with this at Homeacres, his garden in Somerset. Continuous cropping is a challenging idea to those of us who came up when organics was the opposite of industrial monocropping. We championed rotations.
The author provides a list of perennial vegetables she is growing: Chinese artichokes, Jerusalem artichokes, globe artichokes, Good king henry, lovage, perennial kales, scorzonera, sea beet, sea kale, skirret, Babington leeks, potato onions, walking onions, and Welsh onions. No rotation is used for these no-dig crops, which grow with a layer of leaf litter on the soil.
Agroforestry is the practice of growing vegetables in wide alleys between trees. Sally has tried this by planting a row of cordon apples (trees trained to a single stem) along the edge of a vegetable bed. US readers should not follow her exact hedge design plan, as autumn olive, blackthorn and dog rose, for example, are invasive here.
Part 4 of the book is on boosting defenses, and how biocontrol works. This is the use of one organism to control a pest or disease. It is important to learn about the pests you have and their particular biocontrols. It’s not a case of opening the bag and throwing the stuff on! Biocontrols have specific requirements, such as temperature or moisture. Timing is important.
Parasitic wasps, minute pirate bugs and predatory mites like Phystoseilus persimilis (which eats spider mites) can be introduced for their appropriate prey. Try to save biocontrols for when you really have a problem, and make sure you correctly identify the pest you want to control.
Predatory nematodes each have their own mutualistic bacteria living in their gut. When the predatory nematode works its way into its prey, it releases its bacteria, which kill and digest the prey. Reminds me of the Trojan Horse! The process happens below ground – nothing to see here! I found this fascinating! Nematodes need a film of water to live and move in, and temperatures above 41˚F (5˚C). Buy the right nematodes (and bacteria) for each job. This book has a two-page spread on which parasitic nematode to use for which pest. I have not seen this quality of information in any other book! Nematodes can be used to manage slugs, weevils, carrot rust fly, cutworms, onion fly, gooseberry sawfly, thrips, codling moth and more.
Plants have their own protective species. The introduction to the rhizosphere (microbiome around the roots) includes fascinating details on a type of morel mushroom that farms bacteria! Soil fungi are important for most crops, except brassicas and chenopods (beets, spinach and chard). We hear about the rhizosphere, but not the phyllosphere, the equivalent collection of micro-organisms on the leaves. This is mainly, but not only, composed of bacteria. About 10 billion on one leaf, and all different from the bacteria in the soil, and varying from one crop to another! Young leaves have mostly bacteria, mature leaves have more yeasts and senescent leaves mostly filamentous fungi. These microbes protect the plant’s health, supply biofertilizers, biostimulants and biopesticides. Some leaf bacteria suppress growth in caterpillars feeding on the leaf. Understanding this helps us appreciate the reasons for not spraying plants haphazardly with things that “might help”.
Plants have an arsenal of defenses. Thorns and hairs are just the most obvious. Some plants stockpile toxins to provide fast response to insect attack, others manufacture them as needed. When attacked, many plants respond by toughening up their cell walls in the area being attacked. Plants release various volatile compounds communicating with other plants and with insects (both the pests and predators of those pests). The example given is that when corn roots are attacked by a certain larva, the roots release a compound that attracts a nematode that is a predator of that larva. Sometimes, though, the attacker wins, as when certain beetles release their own volatile compounds in response to a plant’s compounds, signaling to other beetles to join the attack. Colorado potato beetles do this. This complexity calls our interventions into question: is it helpful to handpick the pests? Not if the pests call on comrades to join the fight.
If your soil is already healthy and rich in microbes, Sally thinks additions are not needed, including biostimulants, compost teas and foliar sprays to boost the numbers of beneficial bacteria and fungi. Biofungicides can prevent particular soil-borne diseases, but can’t cure them after the fact. Biofumigation is the process of growing a particular cover crop, chopping it finely and incorporating it into the oil, taking advantage of the allelopathic compounds released, to kill pests, diseases or weed seeds. Mustards, radishes and forage sorghum all have bio-fumigant properties.
The chapter on barriers, lures, traps and sprays includes recipes, and the caution that many homemade sprays kill beneficials as well as pests, as do some of the Organic commercial sprays like neem, Spinosad, quassia. Use these only as a last resort, and pay attention to dilution rates, time of day to spray and frequency of use.
Here you can find instructions for carefully treating seeds with a disease-fighting hot water treatment before planting. You can also find cautions, such as not heat-treating peas, beans, corn, cucumbers, lettuce or beets. Or old seed, as the germination rate might deteriorate too far.
Part 5 of the book is an A-Z of Pests and Disease. First are aphids – there are so many kinds of aphids! The lifecycle of aphids starts in spring with eggs hatching into wingless females that give birth via parthenogenesis to more females. Within a week, one female can produce 100 clones, which can repeat the process at the age of one week. This continues until adverse weather or predators trigger production of a generation of winged female aphids that moves to new plants. Later in summer male aphids are born and females lay fertilized eggs that overwinter on host plants, to hatch the following spring.
