Okra is a long season crop, so cultivation or mulch to keep weeds down will be needed. We hoe until hot weather arrives and then mulch with spoiled hay (avoid using organic mulches earlier in the season, as they keep the soil cool and delay the harvest). During the rest of the growing season, the okra bed becomes a useful repository for any undiseased mulch-like materials from other beds, even quite large plants like sunflowers.
Okra has a great ability to withstand drought compared to other vegetables, but for good growth and production, you’ll need to water at least 1” (2.5 cm) a week. If there is an extended dry period and you can’t water everything, okra will be the last to suffer.
See Okra Planting Time for info on varieties, crop requirements, yield, sowing, transplanting, intercropping, and Chris Smith’s wonderful book The Whole Okra. However, if you haven’t sown your okra seed yet, time is of the essence. Okra needs 55-60 days of hot weather to produce the crop. If you are in the deep South, go ahead!
Black plastic mulch, rowcovers and transplanting can all help get the crop going earlier, as can growing in a hoophouse or caterpillar tunnel, if you are a real fan of okra. The yield per area is low, so this would be an unusual choice for the prime real estate offered by a hoophouse!
In Sweet corn, potatoes and okra, I reported that we started harvesting our okra that year a little later than it might have been because we had to replant. The first planting had leggy seedlings due to not enough light soon enough in their lives. Then we transplanted replacements with novice helpers, and they didn’t plant them deep enough. The feeble stems couldn’t take it. We made an attempt to hill them up to give more protection to the stems. Another mistake we made was over-watering. When we pulled up some of the dead plants for our postmortem, they reminded me of retted flax stems – the fibers were still there, with the soft tissue rotted away.
Succession Planting and Renovating Okra Plants
Generally only one planting of okra is made each year, although it is possible to sow in spring and fall in hot climates, using a fast-maturing variety for the later sowing. Or sow only in the summer for a fall crop, and don’t fight cold spring soil temperatures.
In hot climates, okra plants benefit from being rejuvenated in the middle of the summer, by cutting them back (with a machete, or tree loppers) to 6” (15 cm) stubs after the first heavy harvest (perhaps in the fifth week of harvesting) and after market prices start to decline. For large areas, use a tractor mower.
The plants will produce again in the fall, when prices have risen again, and fall yields can be higher than spring crops. Side-dressing at this stage can also boost production. As well as revitalizing the productivity, this process keeps the plants at a manageable height.
Alternatively, to avoid losing all your crop at once, lop progressively along the row, perhaps cutting 5% of the plants each day, starting after they reach shoulder height. Other growers tell of cutting back plants to a height of 4’ (1.2 m), which causes the plant to branch more.
Okra is about the easiest vegetable to fit into a rotation as you are unlikely to have any other mallow-family crops to worry about, and you are unlikely to be growing a huge amount. Cotton, hibiscus and the fiber plant kenaf are also in the mallow family, but do not cross-pollinate with okra.
Pests and Diseases
Okra has few serious pests or diseases, if the weather is warm. In cool weather, stressed okra plants may suffer from verticillium and fusarium wilts, soil-borne diseases that cause plants to wilt and die. Fight soil-borne diseases by avoiding soil splashing onto the plants – use drip irrigation and mulch. Foliage blights may occur, but generally they do not reach serious levels. Blossom blight can be a problem in long rainy periods.
Old varieties of okra tend to have deeper root systems and are more tolerant of root-knot nematode, to which okra is very susceptible. If you have nematodes, choose heirloom varieties. Okra will do fine after grains, such as sweet corn, or following a winter rye cover crop.
Insect pests may include Japanese beetles, stink bugs, aphids, corn earworms, flea beetles, blister beetles and cucumber beetles. You may see ants climbing the plants to drink nectar but they don’t seem to cause damage. Grasshoppers may strip the leaves in late summer in bad grasshopper years.
3-9 days after flowering pods will be mature (it takes 40 days from flowering to mature seed).
For maximum yields it is important to harvest at least every second day. If pods are missed, they will mature and limit the future flowering and therefore the yield.
We harvest six days a week, using pruners, or a small serrated knife. The stems are quite tough. Some people find their skin is irritated by the spiny leaves and like to wear long sleeves when harvesting. We cut Cow Horn at 5” (13 cm) or bigger. Some years we have attached a piece of card to special pruners for the job, showing the size to cut. Do not make assumptions about toughness without testing with a thumbnail, or snapping off the tip. We’ve also been surprised to find it necessary to show new people the difference between a rounded “empty” pointed flower bud, and an angular firm pod.
Our harvest starts in mid-July and runs until frost, a period of 12 weeks or so. At the end of the season, we find we need to dig out the massive trunks and consign them to a spot on the edge of the woods that we call “The End of the World.”
Okra does not like to be chilled! Here we need to deal with the American tendency to store almost everything in the fridge. Chilling injury of okra causes dark damp spots on the pods, which lead to pitting and slimy breakdown. Okra can be stored at 45-50°F (14-15°C) in unperforated plastic bags for up to 15 days. This compares favorably with only 2 days without a bag, or 7 days in a perforated bag. The plastic bags keep the humidity high.
Okra is very tasty pickled – if you have high yields, time to do the pickling, and a demand for off-season value-added products, go for it.
Saving seed from okra for your own use is a simple matter if you are only growing one variety. We have saved seed by decorating chosen plants with colored plastic surveying tape, like tinsel on a Christmas tree. Then we don’t pick from those plants for eating. We wait until the pods are big and dry, then harvest them before they split and shed their seeds, and put them in bags or cardboard boxes indoors to dry further and until we have time to deal with them. Mature okra seeds are greenish black. For small quantities, just twist the pods and break them open over a container of some sort. Seeds can be screened out of the mixture and/or winnowed. Empty pods make good weed-free mulch.
Okra is outcrossing but can self-pollinate. Okra varieties need to be isolated from each other by 1/8 mile (200 m) for home use, or ¼-½ mile (400-800 m) or greater for seed for sale. A plant population of 10-20 plants is needed for genetic diversity, and more than 20 plants is better for seed for commercial sale. It takes 30-50 pods to provide one pound of seed (66-110/kg).
This is another post in my new monthly series, about small fruits that can be grown sustainably in a mid-Atlantic climate. I cover planting, pruning, harvesting and care of the plants, according to the season. I’ll give links to useful publications. We have a focus fruit, and then more about others that need attention during the month. We do grow apples and pears, and some other tree fruit, but I’m not writing about those as I don’t have much recent experience.
Melons are the focus fruit for July
July is the month in our climate, to start harvesting muskmelons (often called cantaloupes), Asian melons, and canary melons. Next month I’ll talk about watermelons, which are slower to ripen.
Melons love warm, sunny days and need 80-100 days from seed sowing to harvest. For good production, melons warm weather, along with a steady supply of water. Melon plants also need good air circulation, so leaves and fruit can dry fairly quickly after dew or rainfall. To help prevent the spread of diseases, rotate crops and avoid growing them where other cucurbits were planted in the previous year or two.
Melons thrive in well-drained soil, sandy loam, or in clay soils that have been good levels of organic matter. Soil pH should be 6-6.5 for healthy melons and a good yields. Encourage drought-resilient crops by using drip irrigation, so that roots grow deep.
Types of melons
Fastest to produce a crop are the 65-day Asian melons such as Torpedo (replaced Sun Jewel), or Early Silver Line. These 1-2lb (0.5-1kg) oblong melons have refreshing crisp white flesh and are mildly sweet. Some people disparage them as “cucumber melons,” but their good points are earliness, tolerance of chilly weather, being easy to grow and having a pleasant flavor.
Muskmelon (Cucumis melo reticulatus, commonly, but inaccurately called cantaloupe) is the melon type I have most experience with. They have a yellowish-buff skin with a raised netting, and sometimes lengthwise sutures (ribbing). The flesh is orange with a complex sweet aromatic flavor, and the 3–7 lbs (1.5–3 kg) fruits take 75-84 days to mature. We have enjoyed Pike, Kansas, Delicious 51, Edisto 47 and Hales Best. My long-time favorite was Ambrosia from Seminis Seeds, but when Seminis was bought by Monsanto, I stopped growing it, as I don’t want to support Monsanto in producing GMOs. For Downy mildew resistance and tolerance to cucumber beetles, grow Trifecta from Southern Exposure Seed Exchange
True cantaloupes, Cucumis melo cantalupensis, are rarer in the US. They are rough and warty rather than netted. Prescott Fond Blanc and Petit Gris de Rennes are true cantaloupes, as are charentais melons. Charentais melons are smaller, round, good-flavored orange-fleshed melons. I have successfully grown 78-day Savor, a 2lb (0.9kg) melon with a green-grey skin and deep orange flesh.
Canary melons are smooth yellow 4lb (1.8kg) fruits with white flesh and are quite sweet.75 days to maturity. We have had good success with Mayor.
Crenshaw melons are large oblong 78-day melons with light yellow skin and very aromatic pale creamy orange flesh.
Galia tropical melons have green flesh, yellow-tan skins and a round shape. Honeydew melons are fast-maturing, smooth skinned oval melons, usually with pale-green flesh, although Honey Orange is salmon-colored. 3lbs (1.4kg), 74 days.
We tried some smaller (individual serving) melons, Tasty Bites. personal-size melons (they top out at 3lbs/1.4kg) and Sugar Cube 2–2 1/2 lb (1kg). The advantage of having a smaller fruit was not more than the disadvantage of harvesting smaller fruits.
Sowing melon seeds
Melons are a bit finicky in their youth, but given a strong start, they can do very well. You can sow melon seeds directly in the garden, but the seeds need soil temperatures of 59°F (15°C) minimum to germinate, and their best temperature is 86°F (30°C). At that temperature they only take 3 days to emerge. More and earlier success comes with sowing melon seeds indoors, where the right temperatures can happen earlier in the year. Maximum germination temperature is 100°F (38°C).
