Solarization and crop choices to fight nematodes

Solarizing to combat nematodes. Photo Pam Dawling

Solarization

Solarization is a method of killing pests, diseases and weed seeds near the surface of the soil by covering the soil with clear plastic for six weeks or more in hot weather. We use this method to help control nematodes in our hoophouse. Nematodes are only active in warm weather, and we have not had problems with them outdoors, but of course, it’s warmer in the hoophouse!

I’ve written before about solarization to fight nematodes in our hoophouse.

In my Book Review: The Organic No-Till Farming Revolution: High Production Methods for Small-Scale Farmers, Andrew Mefferd, I wrote a little about solarizing:

“Solarization uses clear plastic (old hoophouse plastic is ideal). In a summer hoophouse, solarization can be as quick as 24 hours, Andrew says. When we’ve done this, one of our goals was to kill nematodes and fungal diseases, not just weeds, so we waited a few weeks. Outdoors it takes several weeks. You can see when the weeds are dead. Bryan O’Hara poked a thermometer probe through solarization plastic and found a 50F degree (28C) difference between the outside air and the soil immediately under the plastic; a 10F (6C) difference at 1″ (2.5 cm) deep and little temperature gain lower than that. Solarization does not kill all the soil life!”

Extension offers Solarization and Tarping for Weed Management on Organic Vegetable Farms in the Northeast USA which can, of course, be modified for those of us in other regions.

Solarizing to combat nematodes: Step on a spade to push the plastic down into a slot in the soil.
Photo Pam Dawling

Nematodes

I’ve written here before about our struggles with root knot nematodes in our hoophouse, and you can read everything I know about nematodes in the Year-Round Hoophouse.

My article on nematodes in Growing for Market  in November 2014 describes our discovery of the beasties and our first attempts to deal with them.

My most thorough blogpost about nematodes was for Mother Earth News  Managing Nematodes in the Hoophouse.

Cucumber roots with nematodes (see circles).
Photo Pam Dawling

My post Good news – great hoeing weather! Bad news – more nematodes in the hoophouse August 2014 includes a photo of our first attempt at solarizing – a  bit of a How Not To!

There is info on dealing with nematodes from Garry Ross in Hawaii, where nematodes are a fact of daily life, in my post Cold weather, snow, thinking about nematodes from February 2015.

Cover Crop Choices

French marigolds and sesame to deter Root Knot nematodes in our hoophouse.
Photo Pam Dawling

In June this year I wrote about using marigolds, sesame, Iron and Clay cowpeas as nematode resistant cover crops. We’ve also used winter wheat, and white lupins. See Our Organic Integrated Pest Management . Other cover crops that suppress nematodes include some other OP French marigold varieties (but avoid Tangerine Gem or hybrid marigolds); chrysanthemum; black-eyed Susan; gaillardia (blanket flower, Indian blanket); oats; sesame/millet mix. We decided against sorghum-sudangrass (too big), winter rye (harder than wheat to incorporate by hand), bahiagrass, Bermuda grass (both invasive), castor bean and Crotolaria (sunnhemp) (both poisonous, although newer varieties of Crotolaria have lower toxin levels, and I’ve been rethinking my opposition to using that), partridge pea, California poppy (both require at least one full year of growth) and some obscure vetches that weren’t available locally. We might have included Pacific Gold mustard (B. juncea), if we’d found it in time. Don’t confuse this with Ida Gold Mustard, which kills weeds, and is susceptible to nematodes.

Food Crop Choices

 This list starts with the crops most resistant to Root Know Nematodes and ends with the most susceptible. I’ve included some “bookmarks” between categories, but it can also be read as a continuous list:

Scallions in our hoophouse in late November.
Photo Pam Dawling

Most resistant

Strawberries

Rhubarb

Onion (? not certain)

Corn

West Indian Gherkins

Horseradish

Asparagus

Jerusalem Artichokes

Globe Artichokes

Radishes in our hoophouse in February.
Photo Pam Dawling

Fairly Resistant

Ground Cherry

Some Sweet Potato varieties

Radishes (? not certain)

Rutabagas

Garlic, Leeks, Chives

Cress

Brassica juncea mustards

Brassica rapa var. japonica greens (? Uncertain)

Broccoli, Kale, Collards, Brussels Sprouts

Red Russian kale from Southern Exposure Seed Exchange in our hoophouse in March.
Photo Pam Dawling

Somewhat Susceptible:

Fall Turnips

Peas

Fall Spinach

Swiss Chard

Parsnips

New Zealand Spinach

Very Susceptible:

Lettuce

Cabbage

Cucumbers, Muskmelons, Watermelons, Squash, Pumpkins

Beans, Fava Beans, Soybeans

Okra

Beets

Carrots, Celery

Tomatoes, Eggplant, Peppers, Potatoes, Peanuts

Ruby Streaks, Golden Frills, Scarlet Frills juncea mustards, very resistant to root-knit nematodes.
Photo Pam Dawling

Nematode-resistant winter greens

 We came up with a collection of nematode-resistant winter greens, including radishes, Russian kales, Brassica juncea mustards (mostly salad greens like Ruby Streaks, Golden Frills, Scarlet Frills), and Brassica rapa var. japonica greens, mizuna and Yukina Savoy. We have since learned that Yukina Savoy is a Brassica rapa, not B. juncea as we thought, and that mizuna is Brassica rapa var. japonica with a less certain resistance, or perhaps Brassica rapa var. niposinica, or perhaps B.juncea after all (integrifolia type). We also grow scallions in the nematode-infested areas. Now I am looking for more nematode-resistant cold-weather greens.

Green mizuna in our hoophouse in November.
Photo Pam Dawling

This Year

After the winter greens this spring, we transplanted two beds of tomatoes, one each of peppers, squash and cucumbers, and put two beds into Iron and Clay cowpeas. The eastern ends where we had found evidence of nematodes, we transplanted French marigolds and sesame as stronger fighting forces.

When we pulled up the squash and cucumbers  we found no sign of nematodes on the roots. One of the tomato beds produced no sign either, but the other one did. Our first response was to sow Iron and Clay cowpeas instead of the planned soybeans, but before the plants were even 2” (5 cm) high, we decided to solarize that whole bed. We now have small patches of nematode infestation in almost every bed, calling for a more nimble approach to crop planning.

Brassica juncea mustards to try

According to Wikipedia, Brassica juncea cultivars can be divided into four major subgroups: integrifolia, juncea, napiformis, and tsatsai.  I did some searching for more B. juncea, especially large leafed ones. Some promising looking crops include these:

“Green-in-Snow” mustard, Serifon gai choi type Chinese Mustard, Suehlihung.

Serifon (Suehlihung, Green-in-Snow) mustard. Kitazawa Seeds

“Red-in-Snow” mustard (sorry, no details)

Osaka Purple Mustard. Fedco Seeds

Giant Red, Osaka Purple, Southern Giant Curled Mustards, all quite pungent

 

 

 

 

 

 

Horned Mustard. Wild Garden Seeds

Horned Mustard

 

 

 

Miike Giant mustard. Kitazawa Seeds

Miike Giant

 

 

 

 

Hatakena Mustard. Kitazawa Seeds

 

Hatakena

Yanagawa Takana.
Kitazawa Seeds

 

 

 

 

 

Yanagawa Takana broad leaved mustard

 

 

 

Wasabina baby leaf mustard (wasabi flavor). Kitazawa Seeds

 

Wasabina

Cooking Greens in August

 

The vine tips of sweet potatoes make good summer cooking greens.
Photo Bridget Aleshire

Cooking Greens to Harvest in Central Virginia in August

Chard leaves and sweet potato vine tips can be harvested here all month. It really isn’t the season for new cooking greens. We have cabbage in storage, to get us through the “dead center” of the summer, until we can start the fall green harvests. In late August we can start to harvest senposai, turnip thinnings, Yukina savoy, komatsuna, Maruba Santoh, pak choy, Tokyo Bekana. Turnip thinnings can make a tasty dish, if the small plants with marble-sized turnips are cooked together with their attached tops. Wash well, of course.