Handpicking aphids is likely impossible, so start by blasting them off the plants with a water jet from a hose. This may decrease the population enough for natural predators to begin control. Failing this, a soap spray can be effective, although aphid predators will also be harmed. If you plant before any aphids arrive, you can use a fine mesh netting to keep them off, but monitor to make sure no aphids have got inside the net. You could try trap crops of nasturtiums to draw aphids away from your crop, but how much of your space do you want to devote to nasturtiums, and how do you deal with aphids then? The same choices of water and soap.
The list of pests continues through the alphabet. For some, nasturtiums can act as a repellent rather than a trap crop. Cucumber beetles are a good example. Nasturtiums are a brassica, and will attract cabbage caterpillars if there are no other brassicas around. There are two pages on making the garden inhospitable to slugs and snails and three pages of control options including beneficial nematodes, ducks, coffee grounds (acidic and non-specific) and iron phosphate pellets. Finally, there are whitefly and wireworms.
The disease chapter starts with various blights, including two pages on potato blight (both types). Cankers, club root, damping off fungi, mildews, molds, rots, rusts, spots, scabs, viruses, and on with the sad list to end with wilts. It makes sense in an organizational way to end with the problems, but it makes for a sorry place to leave off.
This book is good on detailed info on soil micro-organisms and the general theme works globally. I recommend checking against local Extension Service oreOrganic before following any of the specific techniques, to ensure it’s likely to succeed where you live.
Good tools for small-scale no-till work are hard to find. This Haraka Planter has the possibility of providing a breakthrough, so although I don’t have much experience of it, I’m spreading the information. I hope those who buy one and try it will leave a comment. [I’m not receiving any commission if you do buy one.]
The Haraka planter is a very sturdy South African punch planter made for small-scale farmers. Built in Africa for African farmers, and now also available in the US.
It is made by Eden Equipment, and is used for large seeds such as corn, beans, peas, sorghum, soybeans, sunflower. It has a set of thick plastic plates for various seed sizes. We used the smallest hole size for Kandy Korn sweet corn (a fairly small-seeded variety). That gives you some idea of which seeds it can handle. Okra would work, I feel pretty sure. If sorghum and sunflowers work, how about squash, cucumbers and melons?
It can be used on tilled or no-till plots. It can punch through crop debris and plastic mulch very effectively. [Be careful – I tried loading one into the back of a car with two flattened cardboard boxes protecting the seat. It punched right through the cardboard!] On their website there is a video and a link to a flyer. They claim it is the fastest manual planter available. It certainly makes steady progress, as you’ll see in the video. You can plant 1 hectare in 10 hours.
It does take some serious pushing – we tested it first in tilled soil and that was harder work than the soil which had not been recently tilled. See the video to understand the punching and hole-opening action of the sturdy points on the wheel.
You can add a draft animal or a second person pulling, to share the work, if very tough going. You can make and add concrete weights to improve soil penetration in situations with a lot of straw, or packed soil. You can see those in the photo below
The planter comes with an assembly manual that is fairly straight-forward. It uses black and white photos rather than diagrams, so it is a bit hard at a couple of points to determine what to do. I called in someone who already uses one to show me the two bits I was not understanding.
There is a planting mode and a traveling mode, where you flip the heavy tool over and run it on the packing wheel without engaging the planter moving punches. I was struggling to flip the tool over, but my farming friend showed me a way to flip it over sideways, rather than the end-over method I understood from the manual. Later I saw in this video one of the operators push it with his foot to start the flipping action and that was helpful.
In-row spacing: 300mm (fixed) (11.8”). You can make two passes, offset by 6” for closer spacing.)
Eden Equipment also makes a Haraka fine seeder, which I have not seen. It is made for large scale vegetable gardens and small farms, and works in cultivated soil, not for no-till. You can download their flyer from the website. There’s also a video and lots of photos. Like the punch planter, it has a large steel wheel.
Planting depth: 0-20 mm (0.8”), adjustable
Calibration method: kg/ha (no seed spacing)
Seed: grass, small grains, Lucerne (alfalfa), radish, carrot, onion, etc.
For USA sales of both planters, contact Ben Johnston in Montevallo, Birmingham AL
In this monthly series, I have chosen 14 Workhorse Crops (including two pairs) to focus on until April 2022: These are crops that we can rely on under a wide range of conditions. Some Workhorse Crops are easy to grow, some pump out lots of food, some are “insurance crops”, some are especially profitable (for those growing for market), and watermelons are simply the circus pony – we all need fun!
I hope this series will help growers become more efficient, productive and profitable (if selling) as we expand our lives again. Perhaps you don’t have as much time at home as last year, but no need to give up growing your own food, just make some smart choices of less time-consuming crops and growing methods.