Up to three weeks before your average last frost date, sow 2 or 3 melon seeds in potting compost at a depth of ½” (1cm) in 3” (7.6cm) pots or plug flats. We are in zone 7a, with an approximate last frost date of April 25 – we sow April 15 for May 6 transplanting (21 days after sowing). After germination, the temperature should be reduced to 75°F (24°C). We always ensure our melons get a spot in the greenhouse with very good light and no drafts.
Keep the soil moist and when seedlings have reached 2” (5cm) in height, snip off the weakest ones at soil level, leaving one strong seedling per pot or cell. When the first true leaves appear, lower the temperature to 65°F (18°C) and reduce watering a little.
Harden off the transplants for a week before you set them into the garden. Set them outside in a shady area on warm days, gradually increasing the time outside each day from one hour to two hours, to three, and so on. Alternatively, use shadecloth and increase the sun exposure by an hour a day. Reduce watering a bit, to slow plant growth. Check your local weather forecast to ensure that your melon plants will not be subjected to chilly, windy conditions when they are young.
Before starting transplanting, check the soil temperature: garden soil should be at least 70°F (21°C) for melon survival. Melon plants exposed to temperatures cooler than recommended might not set fruit later on. One way to speed up soil warming is to cover the area with black plastic mulch for 1-3 weeks prior. Cut an x-shaped slit where for each plant and hold the edges of the plastic down with rocks. We space our melons at 2’ (60cm) apart in the row, with rows 6’ (2m) apart.
Melons are admittedly delicate to transplant. When outdoor conditions, soil temperature, and timing are right for transplanting melons, take great care in handling the plants. To help reduce transplant shock, water the flat (or pots) well before transplanting and avoid disturbing the roots when transplanting into the garden. Plant the entire stem in the ground, leaving only the seed leaves upwards exposed. The stems are fragile, and will do better protected in the ground. Water the soil thoroughly. If you are not using black plastic, spread organic mulch (straw, spoiled hay or dry tree leaves) around the melon vines. You might rather hoe and wait until hot weather to spread organic mulch, as this will keep the soil cool, and as I stressed already, melons like heat. Depending on soil fertility, you may want to add fish emulsion to encourage growth.
If the weather is less warm than you hoped, use hoops and thick rowcover until you are more confidant in the temperatures, then switch to netting. We hoop and net our melons immediately after transplanting, to keep the bugs off. We keep the netting on until we see female flowers (they have miniature melons between the flower and the plant). Melons require pollination, so it is necessary to remove the netting.
Care of melon plants
If weeds emerge through the mulch, pull them slowly, while stepping next to the melon stem. Melon roots near the surface can easily be injured. As melons ripen, put a piece of cardboard under the fruit to help prevent rot. With the late summer planting, you can pinch off new flowers to steer the plant’s energy into fruit that has already set. Keep the soil around melons watered with 1-2” (2-5 cm) per week, up until the last week or two before harvest. Holding back on water during this time leads to sweeter melons.
Succession crops of melons
In our climate we can sow melons three times, a month apart. The first row is from transplants, set outside May 3-6. We direct sow the second bed on May 25, then June 25 and once, on July 15 for a “Last Chance” crop.
Pests and diseases of melons
Like most cucurbits, melons are vulnerable to striped cucumber beetles. These pests chew on plants and spread diseases, such as bacterial wilt and mosaic virus. Protect against cucumber beetles with rowcover or insect netting applied at transplanting, or hunt them every morning on leaves and inside flowers, when beetles are more slow-moving. Watch for aphids in the garden, as they can also spread viruses. You can usually hose off leaves or apply an insecticidal soap to kill aphids before they inflict too much damage. In warm, humid climates like ours, melons are subject to powdery mildew, which can wipe out a melon crop if not caught in time. Look for melon varieties that are disease resistant.
Sudden wilt is caused by cold weather in late summer when the plants are loaded with ripening melons.
I recommend harvesting daily, in the mornings, once the dew has dried, to avoid spreading fungal diseases.
With muskmelons, when the background-color of the skin beneath the “netting” changes from gray-green to buff or a yellowish color, the melon is almost ripe. A honeydew melon will turn a light yellow-white color when it’s ripe.
For some varieties (but not all), if gentle pressure is applied to the base of the stem, and the stem separates from the vine, the melon is ready. This is called the “full slip” stage. (The half-slip stage requires a bigger nudge.) Crenshaw and Canary melons require a good tug (“forced slip”). Honeydew, Charentais, and Piel de Sapo must be cut from the vine – don’t wait for them to slip!
Storage time for melon depends on the type. Relative humidity should be 85-95% for best results. Muskmelons will last a couple weeks at 40°F (4°C); honeydew can be stored up to three weeks at 50°F (10°C). Store other melons at 45-50°F (7-10°C) for 7-14 days.
Other small fruits available in July
Blackberries, blueberries, crabapples, elderberries, gooseberries, goumi berries, mulberries, peaches, black and red raspberries.
Water all fruit crops. Pack away blueberry netting after fruiting. Mow aisles, weed and water all fruit.
In late June/early July (after fruiting): Renovate one-year-old strawberry beds to carry over for another year, by mowing or shearing/clipping the plants, weeding and mulching, but don’t compost them at this stage. Dismantle two-year-old strawberry beds after gathering any propagation material.
If preparing to plant new plug-strawberries, till an area in late June or very early July and sow buckwheat by July 4. After three weeks, till in the buckwheat and prepare the beds.
If preparing to plant bare-root strawberries, (perhaps rooted runners in the paths of older beds), till the area by the beginning of July and prepare new beds with compost, driptape, and landscape fabric.
In early July, or at least by mid-July, plant new bare-root strawberry transplants.
July 6-14: To propagate from your own plants, pot up pencil-thick crowns, with 2 or 3 leaves, 4” (10cm) petioles. Use Round-50 plug trays. Or use runner tips. Set up a shadecloth propagation tent in a cold frame, or other protected area Set up a misting system and timer. Also handwater once or twice a day, to keep the soil damp.
See my recent post for info about fall broccoli and cabbage. Here I provide some more information and discuss other brassicas you could grow in the fall.
Temperature and Timing for Fall Brassicas
Germination: Brassica seeds will germinate at soil temperatures from 41°F (5°C) to 95°F (35°C). 41°F (5°C) can take 45 days for some brassicas, but in summer and fall, this isn’t the end of the thermometer we worry about! In summer and fall, soil temperatures are enough to germinate brassicas in 3-10 days. Optimum soil temperatures for germination are
77°F (25°C) for most Asian greens, broccoli, Brussels sprouts, cauliflower, collards, kohlrabi, pak choy;
86°F (30°C) for cabbage, including Napa cabbage, kale, turnips and rutabagas;
68°F (20°C) for mustard greens, and perhaps arugula (which might do better even cooler)
Cold-Hardiness: Consult this list of winter kill (air) temperatures for brassicas, for the crops you are growing.
32°F (0°C): some cauliflower curds, some pak choy
27°F (-3°C): many cabbage varieties
22°F (-6°C): some varieties of arugula
20°F (-7°C): broccoli heads (maybe OK to 15°F (-9.5°C)), some Brussels sprouts, some cabbages (the insides may still be good even if the outer leaves are damaged), some cauliflower varieties, some collards (Georgia Cabbage Collards, variegated collards), some mustards/Asian greens (Tendergreen), radishes (Cherry Belle), most turnips (Noir d’Hiver is the most cold-tolerant variety).
15°F (-9.5°C): some broccoli and cauliflower leaves, some cabbage (Kaitlin, Tribute), Red Russian and White Russian kales, kohlrabi, rutabagas (American Purple Top Yellow, Laurentian), most covered turnips, winter cress.
12°F (-11°C): some broccoli perhaps, some Brussels sprouts, some cabbage (January King, Savoy types), most collards, Koji greens, covered rutabagas
10°F (-12°C): Purple Sprouting broccoli for spring harvest, a few cabbages (Deadon), some collards (Morris Heading can survive at least one night), Belle Isle upland cress, probably Komatsuna, Chinese Thick-Stem Mustard may survive down to 6°F (-14°C), covered winter radish (Daikon, China Rose, Shunkyo Semi-Long survive), Senposai leaves (the core of the plant may survive 8°F/-13°C), Tatsoi, Yukina Savoy.
5°F (-15°C): some kale (Winterbor, Westland Winter), many of the Even’ Star Ice Bred greens varieties and the Ice-Bred White Egg turnip are hardy down to 6°F (-14°C)
0°F (-18°C): some collards (Blue Max, Winner, McCormack’s Green Glaze), Even’ Star Ice-Bred Smooth Leaf kale
-5°F (-19°C): Leaves of overwintering varieties of cauliflower, Vates kale survives although some leaves may be too damaged to use. Lacinato Rainbow Mix kale may survive this temperature.
Your Climate: Consult WeatherSpark. com to see when it begins to get too cold in your area. At our farm, the average daily low temperature on November 30 is 36°F (2°C). Decide your ideal harvest date for each crop. Although kohlrabi can take 15°F (-9.5°C), I’d want to get it all harvested by November 30.
Days to Maturity: Next factor in the number of days a crop takes to reach maturity. Work back from your desired harvest date, subtracting the number of days from sowing to maturity (or from sowing to transplant, plus from transplant to maturity). Work back another two weeks for the slowing rate of growth in fall. And perhaps work back another two weeks in case in gets colder earlier than usual. This provides your sowing date.
Mid-Winter Harvests: For crops that survive your winter, are you sowing to harvest in the fall, during the winter, or only in early spring? Brassicas for early spring harvest only can be sown in September or October in our climate. For those to be harvested during the winter, you need to have big enough plants going into the winter, to provide sustainable harvests (once a week in November and February and more in spring, plus maybe once a month in December and January)
Various Fall Brassica Crops
In the summer we try to have a No Visible Brassicas Month to break the lifecycle of the harlequin bugs. Once our spring kale is finished, the spring cabbage gathered in, and the spring broccoli mowed down, the only brassicas are seedlings hidden under insect netting. Our hope is to starve out the harlequin bugs or at least deter them from making too many more.