If we had grown them, we could harvest molokhia (Egyptian spinach, related to okra), manihot (aibika, also related to okra), and okra leaves themselves, if the Japanese beetles have left enough! See the special topic below for more on these.

Cooking Greens to Sow in Central Virginia in August

Fall broccoli patch.
Photo Kati Falger

We sow our fall brassicas weekly throughout late June and July – see the Special Topic for June for all the details. If we have had big trouble, we might need to resow some broccoli, cabbage, or Asian greens in August, but hopefully not. If we do need to resow this late, we choose only the fast maturing varieties, to make up for lost time.

Although sowing the fall greens in nursery seedbeds comes to an end, we are not slacking. August is our month to establish 6 beds of Vates kale. We use ProtekNet against flea beetles. Our method is a hybrid between direct sowing and transplanting. With over 2160 row ft (660m) to establish in the sometimes brutally hot and dry conditions, we would not want to transplant this number of plants. Direct sowing all at once would be impossible for us to keep sufficiently watered. We focus on two neighboring beds (720 row ft, 220m) at one time. We direct sow the two beds, cover with netting, and water by hand every day. In 4 days the seedlings will have emerged, and they can survive on less than daily watering after 6 days. So every 6 days we sow two beds. Our dates are August 4, 10, and 16. Sometimes we sow by hand, sometimes with the EarthWay seeder, with plate 1002-24. Our last date for this round of sowings is September 7.

On August 20 we revisit the first two beds and resow if the survival rate is really poor, or we plan to move plants around to fill gaps, if there are not too many. On August 24 we revisit the second two beds and resow sections if needed. On August 28 we revisit the last pair of beds sown. Our last date for resows is September 15. We only grow one variety outdoors, and we can use plants from any of the beds to fill out any other. We tackle this task when the plants are about 3-4 weeks old, in late August and early September. We eat the extra plants.

Vates kale.
Photo Nina Gentle

We grow Vates kale, a very cold-hardy dwarf Scotch curled type. I’d love to find a bigger equally-hardy curled variety, but I have not found any. We don’t rowcover our outdoor kale, so it needs to be very hardy. We tried rowcover one year, but it was a bother to deal with, and fibers of the rowcover caught in the curly leaves and we were not appreciated by the cooks.

For the second pair of beds, we often repurpose the first of our brassica seedling beds, as the broccoli, cabbage and Asian greens are all planted by then, the bed has clean soil, and netting and sticks at the ready.

Thinned turnip seedlings.
Photo Pam Dawling

We sow turnips from early August to mid-September, and beets from early August to late August, for both roots and greens. It is hard to get beets germinated in hot soil, but if you delay, they don’t have time to grow big roots before the cold weather. You can sow beets dry or presoak 1-2 hours (not longer, and not in too much water, as they easily drown); sow 1/2″-1″(1-2.5cm) deep, tamp the soil, keep the surface damp, water daily for the 4-6 days they take to emerge. We use netting for turnips, but not for beets, unless the grasshoppers are bad.

Young beets.
Photo Pam Dawling

It’s also possible in warmer areas to sow Swiss chard or leaf beet for a fall crop. This is a useful Plan B if some other crops have failed. The last planting date is ten weeks before frost. Our average first frost here is October 20. This is an average over the past 13 years. We can only sow chard until August 11 or so. It’s not that the first frost will kill the chard, far from it, but the frost date is an indicator of when growth starts to slow down.

Cooking Greens to Transplant in Central Virginia in August

Morris Heading collards.
Photo Kathryn Simmons

June is the time to prepare a plot for the fall broccoli and cabbage. July and August are the time for transplanting them. See the July cooking greens post for details of how we tackle this big transplanting job. In early August (if not done in late July) we transplant two beds of collards. By late August we want to really finish transplanting the fall broccoli, cabbage, and the kale from the August 4 sowing.

In week 7 of our fall greens schedule (the first week of August): We transplant week 4 sowings of senposai, Yukina Savoy, and anything we resowed in week 4. We also fill any gaps in week 4 transplantings (= week 1 sowings). Cover: hoop and net or rowcover.

In weeks 8 & 9 (the second and third weeks of August): We transplant anything we didn’t keep up with, and replacements in weeks 5 and 6 transplantings (weeks 2 & 3 sowings), Cover: hoop and net or rowcover.

Other Cooking Greens Tasks in Central Virginia in August

Broccoli undersown with clover.
Photo Nina Gentle

If things are on schedule and we haven’t needed to replace many casualties in the big brassica patch, we roll and store the covers, wheelhoe or till between the rows and weed. Then we undersow with a broadcast mix of mammoth red clover, white Ladino clover, and crimson clover. This will become our all-year green fallow next year.

August is our worst month for grasshoppers and crickets, so we watch for them and either use netting, or postpone sowings until the end of August.

To improve germination next month, we put spinach seeds in the freezer now, for at least two weeks.

No visible brassicas month comes to an end. To disrupt the lifecycle of the voracious harlequin bugs, we have only netted brassicas in our gardens from early July, when the last of our spring brassica crops get mowed down and disked in, and we sow seedling brassica crops under netting. When we transplant the young brassicas, we cover those all with netting or rowcover for a few weeks.

Special Cooking Greens Topic for August: More Unusual Hot Weather Cooking Greens

See Cooking Greens in July for details about the chenopods – amaranths, Aztec spinach, orach, Good King Henry, Magenta Lambsquarters, strawberry beet and also celosia. Many of these can be sown again in August to provide a succession of tender young greens. Here are some other hot weather greens. Like July’s unusual cooking greens, all the following are warm weather crops, so don’t try to grow these in early spring or into late fall. If sown in August, they can follow an earlier crop such as lettuce, peas, or early sowings of beans, squash or cucumbers.

Sweet Potato Leaves, Ipomoea batatas

Plant sweet potatoes for a fall root harvest, and get the bonus greens crop all summer! You can harvest the leaves and young shoots for cooking greens at any time during growth (just don’t take too much at once). For cooking ideas, find Water Spinach recipes and substitute sweet potato shoots. Chili and shrimp or peanut sauce feature in many recipes.

Water Spinach, Ipomoea aquatica; aka Kang Kong, Ong Choy, Phak Bung.

This tropical, semi-aquatic plant is cultivated for its tender shoots and leaves. It is easy to start from seed or you can root cuttings (roots show in 2-3 days) from bunches bought at an Asian supermarket. The long stems will readily root from the nodes. The leaves are quite large: 2”-6” by 1”-3” (5-15 by 2.5-7.5 cm). The tender shoots are cooked along with the leaves. The flowers look just like sweet potato flowers.  It is a USDA Class A noxious weed in Hawai’i, Florida and California, where it has escaped into the wild. Check your state regulations, and grow this in some sort of container to be sure.  A safer bet is to eat sweet potato greens instead.