In July here in central Virginia, the heat strikes hard, and the daylight has started to get a tiny bit shorter. This month we reach the peak of the year – next month we will really need to plan and execute our plans for a fall and winter garden. Most of our work in July is harvesting and weed control. In July we can plant 7 of our 14 Workhorse Crops, including the two pairs. It’s too late for asparagus, potatoes, tomatoes, watermelons, and winter squash.
July’s Last Chance Sowings – (more Last Chances in August).
We sow our last edamame 7/14 and our last sweet corn 7/16. We sow our last bush green beans 8/1-8/3, and zucchini, summer squash and cucumbers by 8/5 at the latest. If you are in a colder climate than ours, with a first frost earlier than our October 14, your last sowings of beans, zucchini, summer squash and cucumbers will be in July.
In July we still have time to sow fall crops that need 30-50 days to maturity, if we want to harvest them between mid-September and mid-October. For crops to harvest from late September to late October, we have time for those that take 30-70 days.
Beans: We sow bush beans every few weeks to keep up supplies of tender beautiful beans. See June’s Special Topic section for info about Succession Planting, to help you determine when and how often to sow beans, and how we control Mexican Bean Beetles that used to destroy our bean plantings. Our workhorse green bush bean is Provider. Bush Blue Lake comes a close second, and we often alternate them, with Provider for the 1st, 3rd, 5th sowings and Blue Lake for the 2nd and 4th. Provider is a little bit more cold-tolerant, and a little faster than Bush Blue Lake, at 50 days compared to 55.
Cabbage: Most brassicas will germinate fast at 86°F (30°C). The challenge is keeping the soil moist. For fall crops, we use an outdoor nursery seedbed and bare root transplants, because this works best for us. Having the seedlings directly in the soil “drought-proofs” them to some extent; they can form deep roots and don’t dry out so fast. Other people might prefer to sow in flats.
To avoid flea beetles and harlequin bugs, we cover the beds until the plants are big enough to stand up for themselves against “pest bullying”. We like ProtekNet insect mesh on wire hoops. Overly thick rowcover or rowcover resting directly on the plants can make the seedlings more likely to die of fungal diseases in hot weather – good airflow is vital.
We aim to transplant most brassicas at four true leaves (3-4 weeks after sowing). In hot weather, use younger transplants than you would in spring, because larger plants can wilt from high transpiration losses. If we find ourselves transplanting older plants, we remove a couple of the older leaves to reduce these losses.
We sow cabbage (and broccoli, and some Asian greens to transplant mid-late July) in June and July. August is too late for us to start those.
Carrots: After May we hope not to need to sow more until the beginning of August. We have just finished harvesting our spring carrots and have them bagged in the walk-in cooler. Carrots grown in hot weather don’t taste that good, but home-grown hot weather carrots are still better than ancient carrots from thousands of miles away. If we have not grown enough carrots by the end of May to see us through to October, we sow in June, and even July if we must. We shade the beds.
Chard: Swiss chard can be sown here in July or August, for a nice fall harvest. It germinates best at 85°F (29°C). It grows big leaves within 50 days of sowing, and smaller ones after only 35 days. Chard is not plagued by flea beetles, and does not have problems germinating in hot weather like spinach does. Chard is the poster-child insurance crop!
We use chard for fresh greens in summer, transplanted into a hay mulch in late April. Organic mulches help keep the soil cool during hot weather, so are very helpful for leafy greens. This crop will be in the ground until mid-winter, and mulch will keep back most of the weeds.
Remember, chard is biennial, and will not bolt the first year (unless stressed by lack of water). I’ve noticed the red chards bolt more easily than the green ones. I suppose red crops are a bit stressed already, as they are short of chlorophyll, compared to the green ones, making photosynthesis harder work.
To calculate the last worthwhile sowing date, add the number of days to maturity and the length of the harvest window (7-14 days), and subtract this number from your average first frost date. For our 10/14 frost date, using an 80-day corn as an example, 80+7=87 days, brings us back to July 19 for our final sowing date. In practice, because corn matures faster in summer than in spring, this calculation gives you a little wiggle room in case the first frost is earlier than average. You could add a little more wiggle-room to be more sure. We make our last sowing on July 16, when there are not enough warm days left in the season to mature another sowing.
Kale and collards We sow 6 beds of kale, two each, every 6 days, (8/4, 8/10, 8/16, 8/24) until we succeed in getting enough established. Often we’ll get patchy emergence and end up transplanting plants from one bed or one end of a bed to fill out the blank areas. If your climate is a colder zone than ours, you will be sowing kale and collards in July.
Zucchini (courgettes) and summer squash: another crop type that we succession sow, to get a continuous supply. We make five or six plantings, each one half yellow squash (Zephyr, Gentry) and half zucchini (TenderGrey, Noche, Golden Glory). Now the soil is warm (60°F/15.5°C), we direct sow. The time from sowing to harvest is only around 42-54 days. 8/5 is our last sowing date for zucchini, summer squash and cucumbers. We like Noche zucchini for a disease-resistant zucchini variety (diseases are worse here later in summer).