We sow other fall outdoor brassicas a bit later than cabbage and broccoli. These get transplanted from our netting-covered nursery seedbeds, to our raised bed area which is more accessible for winter harvesting and more suited to small quantities.
Outdoors we grow Senposai, Napa Chinese cabbage and Yukina Savoy. We have also sometimes grown tatsoi and komatsuna. Note that senposai grows quite large – give it similar spacing to collards.
We sow Asian greens for outdoors in the last week of June and first week of July, aiming to eat them before we start harvesting the ones in the hoophouse, which feed us all winter. We use Asian greens outdoors as quick-growing greens to fill the gap before our main fall greens (spinach, kale, collards, cabbage, broccoli) are ready to harvest. We don’t grow a lot outdoors.
If you don’t have a hoophouse, you can sow for outdoors later into the fall than we do, to get a longer harvest season than you otherwise would. And you certainly can direct seed them.
We sow collards in the first two weeks of July and transplant the bare-root transplants from the nursery bed when they are 3-4 weeks old. We plant at 18” (46 cm) in the row, with rows 12” (30 cm) apart. (if you grow a large kale, you might want similar spacing. Our Vates kale is small)
are rather a challenge in our climate, and not worthwhile. We have worked on finding the best variety (Oliver) and timing for our situation. Harvest timing is critical, as Brussels sprouts will not overwinter here.
are a tricky crop for us too. Be sure to check the “days to harvest” for each variety (they vary widely) and sow at a realistic date to get a crop before too many frosts endanger the curds. The number of days quoted for fall varieties of cauliflower already allows for the expected rate of growth at that time of year, so the 14 days for slower growth isn’t a factor. However, cauliflower is more tender, so allow for the possibility of a fall frost earlier than average.
We sow Vienna kohlrabi mid-July and transplant early August at 8” (20 cm) apart in the row, with 9-10” (23-25 cm) between rows. Later sowings (up till early September) would also work for the fast maturing varieties. Superschmelz Kohlrabi (60 days from transplanting) can also be summer sown for fall harvest. It produces 8-10” (20-25 cm) bulbs, which remain tender and an attractive globe shape.
We direct-sow two neighboring beds of kale on each of 8/4, 8/10, 8/16 and then carefully thin them, leaving one plant every 12” (30 cm). These plants grow quicker than transplants, as they have no transplant shock. Meanwhile, if we have gaps, we use the carefully dug thinnings from those beds to fill them. We want a lot of kale, and there isn’t time to transplant it all. Dividing up the sowings lets us focus on watering just one pair of beds at a time. Vates kale is the hardiest variety we have found, although I’d love to find a taller Scotch curled variety that could survive our winters (Winterbor does not survive as well as Vates).
Radishes, rutabagas and turnips are also brassicas, but I won’t say more here. look in the further resources.
Brassicas started in hot conditions do not usually bolt if they have enough water.
Protect seedlings and the new transplants with insect netting if you have brassica leaf pests (most of do!) You can remove the netting when the transplants are well established, or leave it on.
Use shadecloth to keep greens cool in hot weather, or plant them in the shade of other plants.
To keep crops in good condition later into the winter, use rowcover. I recommend thick Typar 1.25oz rowcover, which provides 6F degrees of cold protection. I wouldn’t spend the money on anything thinner, it’s too frustrating! We do not normally use rowcover in the winter for kale and collards, as they will survive without. In harsh winters we lose the collards.
Cultivation is a simple matter of hoeing, weeding, watering as needed, and watching for pests.
Book Review: Manage Weeds On Your Farm: A Guide to Ecological Strategies, by Charles Mohler, John Teasdale and Antonio DiTommaso. SARE Handbook 16, 2021, 416 pages, color photos, drawings, charts, $24.00
This immense book is a game-changer! A resource enabling us to understand weeds better and deal with them smartly, exploiting their weaknesses, making best use of natural and created resources.
About 300 pages comprise a directory of major agricultural weeds of the United States and Canada: about 20 grasses and sedges; about 45 types of broadleaf weeds. Many of the weeds in North America came from Europe, so the book’s usefulness is not restricted to this continent. The focus is on weeds of arable farmland. Gardens fit in this category, although the physical tools will be smaller! This part of the book is not merely to help you identify weeds, but to develop a management plan for each one.
The first part of the book is 120 pages of agricultural gold – an exploration of concepts of ecological weed management. Understanding the biology of weeds is vital to successful ecological management. (Note that I’m avoiding the use of the word control, as the authors do.) The book is “intended to provide the information you need to grow crops without synthetic herbicides, great expense or back-breaking work.” Good information is an efficient tool. Understanding more about how the biological world works will enrich your life!
This is not a book many of us will read cover to cover. It’s a toolbox. Read the first section, then seek out the profiles of your most problematic weeds and make a plan for each one. In each profile there is an identification section with good photos, a management section, a concise summary, referring back to cultural and mechanical strategies, and an ecology section with specific information leading to the recommendations in the management section.
Chapter 2, How to Think About Weeds, starts with the reminder that weeds die from various causes (any of which we can use to advantage). Seeds may fail to germinate, or get eaten. Seedlings die from drying out, disease, competition from other plants, or lack of light, or being eaten, mowed or turned under.
“The goal of ecological weed management is to arrive at a balance between birth and death that keeps the density of weed populations low most of the time and reduces them quickly when density starts to increase.”
You need to increase the death rate and reduce the germination rate of the weed seed bank, or else the population continues to increase. This demonstrates the value of understanding which tools to use in which situation. Keeping on hammering with a wrench will not work well!
Seed size is one of the characteristics of weeds that affect their successful management. Smaller seeds are easier to kill, because the seed does not provide much food for the seedling. Large-seeded crops and transplants can out-compete small-seeded weeds, if the timing of cultivation is right. There is a good explanation for why tillage prompts seed germination, which can give weeds the upper hand. Environmental cues such as soil temperature, the difference between night and day temperatures, oxygen levels, even a brief flash of light, can indicate if the seed is near the surface and whether there are competing plants up there. The cues can be very specific. Velvetleaf and tall morning-glory germinate in response to a sudden absence of certain volatile compounds which are vented from the soil during tillage. Understanding this Secret Life of Plants can help us figure strategies for specific weeds.
Different weeds germinate in different seasons, and crop rotation between spring, summer and fall crops will disrupt weed lifecycles and prevent any one taking over. Another consideration is that the same percentage of the seeds still in the soil will die each year. This means that if no fresh weed seed is added, the seed bank declines rapidly in the first few years, leaving some seed persisting for years.
The main cause of seed death is probably that seeds germinate in unfavorable conditions and then die. Secondly, seeds are eaten. Lastly, some seeds rot and decompose. Small seeds deep in the soil are unlikely to germinate. It takes a big seed to provide the resources to grow a shoot that can reach a long way to the surface. Galinsoga seeds rarely emerge from deeper than ¼” (6mm). Few seeds can germinate from deeper than 2” (5cm).
Nowadays we are learning about two photosynthetic pathways, C3 and C4. C3 plants thrive in cool, moist conditions, not needing full daylight to maximize their photosynthesis. Most cool-season grasses and broadleaf weeds use the C3 pathway. They can increase photosynthesis (grow more) as CO2 concentration in the atmosphere increases. C3 crops like potatoes, pumpkins and soybeans will probably do better against C4 weeds as CO2 concentration increases in the climate disaster. C4 plants perform best at high temperatures, with more sunlight enabling more photosynthesis. Bermuda grass, foxtails, pigweeds, and common purslane use the C4 pathway. But C4 crops such as corn will have a harder time with C3 weeds. If your climate becomes warmer and drier, C4 weeds and crops will be favored over C3 weeds and crops. This effect may be stronger than the effect of increased CO2.
Other factors influencing growth include frost tolerance, drought tolerance, and the presence or absence of mycorrhizal fungi. The majority of flowering plants do form mycorrhizal associations, but many weeds and some crops do not. Brassicas, chenopods (spinach, beets, lambsquarters, amaranths), smartweeds and sedges do not. Mycorrhizae assist the growth of host plants by providing nutrients and a good growing environment. When conditions favor mycorrhizae, those crops are more competitive against non-mycorrhizal weeds.
The diameter of the roots also has a role. Large-seeded crops tend to have large diameter roots, while small plants tend to have small diameter roots, which can grow longer faster. Pigweed (small seeds) after 28 days of growth has a root-length:weight ratio eight times higher than sunflower (large seeds). Pigweed roots are better at gathering nutrients, because they explore more of the soil, and can absorb more nutrients (because the ratio of surface-area:volume is greater).
Some weeds flower near the end of their lifecycle, after growing quite large, in a “big bang” (pigweed and lambsquarters). Removing these weeds early in life prevents the competition from these large plants that reduce the crop yield. If you miss that opportunity, killing the weed later in life (before it seeds) will help future crops. Other weeds are “dribblers” – they start to set seed while still small. They can hide among the crop plants, making seed whenever conditions are favorable. Failing to remove these weeds early in life will potentially reduce yields for many years. This is how galinsoga can be such a nuisance in vegetable farms, surviving where the soil is frequently cultivated, and sometimes neglected long enough for seeds to mature. It’s always worth hand-pulling a large galinsoga as you walk by, as the largest plants produce the most seeds.
All plant species have natural enemies (diseases and pests that have co-evolved to live in balance), plus the occasional alien plant enemy that could devastate the population. Consequently, there are few natural enemies of weeds other than imported ones. Bio-herbicides are rare. But there are less obvious natural enemies of weeds. The authors measured the mortality of lambsquarters and redroot pigweed in the absence of human intervention. 80% or more of the lambsquarters emerging after tillage died before maturity. Fungi and insects were the likely predators. Results with pigweed were similar.