New Zealand Spinach (Tetragonia expansa, Tetragonia tetragonioides)

New Zealand Spinach tolerates heat and drought beautifully. It is salt-tolerant and will even grow in sand. This sprawling bushy plant with small, succulent, triangular leaves is generally free of pests. The flavor is very mild, not particularly like spinach, despite the name.

Soak the seed for 4-24 hours before planting to speed germination – it can take 8 weeks to emerge. Direct-sow from mid to late spring (bean-planting time), or sow indoors about 6 weeks before last frost. It takes 65-75 days to maturity. Thin to at least 6” (15 cm) apart. It needs hot weather to really get going.

Regular trimming encourages lush growth. Use scissors to harvest the shoot tips. Picking the individual triangular leaves would be tedious, as they are fairly small.

Like true spinach, Tetragonia leaves contain oxalic acid, so should be eaten in moderation, mixed with other greens.

It can become invasive as it sets seed readily. This happened to me the first year I grew it – I thought some self-sowing would be a good thing, but I seriously under-estimated both the number of seedlings I’d get and the distance the seeds could ping.

Red Malabar Spinach.
Photo Southern Exposure Seed Exchange
Malabar Spinach (Basella alba, Basella rubra)

This tropical plant is from Asia and Africa.. The gorgeous twining vines are very tall, so they need to be trellised or caged, which has the bonus of keeping the leaves clean. One technique is to plant them on the pea trellises and let them take over as the peas finish. There is a green-leaved Malabar spinach with red stems, but the red is exceptionally beautiful, so I recommend that one. This crop also does well in partial shade.

The crinkled heart-shaped leaves look like spinach, although more crisp, glossy, and slightly succulent. They have a flavor similar to beet greens. They stay mild and maintain healthy growth all summer. Bees love the blossoms.

Sow in late spring, when it’s warm enough for beans. Germination is slow – even at their preferred temperature of 70-80°F (21-27°C) the seeds can take 10-14 days. Soaking the seed in warm water before sowing may help. You could start them indoors and transplant at 3-6 weeks old, or older, as much as 8” (20 cm) tall. Plant or thin to at least 6” (15 cm) apart and, to promote a more branched plant, pinch out the central shoot after the second set of leaves.

The plants need 60-90 days to maturity, and then will produce an abundance of moderately small leaves all summer, until cut down by the slightest frost. Harvest individual leaves as needed, or cut the vine tips to use as cooking greens. (Young leaves can be added to salad mixes.) Lop the vines when they are as tall as you want to deal with – they will regrow even if severely cut back.

The taste is slightly seaweedy (it’s also known as “land kelp”), and the texture is somewhat mucilaginous in the way that okra is. It can be eaten raw if you like the chewy texture. It is excellent for stir-fries or for thickening summer soups and stews. William Woys Weaver reports that it cooks beautifully in a microwave, but on a hot day eat the refreshing leaves raw. The leaves store for up to two weeks in the refrigerator.

This crop is pest-free, but watch out for the staining properties of the black berries (good for dying fabric). Malabar spinach does self-sow, but this is only likely to be a problem for those in tropical climates

Okra leaves
Yes, okra ;eaves are edible.
Photo Bridget Aleshire

Yes, okra leaves are edible. See Chris Smith’s amazing book The Whole Okra

Egyptian Spinach, Corchorus olitorius (Jute, related to okra)

Aka Melo Khiya,  Molokheiya, Molokhia and similar attempts to render the Arabic name in our alphabet. This  Arabic summer cooking green grows well in Virginia, North Carolina, Florida, Texas and everywhere with hot summers.

This versatile, continuous-harvest vegetable can survive both dry and wet conditions in warm or hot weather. GrowerJim has good details.

Only the small leaves are cooked and eaten. The dried leaves can be used to thicken soups or for tea. It’s not a vegetable to be eaten alone in big cooked heaps – it’s just too mucilaginous.

Jute fiber is extracted from the mature plants, suggesting a) don’t try to eat over-mature plants, and b) paper-making and various fiber arts could be in your future.

Depending on your climate and preferences, you can direct sow fairly heavily and thin, or start seeds in flats and transplant 12″ (30 cm) apart in all directions. Plant after danger of frost is past and the soil is warming steadily. Egyptian Spinach likes full sun, warm to hot weather and steady moisture – mulch will help keep the soil moist.

It takes 70 days to maturity, then holds well in the field, providing several cuttings. If you prefer to harvest the whole plant, succession-sow for future supplies. Continue to give compost or nutrients throughout the season, to encourage tender new growth.

It grows 2’-3′ (60-90 cm) tall or more, and then bears yellow flowers if you don’t keep it clipped back. The flowers are followed by seed pods which are edible and tasty when young, with more flavor than the leaves.

The mature seeds can be saved for replanting. Seed is available from Sandhill Preservation and  Bountiful Gardens (who reassure buyers that the seed is naturally green in color and is not treated.)

Manihot (aibika, Sunset hibiscus, also related to okra) Abelmoschus manihot – (L.)Medik.

It is a hardy perennial in US zones 8-11. Green Harvest has growing information. Plants for a Future also. Seeds are sold by Monticello as an ornamental, but Floral Encounters say: “However the importance of this plant is that it is one of the world’s most nutritious leafy vegetables because of its high protein content.”

Squash leaves and shoots, Cucurbita spp.

If your squash are being too rambunctious, or you are thinning a row a bit late and have sizeable plants, consider a harvest of vine tips and leaves. Or grow some just for this purpose, if you need a quick-growing summer green with novelty appeal. Stir-fry or gently braise – good with eggs for breakfast, says Ira Wallace at Southern Exposure Seed Exchange.

Blackeye peas and other crowder peas:

The tips and leaves are edible. Garden Betty writes about many of these less usual greens, from a salad perspective, in Summer-Lovin’ Salad Greens

 

Modern Homesteading Interview, Things I’ve Changed My Mind On

Hoophouse squash, tomatoes, and cucumbers.
Photo Alexis Yamashito

In April I did a pleasant phone interview with Harold Thornbro of the Modern Homesteading Podcast  about how year round gardening in a hoophouse can increase yields and the quality of vegetables and extend the growing season.

You can listen to it here:

https://www.stitcher.com/podcast/modern-homesteading-podcast/e/60326060?autoplay=true

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The rest of this post is about the agricultural things I’ve changed my mind on in recent years.

Sowing Leeks
Leek seedlings growing in an outdoor nursery bed.
Photo Kathryn Simmons

The first one that comes to mind is where and how to sow leeks. In Sustainable Market Farming I describe sowing leeks in outdoor nursery seedbeds. We grow leeks for eating from October to March, so even though leeks grow very slowly and need 12 weeks to transplant size, we don’t need to sow them super early in the year. Also because they are so cold-hardy, they don’t need greenhouse conditions. To save greenhouse space, and the bother of watering so many flats, we took to sowing them outdoors. To make this work, you do need weed-free beds. Leeks compete poorly with weeds. Sometimes things went wrong. One year someone decided to “seed-bomb” the fresh bed with poppy seeds. Weeding those tiny leek seedlings was torture! Another time, an overenthusiastic worker ran our new exciting wheel hoe too far onto the bed and eradicated part of a row.