After sowing, we hoop and cover the row with insect netting (rowcover works if it has no big holes). We have many bugs that like these plants, especially the striped cucumber beetles, so we keep the rows covered until female flowers appear. At that point we need the service of the pollinators, unless the squash is parthenocarpic (sets fruit without pollination). We pack away the covers, hoe and thin the squash to 24” (60 cm). It would be better to thin sooner, but we rarely find the time.
Workhorse Crops to Harvest in July
Nine of our 14 workhorses can be harvested in July
Beans from early July/late June,
Cabbage is ready here from late May until mid-July. We store enough to feed us until we start harvesting fall cabbage. For cabbage to store to eat over the summer, cut with a strong knife and set it upside down on the nest of leaves to dry a little. Come back along the row with a net or plastic bag and gather up the storage quality cabbages to refrigerate.
Sweet corn: Harvest before daybreak for best flavor, because the sugars manufactured in the plant the day before become concentrated during the night. We’re not that dedicated. We harvest ours in the morning, and hurry it to the walk-in cooler.
Harvest may start 18-24 days after half the ear silks show, if the weather has been reasonably warm. Judging corn’s ripeness is a skill, based on information from many of the senses. The first sign we look for is brown dead silks. If the ear has passed that test, we investigate further. All ears should look and feel plump and rounded to the tip. Each variety is a little different, so close attention is needed. Some varieties exhibit “flagging” of the ear, meaning it leans away from the stalk as it matures and gets heavier. New crew can test for ripeness by opening the side of the husk with thumb nails, and puncturing a kernel: the kernels should look filled-out and squarish, not round and pearly; the juice should be milky, not watery or doughy. The advantage of opening the side of the husks is that it is possible to close the gap if the ear is not ripe, without risk of collecting dew or rainfall. If the ear is ripe, we bend it downwards, give it a quarter-turn twist, and then pull up away from the plant.
We harvest every other day, which balances getting the amount we need with not spending more time than needed picking. Such a schedule can work well for CSA farms. Other growers could well need to harvest every day, if daily fresh corn is what your market needs. Leaving a three-day gap risks poor quality starchy ears and a lower total yield.
Take steps to keep the crop cool while harvesting. Never leave buckets of corn out in the sun. Even at room temperature, harvested OP ears lose half their sweetness in 24 hours.
After harvest, cool the corn quickly. Hydrocool if you have a large operation: drench or immerse the crop in near-freezing water. Otherwise, simply refrigerate and keep the corn cool until it reaches the consumer.
Carrots perhaps, although we do intend to get all our spring carrots harvested and stored before the weather gets very hot.
Chard can be harvested whenever you want some. Simply snap or cut off some outer leaves and stand them in a bucket with a little water until you cook them. For sustainable harvesting levels, we use the standard leafy green mnemonic “8 for later” meaning that we make sure to leave at least eight of the inner leaves on each plant, as we harvest the outer leaves. With chard, we can take a couple more than this, but we don’t want to exhaust our workhorses!
Garlic in the north might get harvested in July, but here in the mid-Atlantic ours has been curing for several weeks and is now ready for snipping, sorting and storing. I wrote about garlic recently. Several people have written to ask about the nylon netting in our photos in those posts. We don’t remember where we got it. The sides of the squares/diamonds are about 1.5”. A reader sent this photo and she is using Tenax fencing. It’s sold for deer fencing and is very strong.
Potatoes, if planted in March, will be ready to harvest this month. If the tops have died, dig up a few samples and see if the skins rub off, or if they have thickened up enough for storage. It’s fine to dig some for immediate use, but for long-term storage, they need thick skins. This usually takes two weeks after the tops die. You can hurry up the process by mowing the tops to bring growth to an end. Then wait two weeks and test them. I wrote about potato harvest last year.
Tomatoes are ready to harvest outdoors now. Wait for the leaves to dry from rain or dew, before touching the plants. To minimize the spread of fungal diseases. Lightly press the bottom of the tomato to make sure it is soft enough to be fully ripe. Snap the tomato off at the knuckle, so that the plant gets the signal the fruit has gone, and will ripen more.
Zucchini and summer squash in our climate need harvesting every day, if we are going to avoid blimps. Summer squash can be twisted off the plants, but zucchini need to be cut. The hairs on the leaves, combined with sweat, can cause unpleasant itchiness. Wear long sleeves or make special sleeves for this job that are not attached to any particular shirt. Make a casing and insert elastic around the top edge (and the bottom, if there are no cuffs). These sleeves can be bought, but everyone probably has an old shirt and could make their own.
We harvest every day to the fall frost (or beyond if we remember to cover that last planting with rowcover on chilly nights.).