There is a chart of edible weeds for those inclined to engage in direct weed eradication, and the chart includes cautions about toxic parts of each plant.
The chapter summary lists ten important lessons. Dealing with roots and rhizomes of perennial weeds; rotating between spring, summer and fall-planted crops; influencing when weed seeds germinate and when they die; using transplants; using slow release nutrients to feed your crops rather than the weeds; avoiding over-fertilization; preventing weeds from seeding; reducing arrival of new weeds on your farm.
Chapter 3 is about cultural weed management. Ecological weed management involves “many little hammers”, using multiple strategies together in a complementary way. Crop rotation is one that involves advance planning. Spring weeds can be destroyed while preparing the soil for summer planting, reducing future pressures in spring crops. Good stands of overwintering cover crops, especially mixtures, can inhibit winter and spring weed germination. The diversity of field operations associated with particular crops is as important as the diversity of the crops themselves.
Growing healthy competitive crops is a fundamental part of weed management, and involves many aspects, starting with using high vigor, fast-germinating seeds. Planting the crop at an appropriately dense spacing will reduce weed opportunities. Any crop that produces multiple harvests (kale, tomatoes, squash) can be planted closer than most recommendations without loss of yield, whereas those with a single harvest (cabbage, lettuce, corn, root crops) will get smaller if planted too close. Planting 50% closer is usually worth trying, for a higher total yield, when smaller individual units are acceptable. Thus may involve more time harvesting, and bigger seed purchases. The reduction of weeds may benefit many subsequent crops.
Other factors not yet mentioned include row spacing, row orientation (plants get more light in rows that run N-S), choice of fast-growing or large-leaved varieties (Danvers are better at shading than Nantes type carrots), planting date (avoid the period when the dominant weed species is likely to grow vigorously), intercropping (practice with caution, avoid having two crops in competition), nutrient and water supply.
No-till cover crops, where the residue remains on the soil surface, will inhibit many weeds, and provide many other ecological benefits. Organic no-till isn’t the answer for every situation. It keeps soil cool and somewhat compacted, and doesn’t release its nutrients quickly, so it isn’t good for early spring crops, or early warmth-loving crops. To sow the necessary good stand of cover crops, tilling is required. This means no-till can have a valuable place in your rotation, but continuous organic no-till is not likely to work.
Tarping is a method of covering the soil with large opaque tarps for several weeks, to germinate and then kill emerging weeds by depriving them of light. This provides a seedbed ready to plant. Tarping can also be used to kill mowed cover crops or crop residues. Tarping can be useful in the transition from tilled to no-till farming, while weeds are still a big challenge.
Solarization is another soil-covering practice, this time with clear plastic and the goal of heating the soil to kill weed seeds, pests and disease organisms in the top layer of soil. This method works in hot weather in areas with a good amount of sunlight. It works best when the plastic is laid tightly over well-prepared beds, providing good soil contact. The edges are buried to hold in the hot air. It takes several weeks to kill weed seeds, even when conditions are right.
A flock of chickens can do a good job of weed management, if penned in the vegetable garden early enough to allow 90 days after their removal before the crop is harvested (above ground crops) and 120 days for in-ground crops. These are commonsense food safety precautions required for Organic certification.
There are two main approaches to weed management. The first is to remove enough weeds so that crop yields are not compromised in an economically significant way. The second is to minimize weed seed production, aiming for very low weed populations, meaning little weed management work in the future. This preventive weed management requires more precise attention in the early years, including removing weeds that are not, in themselves, causing measurably lower yields. Either approach can be successful, but the preventive strategy is a good one for people who are growing older (!) and want less work in the future, while maintaining an income and satisfying work.
Chapter Four covers mechanical and other physical weed management methods. “The effect of tillage or cultivation on a weed population depends on the interaction between the nature of the soil disturbance and the ecological characteristics of the weed.” In other words, to control a particular weed, we need to know the features of that weed and choose methods of cultivation and tillage that will exploit the weaknesses of that weed, and take account of the weather, the soil conditions and the crop stage. Timing determines success, and the greatest success comes from using a planned sequence incorporating several operations.
There is a very clear explanation of vegetative reproduction of perennial weeds and how to thwart that process. Tilling chops up roots, which grow into new plants. Partial damage to perennial roots stimulates sprouting of dormant buds. The best chance of success comes from exhausting the root or rhizome pieces. With most perennial weeds, carbohydrates flow from the storage organ into the leaves until they produce enough food to return some to the root. The ideal stage to kill such plants is when the pieces of the storage organs drop to their minimum weight after growing new leaves. Generally this is after three or four leaves have grown.
Tilled fallow is a time without crops, when the plot is tilled often enough to stop weeds proliferating. Most annuals take 5 weeks to set seed, and so once every three weeks is a good tilling frequency, for management of both perennial and annual weeds. This will inevitably damage the soil structure. Growing a fast cover crop (buckwheat or a mustard) between tillages will reduce the damage.
A discussion of ten Principles of Mechanical Weeding follows. A useful chart of two dozen weeding implements and tools provides information on when and how they are best used, which crops they are most suited to and what their limitations are. The chart is followed by pages of clear drawings of various cultivators, with explanations of when they are most useful.
Often one goal is the creation of a surface layer of small aggregates allowing good air circulation and decreasing germination of new weeds. This is widely called a “dust mulch”. Weeding early, shallowly and often, is widely shared advice. Shallow soil disturbance can eliminate a large percentage of annual weeds, without bringing new seed to the surface. Small weeds do not re-root easily, as they have only small reserves of energy. Weeds over 2” (5cm) tall are more likely to re-root.
After the profiles of five farms with great weed management strategies, explaining their overall approach to weeds, comes the directory of weeds, including information on resources, naming, ecological information, recommendations for management and the limitations of those recommendations (for example, whether or not they have been field-tested).
There are summary tables of summer annual weeds, winter annual weeds, and perennial weeds, each subdivided into broadleaf weeds and grasses, with information on characteristics. To help with visualizing seed sizes from the weights given, they helpfully tell us that a lettuce seed is likely to weigh 1mg. The tables are followed by 3-4 page profiles for each weed, including several clear photos of the weed at different stages of growth, management suggestions, ecology and a handful of references for further reading.
There are tips on developing management plans for weed species that are not in the book. Some weeds are a big problem in a small geographical area, and of not much consequence elsewhere. Record your own observations, using the questions provided to focus your attention and identify the weed. Each taxonomic level (family, genus, species) can provide actionable information. There are some great resources for weed identification, leading me to find one from Virginia Tech https://weedid.cals.vt.edu/.
There is hope for dealing with even the worst weeds! “Competitive cover crops are effective for suppressing bermudagrass.” Example: A dense fall sowing of winter rye, barley or oats, harvested for forage in spring, with the stubble plowed under to allow sowing of a very competitive summer cover crop like cowpeas. The dense shade following the late spring soil disturbance will suppress the grass.
The directory is the main part of the book, and the part where you will want to search out your worst problems and form a plan. Keep this book in a place you can always find it when needed, for the rest of your farming life!
We are almost at a big turning point of the growing season, the Summer Solstice, the longest day. We know that day-length influences plant growth, and that after the Solstice, some crops will gradually take longer and longer to reach maturity (others will bolt). Crops more influenced by temperature (like sweet corn) will continue to mature faster while the summer temperatures rise.
Here in central Virginia, most brassicas are planted in spring and again in fall. Unless your broccoli keeps going all summer, consider sowing a new crop for fall. Although it can be hard to think about sowing seeds in mid-summer, it’s very worthwhile to grow fall brassicas because as they mature in the cooler fall days they develop delicious flavor, while weeds and pests slow down. These crops need little care once established. The most challenging part is getting the seedlings growing well while the weather is hot. However, unlike some cool weather vegetables such as spinach and lettuce, brassica seeds actually germinate very well at high temperatures. The ideal is 77-85°F (25-29°C), but up to 95°F (35°C) works. Given enough water, summer seedlings will emerge in only 3 days. Once they have emerged, the challenge begins. As well as temperature and moisture in the right ranges, the seedlings need light (very plentiful in mid-summer!), nutrients, good airflow, and protection from bugs. We deal organically with flea beetles, Harlequin bugs, and sometimes cabbage worms. Our main defenses are farmscaping, and netting (and previously, rowcover).
My book Sustainable Market Farming, has a chapter devoted to Broccoli, Cabbage, Kale and Collards in Fall.
Timing sowing of fall broccoli and cabbage
The number of days to harvest given in seed catalogs is usually that needed in spring – plants grow faster in warmer temperatures. To determine when to sow for fall plantings, start with your average first frost date (as an indicator of cooling temperatures), then subtract the number of days from seeding to transplant (21-28), the number of days from transplanting to harvest for that variety (given in the catalog description), the length of harvest period (we harvest broccoli for 35 days minimum), and another 14 days for the slowing rate of plant growth in fall compared to spring. For us, the average first frost is 10/14-10/20, and we sow 53-day broccoli 21+53+35+14 days before 10/14, which is 6/13-6/19. The last date for sowing broccoli and cabbage is about 3 months before the first fall frost date. In our case that means July 14–20.
Planning and crop rotations for fall brassicas
Our rotation plan shows us a long way ahead how many row feet of fall broccoli and cabbage we can fit in. By the time we order our seeds in the New Year, we know roughly what we expect to grow. In February we draw up a spreadsheet of how much of what to sow when.
Because fall brassicas are transplanted in summer, it’s possible to grow another vegetable crop, or some good cover crops, earlier in the year. An over-wintered cover crop mix of winter rye and crimson clover or hairy vetch could be turned under at flowering, and be followed by a short-term warm weather cover such as buckwheat, soy or cowpeas. Brassicas are heavy nitrogen consumers. To minimize pests and diseases, don’t use brassica cover crops.