Leek seedlings in flats in April.
Photo Pam Dawling

One year the leek seedling bed wasn’t ready in time to sow, and we sowed rows of seeds in a coldframe, after removing the winter spinach (or maybe we were still growing lettuce in the coldframes then.) This worked well. The next year we tried sowing the seeds in 4” (10cm) deep flats, and putting the flats into the coldframes right away (rather than germinating them in the greenhouse). Still no wasted greenhouse space! On very cold nights, we cover the coldframes, so it was a bit warmer than if we’d just sowed directly into an outdoor bed. The plants grew a bit quicker and we realized we didn’t need to start so early. They were easier to take to the field in the flats, compared to digging up the starts and carrying them in little buckets with water. We had reduced losses of seedlings, so we reduced the amount of seed sown in future years. It’s an easier system, with a more satisfying success rate.

Sunnhemp as a Cover Crop
Sunnhemp cover crop at Nourishing Acres Farm, NC.
Photo Pam Dawling

 Sunnhemp (Crotalaria juncea) is a warm weather leguminous cover crop that I’ve been admiring at various farms in the Southeast in recent years. I’ve been thinking it would be valuable ion our hoophouse and in our gardens. It fights root knot nematodes! I mentioned it recently at a crew meeting, only to be reminded that I previously spoke against growing it as the seed is poisonous! I’d completely forgotten my earlier opinion!

This summer cover crop can grow to 6’ (2m) in 60 days. It thrives in heat, tolerates drought, fixes nitrogen, suppresses nematodes, makes deep roots that pull nutrients from deep in the soil, and it dies with frost. It sounds fantastic, I really want to try it!  It looks a bit like small sunflowers, and according to Southern Exposure Seed Exchange  it  won’t make mature seed above 28 degrees N latitude , so won’t become a self-sowing invasive  in Virginia. Sow in rows 2’-3’ (0.6-1m) apart. If it gets too big, mow when plants reach 5’-8’ (1.5-2.5m) to prevent the stalks from becoming tough and hard to deal with. ¼ lb sows 250 sq ft. (¼ lb = 114 g, 250 sq ft = 23.2m2)

Sowing Sweet Corn
Young sweet corn with a sprinkler for overhead watering.
Photo Bridget Aleshire

I mentioned earlier here, that I’ve changed my mind about the necessity to put up ropes over corn seed rows to keep the crows off. I suppose there are fewer crows these days, sigh. Not needing the ropes makes the benefits of sowing with the seeder greater than the benefits of sowing by hand, so long as we can irrigate sufficiently to get the seed germinated. When we sowed by hand we watered the furrows generously, which meant we did not need to water again until after the seedlings emerged. If we hit a serious drought, the old method could still be best. Overhead watering does germinate lots of weeds, including in the wide spaces between the corn rows, so we need to factor in the extra hoeing or tilling when we weigh up the pros and cons. So, I’m a “situational convert” on this question!

How to Kill Striped Cucumber Beetles
Striped cucumber beetle in squash flower.
Photo Pam Dawling

I wrote about these beasties here. We handpick the beetles in the hoophouse squash flowers, hoping to deal with the early generation and reduce future numbers. One year we had our first outdoor squash bed very close to the hoophouse and the beetles moved there. In desperation I used Spinosad, an organically approved pesticide. It is a rather general pesticide, and harms bees, so I carefully sprayed late in the day and covered the row with netting to keep bees off. It worked brilliantly, taking a fraction of the time that daily handpicking takes. I became a convert to that method, but no one else on the crew did, so we went back to hand-picking.

Pruning Tomatoes
Hoophouse tomatoes in early May
Photo Bridget Aleshire

I used to maintain that life is too short to prune tomatoes, which grow at a rapid rate in our climate, and get fungal diseases, necessitating sowing succession crops. The past couple of years I have removed lower leaves touching the soil, and this year I reduced the sideshoots on our hoophouse tomatoes, which are grown as an early crop here.(We’re about to pull them up in early August, as the outdoor ones are now providing enough). I do think we got fewer fungal diseases, and the diseases started later compared to other years, so I am now convinced that removing the lower leaves is very worthwhile. We also got bigger fruit this year, which logically fits with reducing the foliage some amount.

Is There Such a Thing as Too Much Compost?
Too much compost?? A commercial compost windrow turner.
Photo by Pam Dawling

I used to think the more compost the better. Now I am more aware that compost adds to the phosphorus level in the soil. I wrote about that here. I am not as alarmist as some people about high P in our situation, but I do now think it is worth paying attention and not letting the levels build too fast. I have got more enthusiastic about growing cover crops at every opportunity, and finding legumes to include in cover crop mixtures at every time of year (see above about sunnhemp). I was already a cover crop enthusiast, but as my experience increased, I got my mind round more possibilities.

Using Plastics
Rolling biodegradable plastic mulch by hand
Photo Wren Vile

In my youth I was anti-plastic, If I were growing food just to feed myself, I’d probably still find ways to avoid almost all plastics, but growing on a commercial/professional scale (and getting older) has led me to appreciate plastics. I still don’t want to do plastic mulch, except the biodegradable kind, but I’ve come to accept durable light weight plastics for their benefits. Drip tape saves do much water, reduces weed growth. Plastic pots and flats are so much easier to lift! I do still pay attention and try to make plastics last a long time, and frequently salvage plastic containers others discard. I’m awed by the possibilities of silage tarps or old advertising banners, to keep down weeds without tilling and pre-germinate weed seeds so that when the covers are removed, few weeds grow. This was called by the awkward name of “occultation”, but is now more often referred to in English as tarping.

Hornworms

Lastly, I have a post on Mother Earth News Organic Gardening about hornworms, but you read it here first!

Book Review: Dale Strickler: The Drought Resilient Farm

Book Review: Dale Strickler: The Drought Resilient Farm, Practical Strategies for Drought Resilience on Farm and Ranch.

Storey Publishing, June 2018.

200 pages, color photos and drawings throughout, $24.95

We all need to read more books like this, to prepare for climate chaos and global heating. Alone, we can’t control how much it rains, or when, but we can improve our farming so that rain penetrates deep into the soil, is stored there and is able to keep plants and livestock alive through dry times. The author farms and ranches cattle in Kansas, using less than 4 acre inches of rain per year. This book is mostly addressed to livestock farmers, not vegetable growers like me. I skimmed some sections, although not much, as the same principles of caring for the soil apply to all farmers. This book is not about Organic Farming. Selective use of herbicides is advocated. But you decide. Selectively graze this book, taking only what you like!

[Oh why are books on sustainable agriculture in the US printed in China?]

The first part of the book is about creating a water-efficient soil with three approaches: getting more water into the soil; keeping water in the soil for longer; and helping plants get more of that water. The second part of the book is about providing for livestock: ensuring a reliable water supply; creating drought-tolerant pastures; providing emergency forage in a drought; and livestock decisions after a drought.

Part 3 of this very practical book is Looking to the Future, and includes water-efficient agriculture for semi-arid regions. There are resources for further reading, metric conversion charts and a glossary, and of course an index (without which no practical book is actually practical!) Buy this book to get the checklist of actions to take to prepare for future droughts, and cope with them as they occur.Ken Burns’ documentary The Dust Bowl should be required viewing, says Dale Strickler. We need to learn from history. Dale learned as a young man that the fantastic corn yields in Iowa were not due to that state having more rain than Kansas, but to the better soils. He also learned it is possible to get better yields on less rain. Poor soils are unable to hold onto the rain they do get. And this is something we can do something about. Dale increased his soil’s ability to hold water from 3” in 18” depth to 12” in the much-improved 6 ft depth after 11 years. Yes it takes time – start yesterday! The three key parts of this feat are:

  1. Get the water in (not running off)
  2. Keep it stored in the soil
  3. Ensure the plant roots can get the water out when they need it.