Having determined there is a hornworm in the vicinity, the next task is to find it. They can grow to be 4″ caterpillars. You’d think it would be easy – a big striped caterpillar like that. Not so! They are the exact same shade of green as tomato leaves. Hornworms can look remarkably similar to curled tomato leaves. The white stripes mimic the veins on the undersides of the leaves.
When I find some signs, I gaze at the area, looking for discrepancies in the pattern – bare stems with lumps on them. Usually the caterpillar is on the underside of a chewed stem, and often (but not always) they have their heads raised. When you find one, get a firm grip, pull it off the plant (they have strong legs which hold on tight), drop it on the ground and stomp on it. The skins are quite thick.
If I still can’t see the worm, I stand still and sway a bit from side to side, viewing the plant from different perspectives. It helps if the top of the plant is back-lit, but I do always check both sides of the row, no matter where the sun is. Knowing the signs of hornworm grazing can save you time looking everywhere. Focus your attention on where you are most likely to find them, and you will get the most success in the least time.
String-weaving (also known as basket-weaving or Florida string weaving) is an easy way to support lots of tomato plants. This method is ideal for long rows,. All you have to store over the winter are the stakes. No bulky cages or rolls of wire mesh. We have used it for all kinds of tomatoes, and some other crops.
String-weaving comes equal-best or second best in almost all categories: yield, earliness, fruit size, quality, pest control and protection from sunburn. It is worst as far as labor cost, although it doesn’t seem so bad, as the labor is spread out through the season. Trellising with a high wire between posts, and strings to wind each plant around, comes out best for earliness, fruit size and pest control (but worst for cracking, and thus not so good for marketable yield). Cages are best for marketable yield (so people who only grow relatively few plants could choose that method). But caged tomatoes do poorly on earliness and fruit size. The cheapest support system is none at all – sprawing the plants on the ground. But the fruit quality and quantity is poor, (pests, rotting, cracking and sunburn reduce potential yields).
Tools for string weaving
Put tomato stakes in soon after planting, while the soil is still soft, and you can see where the drip tape is. We use 6’ (1.8 m) metal T-posts. Some people put an extra stake at an angle tied to the end stakes as a brace. Set one T-post after every two plants along the row. Our stringing tool made is a 2’ (30 cm) length of wood, with a hole drilled through near each end. Twine is threaded through one hole and back out the other. A length of plastic pipe could also be used (pipe doesn’t need holes drilled, as the twine can be threaded down through the pipe). The twine moves through the tool freely. The tool serves as an extension of the worker’s arm, to get the twine over tall stakes, and you can give it a quarter turn to pull the twine tight. For maximum efficiency, keep the tool in your hand all the time.
Our variation on string-weaving looks quite like the drawing from the Extension Service. We have a couple of tweaks that make string-weaving work even better. Our first trick is to park the bale of twine in a bucket at the beginning of the row and leave it there. No need to lug it with you! Stand between the working end of the twine and the slack being pulled out of the bucket – get yourself inside the loop when you start, to avoid tangles. The spare twine will be running out behind you as you work the first side of the row. You’ll use it for the return journey.
Tomato string-weaving step-by-step:
When the plants are 12” (30cm) tall, tie the twine onto an end stake, about 8-10” (20-25 cm) above the ground.
Pass the twine in front of two plants and the next stake and wrap the twine around the back of the stake, pull it tight, and twist the tool to help tighten it.
Next, here’s our second trick: use the thumb or forefinger of your other (non-tool-holding) hand on the crossover to keep it tight, and loop the twine around the stake again, making sure that the second loop ends up below the first. This locks the twine so that if you let go, or later on a groundhog chews through your twine, the whole row doesn’t slacken.
Continue along the row to the end, then take the tool round to the other side wrapping the twine round the end post.
Weave back along the other side of the same row, putting a row of twine at the same level as on the first side. You will need to flip the twine that was behind you on the first side over to your new working side as you need it. Once you reach the end, tie off the twine and cut it.
Close view of coming back on the second side of string-weaving.
Photo Kathryn Simmons
You’ll see that you never actually wrap twine around a tomato plant, so there no injury from tight twine. The plants are simply held between two fences of twine that you “build” by making a new round once-a-week as the plants grow (every 8” (20 cm) up the stakes).
At the end of the season, cut the twine each side of each post, and pull it out, then remove the stakes and till in the tomato plants.
Pawpaws: The Complete Growing and Marketing Guide by Blake Cothron, New Society Publishers, 2021, $29.99
“Blake Cothron is an authority on pawpaws, and provides a clear, detailed guide for commercial success in growing this “oddly appealing species” (his own words). The supply of this exotic, trending, easy-to-grow fruit has not yet met the demand. Blake shares the wealth of his knowledge, including challenges, and when he doesn’t know, he says so (and it’s probable that others don’t know either.)”