Systems for growing fall broccoli and cabbage transplants
The same systems you use for growing transplants in spring can also work well for fall. It can help to have your plants outside on benches, above the 3’ (1m) height of flea beetles. A shade-house might be ideal too. Direct sowing, in “stations” (groups of several seeds sown at the final crop spacing), works for small areas.
We use an outdoor nursery seedbed and bare root transplants, which suits us best. The nursery bed is near our daily work area, so we’ll pass by and water it. Having the seedlings directly in the soil “drought-proofs” them to some extent. They can form deep roots, and do not dry out so fast.
For the seedbeds we use ProtekNet on wire hoops. Choose the mesh size carefully. One with small holes is needed to keep flea beetles away – 25 gm or 47 gm. Overly thick rowcover can make the seedlings more likely to die of fungal diseases in hot weather – good airflow is vital.
Sowing fall broccoli and cabbage
Our rough formula for all transplanted fall brassicas is to sow around a foot (30 cm) of seed row for every 12-15’ (3.6-4.6 m) of transplanted crop row. We aim for 3 seeds per inch (about 1 cm apart). This means sowing 36 seeds for 10 plants transplanted on 18” (46 cm) spacing. And we do that twice (72 seeds for 10 plants!), in two sowings a week apart, to ensure we have enough plants of the right size.
Our seedbeds have an 8-week program – see the spreadsheet above for examples of our timing, quantities and varieties. I like to have a regular afternoon every week to grow the transplants. If you’re growing for fewer than 100 people, you won’t need a whole afternoon! Each week after the first week, we also weed the previously sown plants, and thin to 1” (2.5 cm) apart. Then we check the germination, record it, and resow if needed to make up the numbers.
Transplanting fall broccoli and cabbage
We transplant most brassicas at 4 true leaves (3-4 weeks after sowing at this time of year). It is best to transplant crops at a younger age in hot weather 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 transplant 6 days a week for an hour and a half or two hours in late afternoon or early evening, for 2-3 weeks. We water the soil in the plot an hour before starting to transplant. It is very important at this time of year to get adequate water to the plants undergoing the stress of being transplanted. Likewise, good transplanting technique is vital. Water a lot more than you do in spring. If you have drip irrigation, you can easily give a little water in the middle of each day too, which will help cool the roots.
We transplant broccoli and cabbage in 34” (86 cm) or 36” (91 cm) rows, which is wider than necessary. Beds or paired rows can fit more plants in the same space, while still allowing room to walk. We hammer in stakes along the row, and attach ropes between them. These both mark the rows for transplanting, and support the netting that we use after transplanting to keep the bugs off. An 84” (2.1 m) width netting can form a square tunnel over two crop rows, giving good airflow. Wire hoops are an alternative. Watering the soil before planting, as well as afterwards, helps survival during the hot summer days.
Aftercare of fall brassicas
About a month after transplanting the broccoli and cabbage (late August-early September), we remove the netting, stakes, ropes and the sticks we use to hold down the netting edges, then hoe and till between the rows. Next we broadcast a mix of mammoth red clover, Ladino white clover and crimson clover. We use overhead sprinkler irrigation to get the clover germinated, and it also helps cool the brassicas. The ideal is to keep the soil surface damp for the few days it takes the clover to germinate. Usually watering every two days is enough. We may replace the netting if pest pressure seems bad.
If all goes well, we keep the clover growing for the whole of the next year, mowing several times to control annual weeds. You could, instead, till in the clover in late spring or early summer to plant a food crop then.
Harvesting fall broccoli and cabbage
We harvest all our brassicas three times each week, and take the produce directly to our cooler.
Our main broccoli harvest period is 9/10-10/15, with smaller amounts being picked either side of those dates We like our broccoli heads to get as large as possible (without opening up) before we harvest. We test by pressing down on the head with our fingertips and spreading our fingers. We harvest as soon as the beads start to “spring” apart. This may be a little late for other growers. We also look at the individual beads and aim to harvest before the beads even think about opening. We cut the stem diagonally to reduce the chance of dew and rain puddling, which can cause rotting of the stem. Later we harvest the side shoots, until they are too small to bother with.
Cabbage heads up from 9/25 and holds in the field till late November. Cabbage is mature when the outer leaf on the head (not the outer plant leaves which are left in the field) is curling back on itself. For storage cabbage, we set the cut heads upside down on the stump, in the “basket” of outer leaves, and come back an hour later to gather them into net bags. This allows the cut stem to dry out and seal over, improving storability.
If you are already looking ahead to the fall, see my post Fall and Winter Vegetable Growing, Harvest and Storage, for lots of links to more info on season extension into cold weather; fall and winter vegetable harvests; and fall and winter vegetable storage. I will write more about other fall brassicas in the near future.
This is another post in my new monthly series, about small fruits that can be grown sustainably in a mid-Atlantic climate. I’ll talk about planting, pruning, harvesting and care of the plants, according to the season. I’ll give links to useful publications. I’ll have a focus fruit, and then more about others that need attention during the month. We do grow apples and pears, and some other tree fruit, but I’m not writing about those as I don’t have much recent experience.
Blueberries are the focus fruit for June
June is the month in our climate, to harvest blueberries. Blueberries are a great crop to grow, as they are not troubled by many pests or diseases (apart from birds). While you are harvesting take notes (or photos) of the various varieties you have, and when and how well they are producing, so that you will know which ones to propagate from in the winter, if you want more.
See ATTRA Blueberries: Organic Production available free online, for a wealth of information from choosing varieties, planting, details on pests and diseases you might encounter. Updated 2022. Also search the ATTRA site for other info on blueberries, such as soil management (blueberries need acid soil), living clover mulches, and honeybees and alternative pollinators.
I recommend harvesting two days a week, in the mornings, once the dew has dried, to avoid spreading fungal diseases. Blueberries don’t deteriorate or over-ripen as quickly as softer fruit, so if you can only find time once a week, that will be OK. Or if you are selling blueberries, once a week may work better for your sales. Blueberries don’t crush as easily as strawberries or raspberries, so if you have lots you can put them in buckets or crates. We usually harvest into homemade berry buckets with long rope handles, that we can hang around our necks, freeing up both hands for picking berries. Our berry buckets are made by cutting plastic gallon jugs and adding rope through holes we punch near the top. Full berry buckets get emptied into a bigger bucket.
Only pick the berries that are purple-black all over. Check the back of each each ripe-looking blueberry to make sure it’s ripe all over. The area around the stem is the last to change color. Really ripe blueberries will “tickle” from the bush into your hand
Do not wash fruit before refrigerating, as this leads to rot.
Types of blueberries
We grow Northern Highbush blueberries here in winter-hardiness zone 7a (suitable for zones 3-7) and we like to have a crop we can harvest standing up! There are also lowbush blueberries, which are popular in cooler climates, such as Maine. Rabbiteye varieties are better to the South, in the region roughly south of Interstate 40 (mostly zones 6-9). Rabbiteyes are taller plants, with smaller berries than highbush types. A new hybrid type, Southern highbush, is adapted to the southern rabbiteye zone and the coastal South (zones 6-10). Look into these if you are in the right area: they have a lower chilling-hours requirement, and flower and fruit earlier than highbush or rabbiteye varieties. As the climate changes, fruit growers are challenged by traditional crops no longer getting enough winter chilling hours to fruit. (Chilling is the number of accumulated hours at temperatures below 45°F/7°C in the dormant season.) Balance this with your changing frost dates, as earlier flowering will not be an advantage if your last frost is going to cancel the fruit. Remember that all blueberries are self-fertile but will produce better crops if you plant several compatible cross-pollinating varieties.
At our farm, Duke has been a very reliable early fruiting highbush variety, whereas Spartan has not worked out. We like to have several varieties with different ripening dates, to extend the harvest. Blue Crop, Blue Jay, Elliott and Chandler also do well here. If I was starting over, I’d also try some Southern Highbush varieties.
We have bought good plants from Finch Blueberry Nursery in Bailey, North Carolina, as well as from a more local source in SW Virginia (now retired). If you only want a few plants, buy potted blueberry plants locally. Otherwise, order bareroot plants shipped to you. In Virginia Edible Landscaping offers a wide choice.
When to plant blueberries
If you are planning to plant blueberries, here are some considerations. Generally you will want o buy young bushes and plant them in the dormant season. In warm areas, plant in late fall so the plants get roots established before your early spring thrusts them into opening buds. In cooler zones, plant in early spring, so that winter does not kill them.
As with all perennials, clear the area of perennial weeds the previous year, and reduce annual weeds, for instance by growing a good cover crop, which will smother emerging annual weeds and also feed the soil. Get a soil test, and follow the recommendations to amend the pH to 4.8-5.5 using sulfur in spring or fall before planting. I like the pelleted sulfur, that looks like lentils, because it is easy to spread, and no dust gets in your lungs. Depending on your soil type, you might need 430-1750 pounds of S per acre, or 1-4 pounds per 100 sq ft. Work in some good compost before planting.
Plan space between the rows that will let you walk, mow or whatever you need to do even once the bushes have reached full size. 8-12ft is recommended. Ours are a bit closer than that. In the row you can either plan for a hedge effect, or leave yourself access space. You can plant blueberries on raised beds or wide ridges. You can move bushes later in life, if you find they are competing too much.
Plan how you will cover the soil. I recommend landscape fabric topped by bark mulch or woodchips. This combination works well to keep perennial weeds at bay (wiregrass!). If you are avoiding plastic, you can use double layers of overlapping cardboard topped by 3” of organic mulch: chips, sawdust, straw or spoiled hay. Blueberries don’t do well with plastic mulch that is impervious to water, as it encourages the roots to grow just under the plastic, where they can easily get overheated and die. Some people like to grow a living mulch, perhaps mowing it to mulch closer around the plants once it dries. A hybrid model has mulch in the rows and a cover crop between the rows.