Getting more water absorbed into the soil depends on creating a good soil structure, with good-sized water-stable aggregates and large-sized pores. Minimizing heavy tillage (think compaction) will help towards this goal, as will increasing the organic matter, using organic mulches, including crop residues (Dale’s excellent example shows the true costs of baling corn stalks for emergency fodder and selling at $60/ton, while incurring costs of $30/ton and losing the fertilizer value of those stalks at $49/ton). After several years of this treatment, yields go down and the soil loses structure. Over-grazing leads to similar results. Bare soils cannot easily absorb water – keep roots in the ground, and preferably some foliage above ground, at all times. Animal manure on the surface also improves water infiltration – the worms and beetles that feed on the manure make burrows that allow water to reach deeper into the soil.

Dale recommends feeding hay in the fields, either unrolled or with bales spaced around the pasture. Uneaten hay and the manure add a lot of organic matter and fertility. Mycorrhizal fungi on plant roots exude glomalin, a stable gluey compound that greatly improves soil structure. The fungi themselves act like root hair extensions, increasing water uptake ability. Earthworms make burrows (air and water conduits) and line them with slime, which helps soil aggregation. Decayed plant root channels also let water deep into the soil. For best results, combine fibrous-rooted cover crops (grasses, buckwheat) with tap-rooted cover crops (brassicas, sweetclovers, sunflowers).

Sunflowers are a deep-rooting cover crop.
Photo Pam Dawling

Terracing, or other ways of working on contour help to reduce runoff and make full use of the water that does arrive. Swales, keyline shaping (contour ridges), retention dams in seasonal waterways, all aim to slow down runoff and give more opportunity for water to soak in.

The next step is to bank the water in the soil for longer. We do not want soils that rapidly evaporate all the water, leaving a brickyard. Peat bogs store lots of water, but this isn’t what we need either. How best to manage the water once it is in the soil?  Soils lose water in three ways: it gets sucked up by plants, it evaporates from the soil surface, or it leaches down below the root-zone.

Not every drop of water sucked up by plants is helping us – manage or eliminate weeds to leave more for the crops. Preventing a pound of smartweed growth can save 678 pounds of water! Better to grow a pound of crop plants. Overcrowded plants grow taller, but not stronger, as the roots are restricted. Get weeds early, we all know that. If you’ve forgotten why, this book will remind you of the science! In pasture, many weeds are crops, as far as the livestock is concerned. Sometimes rotating different types of livestock will make best use of the plants you have.

As the amount of CO2 increases, plants become more water-efficient. This is because they don’t open their stomata so wide to get enough CO2, and less water transpires out. Increase the CO2 held in the plant canopy by reducing tillage (which instantly flushes out lots). Organic no-till systems allow natural decay and slow release. Keep lots of organic matter on the surface, and if your soil is acidic, add lime.

To reduce evaporation, provide shelterbelts and windbreaks, which cut the wind speed. Research has shown that woody windbreaks increase yields from an area ten times their height. And yet, when times get hard, some farmers pay good money (that will never come back) bulldozing hedgerows to gain a tiny amount of land, with no understanding of the coming decline in yield. Protecting the soil from excessive sun can also reduce evaporation (minimize bare soil). The book has a convincing photo comparing tall healthy corn planted into hairy vetch mulch, with a shorter, curled leaf droughty corn on bare soil.

Dale explains the Law of the Most Limiting Factor, which is helpful to overwhelmed farmers seeing lots of problems. Tackle the factor that is the first to limit the growth of the crop, whether that is sunlight, nitrogen, water or something else.

Organic matter in the soil improves water-holding capacity (both the depth of water penetration and the amount per inch). Increasing soil organic matter comes up next. Anyone over 50 might have been taught that it is not really possible to increase soil OM at a reasonable price. This is not true! By good soil husbandry you can indeed improve soil OM. Conserve crop residues, add cover crops, add manure or compost, reduce tillage and observe the C:N ratio needed for humus production (1 part N: 10 parts C) and don’t forget the sulfur. Some studies seem to show that feeding the crop residues to livestock, letting the manure stay on the fields can increase yields even though the measurable %OM is not higher than if the residues had been left on the field.

The focus then moves on to helping plants get more of the water out of the soil. Improving root depth is key, but sub-soiling is not usually a good way to do this, although Dale concedes that in the Southeast, it can work for one year at a time, perhaps replacing the heavy frost heaving that happens in winter further north. If possible, find other ways to reduce compaction. The more water there is in the pore space, the less oxygen there is. Field tile drainage can help remove excess water, and prevent a low level of oxygen limiting root growth. Earthworms, deep-rooted plants, increased OM, improved aggregation all help increase oxygen flow to the roots. Increase root water-efficiency by ensuring adequate fertility; enlist mycorrhizal fungi by using an inoculant if needed.

I’m considering photocopying the chapter summary pages for a Cheat Sheet on those Practical Strategies. As I said, I skimmed the livestock farming details, but the information on the impact of drought on livestock farmers and ranchers gave me compassion for those faced with suffering animals. Having to make decisions in a hurry to prevent undue suffering can lead to long term problems for the farm. Sometimes row crops must be sacrificed to provide fodder, when pastures become “crispy brown exercise lots”. Dale has the experience. He tells of neighboring farmers getting together to net all the fish from all their ponds before the ponds dried up. They had a neighborhood fish fry, and he ate fried snapping turtle that day.

There are several reasons to keep livestock out of ponds – one is danger from ice.
Photo Ezra Freeman

Providing surface water includes keeping well-maintained ponds that livestock do not trample down. Dale shows how to provide a livestock “beach” with geotextile and gravel, and old tires forming a fence in the water. He shows how to set up a siphon to bring water out of a pond; how to set a living willow hedge to protect steam banks and pond edges; how to build a shade roof for cattle that catches and provides rainwater; how to build temporary ponds with rubber sheeting and hay bales or earthbags; how to drill a shallow well; and how to enclose a spring to protect it from trampling and provide clean water. Here’s info on addressing water quality issues such as excess nitrates, blue-green algae, salt, and sulfates; and on the use of fish trap gates to encourage livestock to move themselves to the next paddock when they need water.

The next chapter is on creating drought-tolerant pastures. Test the soil, and choose pasture plant species carefully. Here is a good explanation of the three photosynthesis pathways, discovered so far. C3 plants have 3 carbon atoms in the first product of photosynthesis. Cool-season grasses and almost all shrubs, trees and broadleaf plants (think brassicas and legumes) are in this group, which has the poorest water-efficiency, and on hot sunny days can use only about 50% of the available sunlight. The book explains why. While the plants have plenty of water, they can use it to cool the leaves; but if it’s hot and the soil is dry, growth is restricted.

C4 plants include warm-weather grasses (including corn), pigweeds, and lambsquarters. They grow best in hot weather, and are unproductive in cold weather. While they are more water-efficient, they are less digestible and low in protein. It is wise to interseed C3 and C4 grasses, adding appropriate mycorrhizal fungi for the C4 grasses, to speed up establishment and provide better long-term productivity. Add deep-rooting plants (chicory or alfalfa).

The third photosynthetic pathway mentioned is the Crassulacean Acid Metabolism (CAM) pathway, and it has by far the best drought tolerance. This pathway is found in succulents such as yuccas, cacti, pineapples. They close their stomata during the day, having stored CO2 for photosynthesis. These otherwise promising-sounding plants grow very slowly. They may have a place as drought rations, once the spines have been burned off, or the whole plants have been ground to a “soup”.