This is the advance praise I wrote for Pawpaws, now inside the front cover. Last fall I reviewed Michael Judd’sFor the Love of Pawpaws, a permaculturist’s take on growing pawpaws among diversified crops. Blake’s book, while mainly intended for small-scale organic commercial growers, is equally useful for the backyard enthusiast. Blake ensures you have the information you need to choose what to grow, where to buy it, how to plant it, keep it thriving, prune and harvest. Depending on your scale, you can try the nine exquisite recipes here, or sell gourmet pawpaws online, or make value-added products such as craft brews, jams, and baked goods.
Blake and his wife Rachel Cothron, own Peaceful Heritage Nursery, a 4-acre USDA Certified Organic research farm, orchard, and edible plant nursery, near Louisville, Kentucky, the perfect climate for pawpaws.
America’s almost forgotten native fruit looks tropical and has an exotic appeal, but is an easy to grow temperate climate tree, and very cold hardy (US Winter hardiness zone 5, -20˚F/-29˚C). It is ripe for 4-6 weeks in late August-September. Although mostly grown in the South-east and Mid-Atlantic, pawpaws will grow in portions of 26 US states. Avoid confusion with the tropical papaya, which is sometimes also called pawpaw. The North American pawpaw is Asimina triloba.
The book is studded with cultural gems such as that you can sometimes locate the site of an old native American village by the clusters of pawpaws still growing there.
There are some false myths about pawpaws, including the idea that they are secretly tropical and related to bananas, papaya and mango, They are not. The second myth is that they grow best in shade. Also not true! They can grow in shade, but will not produce good fruit unless in full sun. A third myth is that they are ripe when blackened by frost. Oh no! They are usually ripe weeks before frost. Frost is not a benefit, but a cause of damage! (This myth is not true of persimmons either.) Another myth is that the flowers smell really bad. It’s just not true. Lastly, a myth that would be nice if true: pawpaws are not immune to all diseases and pests. Certainly they don’t suffer from as many health challenges as apples or peaches, but there are pawpaw troubles as Blake explains. All these stories show how important it is to have a trustworthy guidebook.
Wild pawpaws are found as thickets of suckers growing up from the enmeshed roots of older trees, or as clusters of seedlings around a mother tree. They may feed wild animals, but will not grow the large tasty fruits humans want. Suckers are clones of the mother tree, and as pawpaws are rarely self-fertile, these thickets do not produce fruit. For human food, pawpaw trees need full sun, well-draining soil and plenty of space. Not what you might have assumed. Read this book!
Wild pawpaws are most often found in moist lowland areas near water, but in well-draining areas, not swampland. They are often on sunny slopes (not northerly sides). They can be found along edges of clearings, trails and old roadways. In Kentucky, Blake reports about 25% of the wild pawpaws are tasty, 50% are edible and 25% are “spitters”. If you’ve experienced anything other than the top 25%, this book can be your encouragement to try some cultivated types.
When you buy pawpaw trees, go for potted 1-4ft grafted trees at $30-$50 each. These will survive for 15-20 years and provide harvests for 10-15 of those. During that time you can plan where and when to plant your next pawpaw grove. Cheap bare-root seedling trees will save you money, but they won’t earn you money or appreciative friends. Premium fruit comes from premium trees, well cared-for.
Pawpaw trees can mature at 20ft tall, or you can keep them pruned to be 7-15ft and avoid high ladder work. The diameter of a mature tree can be 20ft in full sun, with an attractive pyramid shape.
When planning your orchard site, remember “the more sun, the more fruit”. 12-14 hours is best, but 7-8 hours of direct, strong, undiluted sunlight will be enough for a decent fruit set. Pawpaws are not too exacting about soil, apart from the need for good drainage. Soil can be improved, but heavy wet soils need improving years before planting!
If you plan to mow with a tractor, you’ll need to plant rows 18-20ft apart. Otherwise 15-18ft between rows and 8-12ft between trees in the row will be enough. You do need genetically different trees close enough to cross-pollinate.
There are three colors of fruit: yellow, orange and white, with the orange ones having the strongest flavors (“banana/honey/persimmon/pumpkin”). Yellow-fleshed cultivars have more of a “banana/cocoa butter/Mexican flan/nutty/marshmallow/caramel flavor”, very sweet, with an aroma of citrus, pineapple, cantaloupe and strawberry. The white-fleshed ones are the mildest, with a “vanilla/light banana/cantaloupe/coconut/tropical fruit” flavor and a high sugar content.
Pawpaw fruit should be creamy, not watery or hard. There should not be any bitter or unpleasant after-taste! Another feature to consider when choosing varieties is the seed-to-pulp ratio. Ideally the seeds will comprise less than 10% of the total weight. Wild pawpaws can be 50% to 75% seeds.
Blake includes 57 pages of good, bad and interesting facets of all 50 cultivars he could find in 2020. Some are widely available, others need to be tracked down through the North American Pawpaw Growers Association (NAPGA) or the North American Fruit Explorers (NAFEX). Don’t rely on nursery descriptions, but use Blake’s notes, where he has worked hard to be fair and objective. This book costs less than one tree, and can save many mistakes!