Blueberries have shallow roots, so you will likely need some irrigation method. I like drip irrigation, but overhead sprinklers work too.
You will, of course, have some annual care to provide. Each spring, expect to provide some source of nitrogen and potassium, as needed. I’ll cover that another time. Each winter, prune for strong branches and good levels of production, and remove any perennial weeds.
Pests to watch out for include big ones like deer, groundhogs, birds and uninvited humans. We have a triple fence, with wire netting in the ground against burrowing animals, 7’ tall Tenax deer fencing, and seasonally, Avigard flexible bird netting over the top. For our newer blueberry planting we make a temporary hooped structureand cover just with the bird netting, held down to the ground with 6” soil staples. This planting is nearer our buildings than the older one, and is not visited by deer or groundhogs.
Smaller pests include blueberry maggots, blueberry stem borers, cranberry fruitworms, cherry fruitworms, Japanese beetles, leafrollers, leafhoppers, and aphids. Our perhaps, like us, you will not be troubled by any of these.
Diseases include mummy berry, Botrytis grey mold, Anthracnose, stem blight, stem canker, rust, phytopthora root rot, Phomopsis twig blight, blueberry stunt and several viruses. A Cornell University blueberry diagnostic tool offers a step-by-step exercise to help figure out what diseases may be affecting your crop.
Grapes: Mow, weed, water in drought. If you have young vines, remove side branches from the trunks, and fruitlets. Your goal is to first grow strong plants, then produce grapes after that.
Strawberries: Prepare for new strawberries in early June: Disk or till the area for new strawberries if using bare-root plants, and prepare the beds with compost, driptape, and landscape fabric.
June 16-July 16: If using bare-root transplants, plant new strawberry beds.
Late June/early July (after fruiting): Dismantle two-year-old beds. Renovate carry-over strawberries by mowing or shearing/clipping weed and mulch, but don’t compost them. . Plant new strawberries if using bare-root transplants, perhaps rooted runners in the paths of older beds.
All fruit: Water all fruit crops. Weed, mow aisles as needed. Weed and mulch rhubarb, lop flowers. Record condition and fruiting dates of new grapes, blueberries. Note best varieties.
I started to make in-person bookings again a year ago, then Omicron arrived and lots of conferences switched to being virtual. The only in-person event I attended this spring was the PASA conference, which I enjoyed a lot. I am still doing some virtual events, and planning some live ones too. Everything is subject to change!
As of right now I have two in-person events booked, and one new podcast interview. June and July are the months for speakers to apply to make winter and spring conference presentations, so I’ll be doing that! See my Events Tab for ideas I have of which events to apply to.
CAFF was developed to strengthen and expand our food and farming system, enhance local communities, and provide opportunities for farmers, food entrepreneurs and food system leaders.
Combining traditional and experiential learning opportunities, their Farm School and Apprenticeship programs teach the production and business skills to develop resilient and sustainable businesses.
CAFF is dedicated to increasing the number of thriving farms and farmers in Arkansas. To accomplish this, the center provides farm education, training, networking, and resources. Creating a supportive farm community network will bring more people into farming and help retain current farmers by increasing their success.
Join CAFF at the farm to learn about extending your growing season with high tunnels. Space for this class is limited.
The CAFF Jan. 11 to March 1 two-hour courses remain available for viewing through Oct. 31. To pay the $10 access fee, please visit the registration page and email Heather Friedrich, program manager, at email@example.com to confirm receipt.
Make the most of your space and time growing vegetables at home using planting schedules and techniques timed to the seasons, seed varieties, crop rotation, and use of protective structures such as coldframes and greenhouses. Learn labor saving and innovative planting and soil fertility techniques for growing and harvesting a full range of fresh, delicious, organic vegetables. Fill your salad bowl and dinner plate year round!
Accidental Gods Podcast
Exploring the liminal space between science and spirituality, philosophy and politics, art, creativity – working towards the conscious evolution of humanity.
Accidental Godsis two women, Manda Scott and Faith Tilleray, dreaming of a different future. Faith Tilleray designs the website and the Instagram feed. Manda Scott is a podcaster (also: novelist, smallholder, renegade economist etc. etc. ). Both are living in the UK.
Recently we were given a gift of sweet corn from somewhere warmer than central Virginia. It wasn’t Organic, so I wondered if it was genetically modified. I try to avoid eating GMOs, because I don’t support the practice of inserting bits of other organisms in existing crops. Corn varieties often have Bacillus thuriengensis (Bt) inserted in their DNA with the goal of killing caterpillars that eat corn kernels.
Anything certified USDA Organic is not allowed to have any GMOs in it, so that’s one way to avoid getting GMOs. Growing your own food is a certain way to avoid GMOs, if you don’t buy GMO varieties or suffer cross-pollination from GMO crops.
The Non-GMO Project is the U.S. organization that provides testing and labeling for absence or presence of GMO in products. The “Non-GMO Project Seal” certifies that the product contains 0.9% or less GMO ingredients.
I’m going to skip ahead to talking about which vegetable crops are available in genetically modified varieties, because there are not many, and I’m not interested in worrying people! Then I’ll go into details.
The Big Three GMO Crops in the US
Soy, canola and corn are the three food crops in the US that are most likely to be genetically modified. Starting with corn (maize): 92% of all corn grown in the US is GMO. Of corn grown, only 1% is sweet corn. Of sweet corn grown in 2018, 10% is GMO. When you see a field of corn, it is almost certainly GMO, unless you are looking at an Organic farm.
What is field corn? “Corn (such as dent corn or flint corn) with starchy kernels that are used especially as livestock feed or processed into food products (such as cornmeal, corn oil, and corn syrup) or ethanol,” (Merriam Webster). Of the field corn in the US, 40% goes to make ethanol for vehicle fuels, 40% goes to livestock feed, and 20% goes into processed foods for humans.
In 2000, GM StarLink corn was recalled, when over 300 different food products were found to contain a genetically modified corn that had not been approved for human consumption (only animal feed). It was the first recall of a genetically modified food.
What about wheat? Farmers have shown a distinct preference for not growing GMO wheat. This is because much of the wheat grown in the US is for export, and people in many other countries refuse to eat GMOs.
There are only a few vegetables that have any GMO varieties. Some have been tried and failed. All vegetable seed is non-GMO unless labeled, and when purchasing GMO seed, you have to sign waivers. When searching on line, try various labels: genetically modified, GM, genetically engineered, GE, transgenic.
Summer Squash and Zucchini
To avoid zucchini yellow mosaic virus and watermelon mottle virus in summer squash and zucchini, GM varieties were created, starting in 1995. When I researched GM squash varieties in July 2017 for an article I wrote, I found mention of ten summer squash and zucchini, but now there seem to be fewer. On the Bayer/Seminis website for their squash varieties, in 2017, these all helpfully had a “B” icon (Biotech). The names sound like B-movies: Conqueror III, Destiny III, Liberator III, Patriot II, Prelude II, XPT1832 III yellow squash and Judgement III, Justice III, SV0474YG, SV6009YG zucchini. The website has been updated, as have the variety offerings, and they are less prominently labeled. ZW-20 virus-resistant yellow crookneck squash is a current transgenic line.
In 2005, about 13% of the zucchini grown in the USA was genetically modified to resist three viruses; the zucchini is also grown in Canada (Johnson 2008).
Mexican researchers in 2004 wrote a paper Assessing the risk of releasing transgenic Cucurbita spp. in Mexico. Localities with native wild relatives of transgenic squash were at risk of the greatest trouble from cross pollination. The genetic legacy of ancient squash lineages was at risk. Gene flow between crops and their wild relatives was widely documented. The authors urged much caution about where and when GMO squash should be permitted.
GM squash also poses a risk that its virus genes or the proteins they produce could interact with other viruses to produce new diseases. And, as with any genetically engineered crop, the squash poses the risk that its new genes might cause it to spread and become difficult to control.
The USA extracts 90 % of its sugar “needs” from US-grown sugar beet and sugarcane. Of the domestically grown sugar, half comes from sugar beet, and half from sugarcane. After deregulation in 2005, sugar beet resistant to glyphosate (RoundUp) was extensively adopted in the USA. 95% of sugar beets grown in the US are GM. The sugar produced from GM sugar beets is highly refined and contains no DNA or protein—it is just sucrose. In 2008, the Animal and Plant Health Inspection Service (APHIS), a division of the USDA, performed a court-ordered environmental review of the modified seed and announced that there was no risk to other crops such as beets (beetroot) for fresh eating and pickling, or related crops such as Swiss chard.
Since 2010, at least 80% of papayas grown in Hawaii are GM, to get around the devastating problem of papaya ringspot virus.
The ‘Flavr Savr’ Tomato
Consumers in the northern regions of the U.S. rely on tomatoes shipped in from the South if they want fresh tomatoes beyond the summer. To survive shipping, tomatoes are picked at the “mature-green” stage. They have already absorbed all the vitamins and nutrients from the plant that they can, but have not started to ripen. To ripen the green tomatoes, they spend 3 to 4 days in rooms where ethylene gas is released, and are then shipped at temperatures not lower than 50 degrees, to preserve what flavor they have. These tomatoes are probably still a few days away from being ripe.
Calgene, a biotechnology company, developed a tomato with a gene that slows the softening process that happens with ripening. Pectin gives tomatoes their firmness. The pectin in ripening tomatoes becomes naturally degraded by an enzyme and the fruits soften, making them difficult to ship.
The scientists “reversed” the tomato softening gene and reintroduced it into the plants. Reducing that enzyme in tomatoes slows cell wall breakdown and keeps the fruit firmer for longer. In order to tell if their “Flavr Savr” gene was successfully inside the plants, scientists attached a gene that makes plants resistant to the antibiotic kanamycin. By exposing the plants to kanamycin, they could tell which plants had accepted the Flavr Savr gene. Once in a tomato plant, the Flavr Savr gene attaches itself to the gene activating the softening enzyme. When the Flavr Savr gene is there, the “softening” gene cannot give the necessary signals to produce the enzyme that destroys pectin.