Calculating and maintaining a sustainable stocking rate will prevent the downward spiral that comes from overgrazing. Stock conservatively such that only 40% of the foliage is removed in the worst years. There are no financial savings from overgrazing. Removal of more than 40% of the leaf area results in a loss of root growth, hindering recovery. You make more money from conservative grazing than from exploitative grazing. The book has the research to prove it. Consult your local NRCS, who can calculate a suitable stocking rate (free of charge). In wet winters, it is often better to make a woodchip mulched winter feeding lot with spaced hay bales, than let the soil get “pugged”.

There is technical information here about growth stages of different grasses – it’s most important to avoid too much defoliation of cool-season grasses in late spring; warm-season grasses benefit from a rest in late summer. Plants with growing points near the ground can survive close grazing better than those with elevated growing points.

Author Dale Strickler.
Photo courtesy of Storey Publishers

Chapter 7 delves into providing emergency forage in a drought, as an alternative to reducing stocking levels and thus reducing income (hard for any farmer to do). Hopefully, using the previous info, your pastures will be improved and more drought-resilient, and you are less likely to face this emergency. If you do, the first place to look is failed rowcrops, which you can graze or cut and haul (grazing is better). Beware the urge to make silage, as it loses 20% of the feed value in fermentation. And it’s heavy to haul. Also, it leaves your fields denuded, unless you immediately sow a cover crop, which is tricky in a drought. Strip grazing using electric fencing is a better way to go, and also lets you force a better balanced diet of grain and stalks on your livestock, reducing the risks of acidosis, excess nitrates or prussic acid poisoning from young sorghum growth.

Another source of emergency rations is crop residues, such as corn stalks, strip grazed as for failed crops. It is important to understand the nutritional limitations of what you are feeding. There are feed additives used by some ranchers to increase the digestibility of some feedstocks.

Winter cover crops are another emergency feedstock in desperate winters. Tree branches, or felled trees, can save the season occasionally (obviously not every year). Plan ahead and cut poles of cottonwood or willow (whichever grows locally) and plant your own emergency feedlot. It can serve as shade and shelter in non-drought years until needed. Possibly thinning the trees the first time round could actually improve the health of the spared trees.

Another approach is to cut hay on areas that would otherwise get mowed, such as roadsides or parks or serve wetland plants, weeds, lawn clippings, dormant grasses (those bison weren’t wrong!). If you can supplement the protein with legume hay or oilseed meals, do that. For low protein feeds such as dormant grasses, choose mature, non-lactating animals. Planning ahead, it makes sense to shift the birthing season to the beginning of the high-quality grazing season.

There are various (sometimes painful) livestock decisions to make during droughts and in the aftermath. Dale recommends making a written plan, which will save revisiting the decisions each day, and will reduce the stress of making decisions in the thick of it. Deciding to reduce the herd size is easier if you have some animals that you find easier to let go of. Having such “stocker animals” that you intend to sell at some point reduces the decision to when to sell. Having some pre-set trigger dates when decisions need to be made will help you ease into it. Set an initial date to decide the stocking rate for the season, and another when half the growth of the grass will have occurred, for both your cool season and your warm season pastures.

Another strategy is to have some of your livestock be able to survive in buildings or dirt yards for a while. Far from ideal, but in a drought, we are already far from ideal, and climate chaos is going to throw us into situations we have never seen before. Make a priority list of which animals must be first to go when a reduction is needed.

When you’ve done all the things mentioned, and you still have animals to feed, look thoughtfully at hay, silage and grain. It is better to start feeding some hay while the pastures are still in good shape than to overgraze and then have only hay. You want your pasture to respond quickly as soon as rains do arrive, to regrow and be stored for winter. Have a sacrifice lot or pen, where you feed hay, and keep the animals off the pasture, so it can recover sooner. Or graze for a few hours, then feed hay in the lot.

Whatever else you do, keep notes of your observations, your actions, the results and anything you think would have been better. This will position you for better results next time.

The last part of the book looks to the future. The cautionary tale of how the Dust Bowl was created by poor farming practices is relevant to all of us. The lessons are: Farm to suit the land, the climate and the plant species already growing; don’t believe theories (“Rain follows the plow”, “Use dust mulch”, “Deeply tilled soils will catch more rain”) disseminated by people living far away, or companies that are set to gain from farmers following their advice; don’t move hundreds of miles and expect to farm the same way you did “back home”; check the research for results you can depend on, think it through for yourself, and watch what is working for farmers around you, before trying something really different.

Reading about how the Plains are suited to grazing is instructional for anyone who thinks animals should be eliminated from agriculture. Living in central Virginia, I am not in a place to make an informed judgement, but Dale Strickler is. He has a system of capturing falling rain in grasses or cover crops, converting 40% into meat or milk (by grazing, which adds manure to the soil) and leaving 60% to cover the soil. In drought years, maintaining a flexible mind, using those decision-point dates to make best choices for the current year, having some “flex-pastures”, considering all your options rather than panicking, are going to help.

Also see this article picked up by ATTRA on research using sheep to graze cover crops and vegetable crops

 

Sweet corn, potatoes and okra

Our first sweet corn of the season (Bodacious).
Photo Pam Dawling

Sweet Corn

We sowed our first sweet corn on 4/18, eight days earlier than usual this year, because we had auspicious weather. We look at the leaves of the white oaks to decide when it is warm enough for corn planting. The oak leaves should be as big as squirrel’s ears. Phenology signs like this are especially useful when the weather is extremely variable, which we are getting more of as climate disruption has got us in its grip.

Our first sweet corn sowing is always a bit of a risk. In fact we often prepare for this by sowing some corn seeds in styrofoam Speedling flats, the same day we sow the first corn planting outdoors. Read more about this seedling technique and transplanting corn.

Our third planting of sweet corn on the left, fourth in the middle, 5th (barely emerging) on the right.
Photo Pam Dawling

We’ve been harvesting sweet corn since July 2, which is two days earlier than our target start date, so we’re very happy. Initially, of course, we got smaller amounts, but we are now harvesting three times a week and getting good amounts. We are back up to 6 sowings this year, after we had to cut back for a couple of years. For a hundred people we sow an average of 1100 ft (335m) each time we plant, with each planting intended to last us 15 days (7 or 8 pickings). Our goal is sweet corn from July 4 to mid-October (our average first frost is October 20, a 13 year average from our own records).

Three varieties of sweet corn in one planting. On the left Bodacious; in the middle, red-flowered Kandy Korn; on the right, Silver Queen not yet fully grown.
Photo Kathryn Simmons

Each sowing includes several varieties (with different numbers of days to maturity) on the same day, so a planting will give us at least two weeks of delicious corn. In this photo from a previous year, you can see (from left to right): later-maturing Silver Queen, not yet at full height; red-flowered Kandy Korn; fast-maturing shorter Bodacious. Each plant is only going to provide two or three ears, so to have enough, and to have a continuous supply, it is necessary to plan ahead. See the Succession Planting section ahead.

Sowing sweet corn

We have switched to sowing corn with the EarthWay seeder, with a homemade next-row marker. This is much quicker than sowing by hand, but does rely on providing overhead irrigation consistently until the seedlings emerge. Another trade-off is that we get more weeds germinating in the (watered) aisles than we did when we only watered the furrows at planting time. Drip irrigation would be another approach.  So far we have not lost corn to crows, which was the reason we took to the handsowing-under-ropes method some 20 years ago. Back then we also sowed our fist corn with a tractor seeder, but we had to follow that with putting up ropes, or we lost it all to birds. Details of our hand-sowing method are in this post from May 2016.