Blake distinguishes between Early Ripening (Aug 20-Sept 5), Mid-Season (Sept 5-30) and Late Season (after Oct 1). The dates are for zones 5b-6b, and outside that area they offer a relative idea. There is a grading scale (incorporating different professional opinions) based on size, flavor, texture, reliability and yield. Choose As and Bs unless you have a good reason to do otherwise. Size grades are Jumbo (16oz+), Large (12-16oz), Medium (7-12oz) and Small (3-6oz). Commercial growers don’t mess with the little ones.
A matter to face with pawpaws is that eating under-ripe ones can cause nausea. Some people cannot tolerate cooked pawpaw, Some speculate that it is the combination of cooked pawpaw with grains (as in baked goods) that give them trouble. Be ready for these possibilities but do not let them discourage you (or potential customers!) There are also people who sometimes experience mild euphoria after eating pawpaws, without harm. The one thing to never make or consume, is pawpaw fruit leather! It can cause 24 hours of serious intestinal distress. This is the “warts and all” part of the book. Avoid these problems and enjoy everything else about pawpaws.
Thinking how to incorporate pawpaws into your diverse farming? You do need to keep the grass and weeds down somehow. Grazing, mowing or mulching are the usual methods. In damp eastern regions, mowing will need to be done once a month from April to October. Mulch needs to follow the 3:3:3 rule: 3ins deep, 3ft wide around each tree, keeping 3ins away from the trunk. Cardboard topped with organic mulch is one option. Landscape fabric is another. Wood or bark chips can work well.
Blake tells cautionary tales about planting a new pawpaw orchard and not providing irrigation. Climate change is making rainfall more erratic and we get both extremes of quantity. There is no substitute for water in a drought, so install an irrigation system before you plant, or immediately afterwards. Once the orchard is established, you might not need to water much. Blake recommends orchard tubing with two emitters per tree, providing a gallon of water per tree per day.
Pawpaws go dormant in winter, unlike some other fruits that can be planted in the fall in milder climates. Plant in spring or early summer, digging large holes, breaking up the edges of the hole, supplying amendments, and having mulch on hand. This book gives clear step-by-step instructions. Staked tree protectors are essential for trees shorter than 30ins (seedlings) or 18ins (grafted trees). One main purpose is to protect the young trees from UV radiation. Tubex and Blue-X tree shelters are suggested.
While the trees are young, you can use the aisles for something else, such as grazing, or growing hay or another crop. Whichever weed control method you use, you will need to hand weed the small inner circles around each tree, including clipping suckers coming up from the rootstock. This gives you an opportunity to study each tree up close and see how it’s doing.
The pests and diseases chapter is complemented by color photos. With pawpaws, there is still much that is not known (or was known and then lost). Insects that attack pawpaws do not usually do much damage, although the list is long and includes borers, stinging caterpillars, a webworm, a leaf roller, the ubiquitous Japanese beetle, slugs, snails aphids, mites, thrips, scale insects and the Zebra Swallowtail Butterfly. Jeremy Lowe at VSU has a very good PowerPoint presentation with superb photos.
I have been fascinated by the ZSB since reading about it in Michael Judd’s book, where I learned that the butterflies arrive at the time the pawpaws flower. Since then, I’m on the lookout each spring. The pawpaw is the ZSB’s only host, so do not kill all their caterpillars in your pawpaw trees – they have nowhere else to live! The eggs are laid between June and August. The caterpillars, which grow to 2ins long, eat the leaves and the damage to young trees is a real concern. Blake recommends hand-picking the caterpillars and carrying them to a wild pawpaw patch, or to some mature cultivated pawpaws, where they do little damage. Also, avoid destroying nearby wasp nests as the Ichneumon wasp Trogus pennator is a predator of the caterpillars, and nature may balance out.
For many pests and diseases, the key to healthy trees is good sanitation, keeping a clean orchard floor (mulched or mowed, I don’t mean bare soil!), and removing diseased wood or leaves.
Deer bite off buds and young shoots, and rub their antlers on the trunks. Goats do not eat pawpaw trees, although they can do damage rubbing their horns against the trunks. Other large pests include raccoons, possums, small rodents, and sapsuckers (small woodpeckers).
Diseases include Phyllosticta leaf spot, a fungal pathogen., and a few others, including Black Spot (Diplocarpon spp) which strikes in rainy seasons.
The condition of the leaves will show you if your fertility program is adequate. Healthy leaves are a deep vibrant green and bigger than human hands. Young trees should make 16-24ins of growth each year after the first one, until they are mature. Fertilize heavily from March-June in zone 6.