The NewLeaf GM potato was brought to market by Monsanto in the late 1990s. It was developed incorporating Bacillus thuringiensis (Bt) bacteria to kill Colorado potato beetles. The target audience of fast food retailers rejected it and food processors ran into export problems. It was withdrawn from the market in 2001.
In 1998, a safety study (Ewen and Pusztai 1999) of GM potatoes with incorporated snowdrop bulb lectin (GNA) gene (Lectin acts as an insecticide), showed significant changes in the intestines of rats fed GM potatoes. The tested potatoes were not a commercial variety and not intended for human consumption, but the public were alarmed.
In 2010 Amflora was developed by BASF Plant Science for production of pure amylopectin starch for manufacturing waxy potato starch. It was approved for industrial use in the European Union in 2010, but was withdrawn in January 2012 due to rejection by farmers and consumers.
In 2011, BASF requested approval for its Fortuna potato as feed and food. The potato was made resistant to late blight by adding resistant genes that originate in the Mexican wild potato Solanum bulbocastanum. In February 2013, BASF withdrew its application.
In 2014, the USDA approved a GM potato type, Innate, developed by the J. R. Simplot Company that contained 10 genetic modifications that prevent bruising and produce less (carcinogenic) acrylamide when fried. The modification uses RNA interference (deactivating genes already present), rather than introducing genetic material from other plants or animals. Ranger Russet, Russet Burbank, and Atlantic potatoes are examples of varieties using this technology. McDonald’s announced that they have ruled out using Innate.
In 2017 scientists in Bangladesh developed a GM variety of potato resistant to late blight.
In February 2015 Arctic Apples became the first GM apple approved for sale in the US. RNA interference is used to reduce the activity of polyphenol oxidase, preventing the fruit from browning.
In April 2016, a white button mushroom (Agaricus bisporus), genetically modified using the CRISPR technique, received the go-ahead, as the USDA considers it exempt because the editing process did not involve the introduction of foreign DNA, just deletion from a gene coding for an enzyme that causes browning, reducing the level of that enzyme by 30%.
The Problems with GMOs
When GM varieties are planted on a commercial scale, resistant weeds and pests can evolve. The emergence of resistant insects can negate the effects of a Bt GMO. Also, if herbicide spraying becomes more frequent on herbicide-tolerant GMO varieties, weeds can develop resistance to the herbicide. This can cause an increase in herbicide use or an increase in the amount and types of herbicides used on crop plants. It is not a coincidence that herbicide producers are behind this research.
Further investigation is needed to learn if residues from herbicide- or pest-resistant plants could harm soil organisms. Another uncertainty is whether the pest-resistance of GE crops can cross to related weeds, creating resistant weeds. Possibly insect-resistant plants can cause increased death rates to one specific pest, decreasing competition and allowing previously minor pests to become a major problem. Also, it could cause the pests to move to another plant that had been unthreatened. A study of Bt crops showed that beneficial insects are also exposed to harmful quantities of Bt. It is possible for the effects to reach further up the food chain to affect crops and animals eaten by humans.
It is possible that virus-resistance can lead to new viruses and new diseases emerging. Naturally occurring viruses can recombine with viral fragments, forming new viruses.
The main concerns about adverse effects of GM foods on human health are the transfer of antibiotic resistance, toxicity and abnormal immune responses. A known allergen may transfer from a GM crop into a non-allergenic crop and create a new allergen. Patients allergic to Brazil nuts and not to soybeans showed an allergic response towards GM soybeans.
A Law on our Side
In January 2022 the National Bioengineered Food Disclosure Standard became mandatory. The new Standard requires food manufacturers, importers, and other entities that label foods for retail sale to disclose information about BE food and BE food ingredients. This rule is intended to provide a uniform national standard for providing information to consumers about the BE status of foods. The Final Rule was published in December 2018
The BE Food Disclosure must be placed on either the main information panel on the label, or an alternate panel “likely to be seen by a consumer under ordinary shopping conditions.” For bulk foods, retailers are responsible for displaying the BE food disclosure on or near the bulk item. Now you know what to look for!
Book Review: Grow More Food, a Vegetable Gardener’s Guide to Getting the Biggest Harvest Possible from a Space of Any Size, by Colin McCrate and Brad Halm. Storey Publishing, 2022, 300 pages, diagrams, $24.95
This book, Grow More Food, is an updated version of the authors’ 2015 book, High Yield Vegetable Gardening. I have been a big fan of that book since it was published. This book has much the same content but is a larger format with color photos and a larger print size.
Some of the content has been rearranged into a different, more logical, order, (athough a good index does make all topics findable). Some of the more technical or professional terms have been changed from the earlier book. “High yield” has become “productive”. The real or fictional example gardeners have almost disappeared, although drawings of their gardens live on.
If you have High Yield Vegetable Gardening and like it a lot, as I do, you probably don’t need to buy Grow More Food, unless as a gift for a friend, or if you are going to relegate the old version to the greenhouse or shed as a quick reference work. You may like to have the bigger print and the more informative and inspiring color photos in your house for periods of longer contemplation and planning. The new one, however, does not have the lay-flat spiral binding of the old one. The book is definitely a good one to keep on hand, in one version or the other.
The authors founded Seattle Urban Farm Company in 2007, and have been running it since, helping more people grow food. Their focus is to ‘find joy in the simple pleasure of doing a little better each season.” Here they are bringing proven professional techniques for bigger harvests to vegetable gardeners on any scale. The information is presented very clearly, without jargon, so that home gardeners will easily benefit. As I said in my review of High Yield Vegetable Gardening, this also provides newbie professional growers with solid information on techniques that work, without the need to understand everything at once.
These are gardeners after my own heart. Here are details you will benefit from knowing and putting into practice, which are not found in many gardening books: interpreting and using soil tests, choosing onion varieties that work at your latitude, succession planting for continuous harvests, flame-weeding, making soil block mix of the right consistency, dealing with salt build-up in greenhouse soils, minimizing nitrate accumulation in winter greens under cover. There are lots of useful charts.
This edition has more emphasis on building and maintaining good soil, and includes sidebars that dig deep into particular topics such as providing onion flavors all year, making space dedicated to perennial vegetables, converting farm-scale soil amendment rates to garden-scale ones, setting transplants at different depths, hand pollination of cucurbits, and the role of ethylene in crop storage.
The sequence of topics starts with clarifying your garden priorities, planning and record keeping: “It’s no exaggeration to say that a detailed garden plan alone can double or triple the productivity of a garden.” There’s help in choosing the right size of garden for your needs, experience and available time. Next, create a map or drawing of the garden site, including buildings, paving and trees, and consider which crops to grow. The chart of annual crops includes days to harvest and whether to direct sow or transplant. This enables gardeners to compare short-season crops, long-season crops and those in between, to plan food for the whole season; and sequential follow-on crops to make best use of all your space.
Once you’ve figured which crops to grow, how much of each to plant, when (and how often) to plant them, you can create your planting calendar. There are options for format, and a real-life example with arugula. This is followed with a sample section of a planting calendar with harvest tracker and room for notes for next year.
The next big question is “Where?” Make a map of your garden and think about a crop rotation to help you get the best yields by avoiding planting the same crop in the same place each year. A two-year rotation simply has two groups of crops and two beds or plots that flip each year. A three-year rotation can consider which crops need heavy feeding and follow two years of heavy feeders with one of light feeders. Also, if you don’t have soil-borne diseases, consider the counter-intuitive idea of following brassicas with brassicas in the spring and fall of a year, and avoiding brassicas in that bed for the next two or three years. For gardeners like me who grow a lot of brassicas, this makes planning a rotation easier. As well as an overall map of the whole garden, make a planting schedule for each bed, with space to write things down.
A pest and disease management log is another useful piece of record-keeping. It will remind you when to be on the lookout for particular problems, and what strategies worked for you previously. A garden log or diary with entries each day you garden can end with a To-Do list, including things to buy, and watch for.
And that’s just the first part of five. The second is about building healthy soil, providing a diverse ecosystem, high nutrient-level crops and big harvests. There’s information on making boxed beds, if you want to go in that direction, or lasagna beds, where organic materials are piled in layers, and tilled beds incorporating amendments. Tarping (covering soil with tarps to smother weeds) is also discussed. Mulches for pathways are compared. There is a very clear description of taking, submitting and understanding results from soil tests, accompanied by an annotated soil report.
There are clear instructions on making quality compost, buying compost, improving soil with cover crops, and mulching over winter. This chapter includes a manageable chart of “beginner” cover crops (buckwheat, four clovers, peas, vetch, mustard, oats and winter rye). Then comes the weed-reduction chapter. Strategies include dealing with weeds while they are small and seed-free, hoeing (photos of various types, with pros and cons), flaming (good safety tips here!), tarping and mulch.
Part 3 is Get to Know Your Plants – “Grow More Food by Planting the Right Varieties at the Right Time with the Best Care.” Smart gardening, with no wasted effort. Choose suitable varieties (open pollinated ones and hybrids) to match your climate and your goals. Order sensible quantities, store leftovers carefully (cool, dry, dark, airtight, mouse-proof) for use next year. There’s a two-page chart of Seed Lifespan, including parsnips and peanuts, something for every climate. Seed treatments to improve yields are covered, including soaking, scarification and inoculation.
The chapter on transplanting and direct seeding advises on which technique works for which crops. There’s information about supporting plants, from hilling up with soil, to making trellises. Supplemental fertilizers (during the growing season) are useful for some crops, not needed for others (the lists are in the book). The general theme is that heavy feeders and fast-growing crops will benefit. There’s an interesting section on pruning for production, including for good air circulation; for delaying bolting; for encouraging earlier harvests (by root pruning); and removing late flowers to focus energy on maturing fruits already formed.