Staying on top of weeds in the sweet corn

Once we get to late June, more of our time in the garden is taken up by harvesting (a sign of success), leaving less time for weeding. We have a system I like that helps us stay on top of sweet corn weeds. Each time we sow sweet corn, we hoe the previous planting (about two weeks old), thin the plants to one every 8″-12″ (20-30cm) in the row, and wheel hoe or till between the rows. We have two Valley Oak wheel hoes that we really like. The handle height is adjustable and they are available with different width hoes (and other attachments). Our tiller is a BCS 732 from Earth Tools BCS

Don’t let this happen to you! Weedy young corn.
Photo by Bridget Aleshire

We also hoe the rows of the corn planting before that one (about 4 weeks old), and till between those rows and broadcast soybeans (which we till in lightly). Soybeans will grow in partial shade, handle the foot traffic of harvesting, and provide some nitrogen for the soil. For the last corn of the season, we undersow with a mix of soy and oats. After the harvest ends, we leave the patch alone, and the oats survive the first frosts (which kill the corn and the soy) and go on to be our winter cover crop for that plot. When it gets cold enough, the oats do die, and the plot becomes an easy one to bush hog and disk in the early spring for our March-planted potato crop. I like that opportunity to eliminate one round of disking, and to get a winter-killed cover crop established

As we harvest corn we pull out any pigweed that has somehow survived our earlier efforts. I learned at a Sustainable Weed Management workshop, that pigweed puts out its seeds in one big bang at the end, so pulling up huge pigweed is worthwhile, if it hasn’t yet seeded. (Actually you can see it for yourself, but before the workshop I hadn’t noticed!) Our soil has improved over the years, so it is now possible to uproot 5ft (1.5 m) pigweeds. Sometimes we have to hold the corn plant down with our feet, but we do almost always succeed in getting the weeds out, without damaging the corn.

Succession Planting for Sweet Corn

In Sustainable Market Farming I have a chapter on succession planting, and my slideshow on Succession Planting is one of my most popular ones. You can watch it right here.

I posted on Mother Earth News Organic Gardening blog about Growing Sweet Corn for the Whole Summer. You can read it here:

Growing Sweet Corn for the Whole Summer – Organic Gardening

Our sweet corn sowing dates and harvests from those plantings are

  1. 4/26, harvest 7/9 (with a few ears from 7/4)
  2. 5/19, harvest 7/24
  3. 6/6, harvest 8/8
  4. 6/24, harvest 8/23
  5. 7/7, harvest 9/7
  6. 7/16, harvest 9/22

Avoid mixing types of corn.

There’s a confusing aspect of hybrid corn varieties: There are several genotypes, and if you inadvertently plant a mixture of different types, it can lead to starchy unpleasant-flavored corn. Also don’t plant Indian corn, popcorn or any kind of flint or dent corn within 600′ (180 m) of your sweet corn. For this reason we grow only sweet corn in our garden. Ignore those cryptic catalog notes at your peril!

Dealing with raccoons, skunks and curious cats in the corn

We have trapped (and then killed) raccoons in our corn most years, and the past few years we’ve tried deterring them with nightly radio broadcasts. We have the large live mammal traps, and we found for raccoons, we needed to stake the trap down to the ground. I followed suggestions from Joanna Reuter of Chert Hollow Farm, staking the traps down and smearing peanut butter high on the stake in the back of the cage. Well, the first morning I caught a small, very white skunk! I let it out carefully. The next morning I caught the same skunk again. And the third morning, again. You can read more about how I let the skunks out. I’ve also caught some of our cats by accident.

Raccoons don’t seem to like Silver Queen as much as Kandy Korn, maybe because the husks are tighter and harder to rip off. Actually I like Kandy Korn better than Silver Queen too.

Okra

Cow Horn okra flower and pod.
Photo Pam Dawling

We have started harvesting our okra. It’s 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 planted it out 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. This is why I think the problem is that we over watered rather than under-watered.

This year we are trying Carmine Splendor, a red okra from Johnny’s, as well as our usual favorite Cow Horn from Southern Exposure.

Cow Horn okra pods.
Photo Bridget Aleshire

We like Cow Horn for its tall plants, high productivity and the fact that the pods can get relatively large without getting fibrous. They are still tender at 5-6″, which is the size we used to harvest at. Some years we have attached a card to the handles of the pruners we use for this job, with a life-size drawing of a 5″ pod. This helps new crew get it right.

We do find it very hard to convince our cooks that we have specially chosen this “commune-friendly” variety so they don’t have to deal with fiddly little okra pods when cooking for 100. We’ve had to compromise and harvest at 4″. Hence the venturing-out to another variety, accepting people are hard to convince about Cow Horn!

We grow a 90′ row, with plants about 18″ apart in the row. This is enough for the hundred of us (some people never eat okra despite the cooks’ best efforts!)

Carmine Splendot okra plant.
Photo Pam Dawling

Carmine Splendor is a 51 day (from transplanting) F1 hybrid, with sturdy 5-sided pods that are deep red when small. I haven’t tasted them yet.

Potatoes

June-planted potatoes emerging from mulch in mid-July.
photo Pam Dawling

Our June-planted potatoes are starting to come up through the hay mulch, and we need to walk through and free the trapped shoots. This means we walk through investigating the spots where we expect there to be a potato plant but we don’t see one. If we find a trapped shoot, we open up the mulch to let the plant see the light. We do this same job with garlic in late November or early December.

This week we are harvesting our March planted potatoes. I just dug 30lbs for tonight’s dinner. Yes, lots of diners! The rest of the crop will be harvested using a digging machine on Thursday.

We harvested our March-planted potatoes 21 days ago, and we are in the process of sorting them and managing conditions in our root cellar to cure the potatoes and help them store well.

Crates of potatoes in our root cellar.
Photo Nina Gentle
Click here for our Root Cellar Warden” instructions from last year.

Dormancy Requirements of Potatoes

We are researching the dormancy requirements of potatoes in an effort to store ours so they don’t sprout when we don’t want them to!

What I know so far about dormancy is that potatoes need a dormancy period of 4-8 weeks after harvest before they will sprout. So if you plan to dig up an early crop and immediately replant some of the potatoes for a later crop, take this into account. Get around this problem by refrigerating them for 16 days, then chitting them in the light for 2 weeks. The company of apples, bananas or onions will help them sprout by emitting ethylene.

To avoid sprouting, keep the potatoes below 50F (10C) once they are more than a month from harvest, avoid excess moisture, and avoid “physiological aging” of the potatoes, caused by stressing them with fluctuating temperatures, among other things.

Tobacco Hornworm pupa

Just had to add this, which I dug up yesterday. These brutes are about 2″ (5 cm) long. They are heavy and they move slightly. Also, check out the comments on the last post and be sure to see SESE’s Ken Bezilla’s Instagram of a hornworm in black light.

This is the pupa of the tobacco hornworm.
Photo Pam Dawling

Dealing with Hornworms on Tomatoes

 

A large tobacco hornworm. Note the fake eyes near the horn at the tail end.
Photo Pam Dawling

Two summers ago, I wrote about Hunting Hornworms on Tomato Plants.

Here we are in July again, and here are the hornworms again! Yesterday, in two 80 ft (24.4 m) rows of tomatoes, I found 53 inches (1.35m) of hornworms! There were 24, varying in length from 1” (2.5 cm) to 4” (10 cm). Today I found even more: 42 caterpillars totaling 85” (2.2m)! They are stripping leaves and munching on the green fruit.