The chapter on flowering stages and cold tolerance of each (information that is hard to find elsewhere) will save you from disappointment. See the helpful photos showing blossom stages. Unlike some tree fruits (apples, pears), pawpaws bloom over a period of time, resulting in flowers at different stages, giving insurance against all being killed by one frost. In zone 6 the very cold-hardy Velvet Bud stage, when fruit buds start to develop, is in mid-February and full bloom starts in early April.
Pollination is conducted by various flies, beetles including lady bugs and ants, and spiders. Not by bees. So for good pollination, plant insect-attracting flowers in your orchard. Fruit takes 4-7 months to mature.
Pawpaw trees begin to fruit in year 3-5, with 5-10lbs/tree and double that the next year. A mature tree will yield a bushel (30-40lbs). Harvesting needs to be done gently (no vigorous tree-shaking!). Use sharp bypass pruners and set the fruit in a single layer in cushioned boxes. Ship immediately or use refrigerated storage for a couple of days. If picked ripe but firm, pawpaws can be stored for 3-4 weeks under refrigeration. They won’t be as delicious as tree-ripened fruits.
You can sell pawpaws at 2-3 times the price of apples, maybe $5-10/lb. Because the demand is not widespread, do not rely on farmers’ markets. The marketing chapter suggests 8 channels for selling pawpaw fruit. You will need to provide information and an attractive display or stunning photos if selling online. Avoid the question “What do we do now with a hundred or even thousands of pounds of soft, dripping ripe pawpaw fruit?” by planning months or years ahead.
If selling remotely, make it really clear that pawpaws are only available to ship in August and September (or whatever is true in your region). Ship out only perfect unblemished fruit picked that same day, and ship only Monday-Thursday. Weekend shipping can go very wrong! Pack the fruit with enough lightweight packing material so that when you shake the box, nothing moves. (I learned this tip packing garlic for shipping.) Shipping fruit across the country is a strange business with a large carbon footprint. Consider if you have better options selling locally, including specialty groceries.
Sales to restaurants can work well, as long as you have clear agreements, including price ($1-$3 per pound). Be perfectly reliable, make the chef’s life as easy as possible. Deliver early rather than late if you can’t be on time.
One feature of modern pawpaw marketing is that currently most Americans prefer crunchy fruit (even crunchy peaches) and the pawpaw is far from crunchy. Describing the texture as similar to creamy avocados, but sweet, seems a promising approach.
You could sell fruit as frozen pulp (deseeded!) to restaurants, bakeries or breweries. You could make value-added products from the less-than-perfect fruit yourself. As well as the items mentioned earlier, don’t overlook the possibilities of ice cream, chutney, food supplement pills and jewelry made form pawpaw seeds. Find out about the Cottage Food Laws in your state. Blake recommends the Ohio Pawpaw Growers Association with 29 handouts about NA Pawpaws.
Aside from selling fruit, you could sell seeds, seedlings or grafted potted trees. Seedling trees can be unpredictable, but if you start with good parents, you improve the chance of getting good seedlings. You can use seedlings as rootstock for grafting, or sell them to people growing food forests where productivity is not the main concern.
Seeds removed from ripe fruits need to be washed, cleaned, sterilized, labeled, stratified at 35-45˚F for 90-120 days, ensuring they don’t freeze. Seeds are sown on their sides, and can take 6-12 weeks to emerge above the soil. 2-3 year-old seedlings are used for grafting rootstock. Grafting is fairly easy, and KSU has some very good free videos.
The book includes a pawpaw calendar, cost analysis and some troubleshooting. Tips include not to worry if your new trees only grow a few inches the first year. This is probably because growth is happening underground, establishing strong roots. It could be a sign of root damage during transplanting, so if you are about to plant more, improve your technique! Damage caused by sunburn, dehydration, nutritional shortages, attacks by beetles, sapsuckers, string-trimmers, Phyllosticta disease, borers, deer, and winter sun, are all covered.
The cost analysis deals with start-up costs (not minor when trees cost $30 each). For an acre containing 295 trees that’s $8,850. Tree protection fencing can add $1,376. Landscape fabric and irrigation together can equal the fencing cost. Other smaller costs add in to a total close to $10, 700 for the acre. Try for a wholesale tree price between $15 and $25, and your total is more like $6,260.
Production costs are estimated by KSU at $1,650/acre; harvest and market costs at $6,200/acre, including labor for pruning and harvesting at $12.50/hr. Total variable costs come out at $8,400/acre. Gross returns could be $9,600/acre, if you sell wholesale at $1.75/pound. Don’t quit your day job yet, but pawpaws can be a good addition to an existing operation with compatible markets.
The two-page Pawpaw Orchard Calendar is a quick reference guide for annual maintenance, and the dates where you live may need to be as much as one month later in spring and one month earlier in fall. The resources section includes books, supplies, and groups, including Peaceful Heritage Nursery.
Blake has created a highly readable, enjoyable and very intensive exploration into the cultivation of North American pawpaw.” This book is practical, useful and fascinating.