The goal of managing pests and diseases is not to eliminate them all, but to control levels by cooperating with and stimulating natural processes that restore balance. This process starts with preventing problems, and ramps up if this does not succeed well enough. Develop good soil; attract beneficial insects; use rowcover or netting to keep expected insect pests from vulnerable crops; use deterrent sprays such a baking soda, hot pepper, garlic, kaolin clay for various problems; bring in beneficial organisms.
To nip any problems in the bud, it is important to monitor or scout your gardens at least once a week, looking for problems. Distinguish problems caused by extreme temperatures and water shortage from those caused by pests and diseases. Find good ID resources. You may be able to hand pick or trap enough pests to make the difference between a damaging outbreak and a trivial level. The authors explain why it is unwise to rush for the sprayer. Sprays are a last resort, even organic ones, because they may kill unintended insects, and they leave some of the pests alive to develop resistance, making that spray ineffective in the long run. There’s a two-page chart for pest and disease management strategies.
Part 4 is entitled Create Efficient Systems. It describes how to use your resources well, so time, money and space are not wasted, and you get the best from your efforts. Set up a home nursery to grow your own transplants, and plant the varieties you want in the quantities you want, to fit your schedule. Here are details on light intensity and where on the color spectrum the light should fall. You may be surprised just how much light plants need. For overall plant growth, general full-spectrum lights are just fine for a nursery, where the plants are headed outdoors to the natural source. Growing plants to maturity indoors is another (costly) matter.
The photos on making soil blocks are very helpful, and it’s a topic not covered in many places. Various types of plant container are covered. Making your own seed-starting schedule is explained. There’s info on propagating from cuttings, grafting with silicone clips, and watering or misting tiny plants. The next chapter covers irrigation of more kinds: drip systems (good description and photos for newbies) and sprinklers (including oscillating lawn-type sprinklers, wobblers, impact sprinklers and microsprinklers). This section will clear up a lot of confusion. Whichever you choose, make yourself an irrigation map, helping ensure you run pipelines and hoses along the best route, and set up sensible zones. Designs that minimize the need to move equipment around during the growing season will preserve your sanity and sense of well-being.
Part 5 is Extend and Expand the Harvest. This includes storage. Good techniques and timely harvesting let you get the most food from your crops, and eat them at peak quality and flavor. Extending the growing season includes starting as early as possible, finishing as late as possible, helping crops get through hot weather as well as cold, and planting successions to give you a seamless harvest through the growing season. Try crops you have not grown before.
The section on choosing protective structures will help you think about the pros and cons, costs and benefits of low tunnels (with rowcover or clear plastic), cold frames, greenhouses, high tunnels (also called hoophouses), and combinations of low tunnels inside high tunnels. If you are undecided on this topic, Grow More Food could save you from buying the wrong thing and wasting many times its cover price. And it could save you the big disappointment of not getting the harvests you hoped for. Consider not just cost but also ease of use (let’s enjoy our gardening!), suitability for your climate, and gained productivity. Glass greenhouses and greenhouse heating are often not cost-effective, and heating brings environmental costs too.
When weighing up design features, do the math for your own situation. I dislike the “comb” greenhouse bed design because it doesn’t work so well with drip tape. The authors say it maximizes usable space. But the difference is very small and the disadvantages are several. You lose the staging area of the lengthwise beds design. Many gardening books neglect methods of summer cooling, but the climate emergency is upon us. Here you will find good ideas about shade cloth and using overhead irrigation for cooling.
The next chapter is about timely harvesting and successful storage. Remember when planning your garden to think about how much food you can use, including not just how much your household can eat, but also how much time you have each week for harvesting and storage. There is a good discussion about becoming a skilled harvester. For each likely crop there is a short description of which part to harvest, and how to recognize maturity.
Next is a section on harvesting “hidden” crops – extra harvests form your garden: weeds, less usual parts of crop plants, such as flowers, garlic scapes, carrot leaves, pea shoots and tendrils, and sweet potato leaves. You can harvest more food from the same plants by choosing varieties that provide multiple harvests (loose leaf crops, broccoli side shoots, turnip and beet greens and roots).
There’s a bit on washing crops, and food safety. Then harvesting for maximum freshness and quality, and storage, short and long term. Not everything should be refrigerated! Onions, garlic, winter squash, potatoes and sweet potatoes need to be cured before long-term storage. Be sure to get the details right, or you could have big losses. There is a 4-page chart of storage conditions for various crops. Although I agree with the authors on almost everything they write, I wouldn’t wipe down winter squash with bleach. I’ve never found it necessary.
At the end of the book are worksheets you can photocopy and use. Or you can download them from Seattle Urban Farm. They include a Crop Amount Worksheet, Planting Calendar Worksheet, Planting Dates Worksheet, and Garden Planning Chart. The website also has sample log pages for a specific bed, for the garden as a whole, a pest and disease management log, harvest log, and planting calendar with harvest tracking.
There is a resource section and I was particularly happy to find two resources for non-toxic wood preservatives for garden use. The index looks very thorough – 21 columns for 300 pages.
The Seattle Urban Farm Company has a blog and a podcast, and their Projects page will give you lots of ideas on garden layout and design. Their shop sells training sessions, webinars, and individual coaching.
We’ve reached mid-May, the time of year to transplant our okra. Okra is a tropical annual in the mallow family, and is widely adapted where the frost-free season is long enough. Okra is heat- and drought-tolerant and has few serious pests or diseases. Those in hot climates will need to deal with its exuberant growth in mid-summer. Those in cold climates should choose fast-maturing varieties and transplant into black plastic. In areas with cold nights, okra can only be grown in a hoophouse.
We like Cow Horn okra from Southern Exposure Seed Exchange, which gives good yields and sturdy plants in our zone 7a climate. It is one of a few varieties that can grow relatively large pods without their becoming tough. We are sometimes not good at finding all the pods when harvesting, so it is an advantage to us if they are still good to eat when bigger than normal. SESE has an Okra Growing Guide.
Spineless (easy to harvest) varieties include Clemson Spineless (56 days), and Evertender (50 days). Red-podded varieties include Burmese (58 days), a high-yielding dwarf heirloom, and Red Burgundy (49 days), reported to do well in “cooler” areas, although it will not do much until day time temperatures reach 80°F (27°C).
Crop Requirements and Yield
Okra does best in well-drained, fertile, loamy soils with high organic matter. Wet clay soils can drown the plants. It grows best with a pH between 6.5 and 7.0, although as high as 7.6 is still OK.
5 gmsows 50’ (15 m) at 6” (15 cm) spacing. Average yields are about 50-100 lb/100’ (7.6-15 kg/10 m). We grow 90’ (27 m) for 100 people, which provides enough for some pickling too.
According to Rodale’s 600 Answers, germination speed can be improved by freezing the seed overnight, then soaking in hot water for ½-1 hour before sowing. It needs to be warm enough to get your seed germinated: you can soak the seed for 8 hours in water at 88°F (31°C).
When we direct sow, we “station-sow” – we put three seeds ½-1” (1-2.5 cm) deep at each spot where we want a plant to grow. We do this on May 1, with rowcover, as this is around our last frost date, and we want to avoid disasters! Direct sow once the soil temperature averages 65°F (20°C), 3-4 weeks after last frost.
When seedlings have 3-4 leaves, we thin to the strongest seedling. Okra is sturdier if direct sown, rather than transplanted, but you work with the climate you’ve got!
Usually we transplant, especially if we are intercropping. For transplants we sow April 15, using soil blocks or Winstrip 50-cell flats. I was amazed to learn that at 6″ (15 cm) tall, plants could have taproots three times as long! At full maturity, the tap root could be 4½ ft (1.4 m). To avoid stunting the taproot, get the small plants in the ground as soon as you can, carefully.
We transplant 3-4 week old starts – a plant with 3 or 4 leaves is ideal – at 18” (45 cm) spacing in a single row down the middle of a bed. We transplant May 11, 10 days later than the direct-sowing date. In the past we used wider in-row spacing, but found we could get a higher yield with the “hedge-like” closer spacing.
Some growers plant as close as 6” (15 cm) in the row, with 5’ (1.5m) between rows, or plant double rows with 12” (30 cm) between plants, and wider spacing between the beds. Thick planting requires very fertile soil, and risks diseases from poor air circulation. Wide spacing can lead to heavily branched plants, and more pods per plant, but not necessarily more pods for a given area. It may lead to a later start to the harvest, as flowering is delayed while the plant grows bigger.
Okra is slow-growing until hot weather arrives. We sometimes take advantage of this and its upright growth habit to transplant okra into a bed of early cabbage. We transplant cabbage in two rows along a 4’ (1.2 m) bed on March 10 and the okra in a single row down the middle on May 11. We mulch the cabbage, which has the disadvantage for the okra, of cooling the soil, so don’t try this if direct sowing! At first the cabbages are relatively small, and the okra uses the open space in the middle of the bed. As the plants grow, we remove outer leaves of the cabbage that might overshadow the okra. Finally, we harvest the cabbage and leave the okra to grow to full size. This method saves space, and efficiently uses our time to help two crops with one weeding.
This post is part of what I have written about okra in my book Sustainable Market Farming. Buy the book to read the rest, including crop rotations, pests and diseases, harvesting and post-harvest care of okra.
The Whole Okra
See my review of Chris Smith’s book The Whole Okra. Chris has grown 125 varieties of okra, and still counting, and cooked it in many different recipes. His book includes using the oil from the seeds, eating the leaves; making okra-stem drinking straws, okra seed tempeh, okra marshmallow delights; okra history and geography, medical and industrial uses and so much more. Here are instructions for freezing the sudden glut of okra that often arrives at some point in the summer, pickling (both by fermenting and with vinegar), drying (best when strung on dental floss). Best of all are the okra chips. Chris has a video of taste testing on YouTube, https://www.youtube.com/watch?v=sAy0pouxlME