In our hornworm photos, you might notice ours are not the same as yours. Ours are tobacco hornworms, not tomato hornworms, but both are bad news and both attack tomato plants. Before Twin Oaks Community started here in 1967, the land was a tobacco farm. Tobacco hornworms have a red (not black) horn, and diagonal white lines, not arrowhead vees.

Hawk moth (mother of hornworms) caught in a web of a zipper spider. Photo Pam Dawling

Hornworms hatch from eggs laid by the night-flying Carolina sphinx moth or  Tobacco hawk moth. This year I did catch one of the moths, and kill it, but we still have plenty of caterpillars. The moths hatch from strange coppery pupae with pipes or spouts attached, which overwinter in the soil. Even our most vigilant caterpillar-hunting seems to miss some, which then drop to the ground to pupate. Another way to break the lifecycle is to close the hoophouse at dusk every night (and open it promptly every morning before it gets too hot), but we’ve decided not to go that route.

Hornworm with parasitic wasp pupae.
Photo Pam Dawling

Hornworms often get parasitized outdoors by a tiny braconid wasp that lays eggs in the backs of the caterpillars. The larvae develop inside the caterpillar and then the pupae develop as white rice-grain-like cocoons sticking out of the back of the hornworm. Usually our friend the parasitic wasp doesn’t come inside the hoophouse and to get parasites into the hoophouse hornworms we have to bring in parasitized hornworms from outdoors. This doesn’t work so well, because the hoophouse tomatoes are a month earlier than the outdoor ones, and the hornworm cycle is well underway in the hoophouse by the time the parasitic wasps are in action outdoors. This year we’ve found several parasitized hornworms indoors in the past few days, and we are very happy.

Hornworms have stripped these tomato leaves.
Photo Pam Dawling

Meanwhile, we are conducting hunting raids every morning. To find where the hornworms are working, first look at the upper leaves of the tomatoes. If they are stripped bare down to the ribs, that’s a good place to look. Hornworms only like the tender upper leaves. If there are intact newer younger leaves, it might mean there was a hornworm, but it’s been removed already, and the plant is recovering. Another sign of hornworms in the area is chewed fruit. Another sign is “pineapple poop” – miniature brown pineapples or hand grenades. If you see fresh poop, look directly upwards – remember the law of gravity. The size of the poop is, naturally enough, in proportion to the size of the hornworm.

Hornworm poop on a tomato.
Photo Pam Dawling
Evidence of hornworms.
Photo Pam Dawling

Having determined there is a hornworm in the vicinity, the next task is to find it. You’d think it would be easy – a big striped caterpillar like that. Not so! They are the exact same shade of green as tomato leaves. Hornworms can look remarkably similar to curled tomato leaves. The white stripes mimic the veins on the undersides of the leaves.

When I find some signs, I gaze at the area, looking for discrepancies in the pattern – bare stems with lumps on them. Usually the caterpillar is on the underside of a chewed stem, and often (but not always) they have their heads raised. When you find one, get a firm grip, pull it off the plant (they have strong legs which hold on tight), drop it on the ground and stomp on it. The skins are quite thick.

Found it! Hornworm on a tomato leaf.
Photo Pam Dawling

If I still can’t see the worm, I stand still and sway a bit from side to side, viewing the plant from different perspectives. It helps if the top of the plant is back-lit, but I do always check both sides of the row, no matter where the sun is. Knowing the signs of hornworm grazing can save you time looking everywhere. Focus your attention on where you are most likely to find them, and you will get the most success in the least time.

A large hornworm eating a tomato.
Photo Pam Dawling

Bt is an organically-approved pesticide spray that kills small caterpillars, without killing other insects. I don’t expect it to work on big hornworms. Hunting seems to be the way to go!

Our goal – tasty ripe tomatoes! These are Five Star Grape.
Photo Pam Dawling

Cooking Greens in July

 

Early spring cabbage with alyssum to attract beneficial insects.
Photo Pam Dawling

Here in central Virginia in July, we have chard and spring cabbage for cooking greens, the last broccoli, and some collards early in the month.

Sowing the fall greens is well underway. We also start transplanting cooking greens this month – it’s very hot, but this is when we need to do it, to have the crops mature before it gets too cold for them.

Cooking Greens to Harvest in Central Virginia in July

See June’s Cooking Greens post for more about chard, a biennial that will not bolt in the summer heat. We can eat it whenever we like; it is always there, always harvestable, from late May to late December. It’s so easy to care for, and nothing bad happens if we ignore it. Some years it even survives our winters.

Our broccoli comes to an end in early July, when it gets bitter, and has only tiny side-shoots left. We are harvesting our cabbage. We sowed early cabbage in our greenhouse in late January and transplanted it around March 10. We sowed our main-crop cabbage February 7 and transplanted around April 1. In our early cabbage, we grew Farao (F1, 60d, 3lbs, 1.5 kg), Early Jersey Wakefield, (OP, 63d, 2-3lbs, -1.5 kg)), and flat, mid-sized, Tendersweet (F1 71d). For the maincrop, we have more Farao and Early Jersey Wakefield, along with Red Express, Kaitlin and Tribute.

A cabbage, with curled back leaf on the head, showing maturity.
Photo Bridget Aleshire

We store cabbage beyond our immediate needs in net bags in the refrigerator. None of these spring varieties are long-storers, but they should see us through the summer until mid-October when we have fresh outdoor fall cooking greens. We eat a 50lb (23k) bag of cabbage each week, so we aim to get 12 bags into storage, by the time the harvest ends in mid-July. Additional cabbage beyond the 12 bags (if any) gets made into sauerkraut. Our main sauerkraut making season is when we harvest the fall cabbage, which is usually a bigger planting.

That’s it for cooking greens harvests here until late August, when our fall planting of Senposai will start to yield. Some years we have sowed Tokyo Bekana or Maruba Santoh for a quick harvest. Both are very fast growing tender chartreuse (yellow-green) leafy plants that can be served chopped and lightly cooked. Tokyo Bekana a Brassica rapa chinensis type and takes 45 days to full maturity. Maruba Santoh, Brassica rapa pekinensis, is similar to Tokyo Bekana but less frilly. Fairly bolt tolerant. Only 35 days to maturity.

We have sometimes planted these for salad leaves to get us through late summer lettuce shortages. The wide white stems of the mature plant provide crunch for salads, along with the delicate leaves; or the baby leaves can be harvested. Both have a mild flavor and even so, I have been surprised that many people don’t even notice they are not eating lettuce – I suppose enough salad dressing masks all flavors!

An adolescent Tokyo bekana plant.
Photo Pam Dawling

Cooking Greens to Sow in Central Virginia in July

In May, I described our planning for our fall brassica nursery seedbeds. In June I described our schedule of weekly sowings, hooping, netting, watering and weeding. Weeks 3-6 fall in July, so now I’ll tell you about those. Weeks 7 and 8 are in August.

We sow the fall brassicas weekly throughout July – see the Special Topic for June for all the details. Each week we resow anything from the previous week that did not germinate well or became casualties. We sow these top-ups for any varieties with germination less than 80%, in a fresh row, with a new label, to avoid confusion.

In week 3 of our Fall Brassica Transplanting Schedule, (the first week of July) we sow broccoli and cabbage for the second time (insurance!), and senposai, Yukina Savoy and Chinese cabbage (if we are growing it that year) for the first time.

In week 4, (the second week of July) we sow the Chinese cabbage, senposai and Yukina Savoy for the second time, and collards for the first time. If we have to resow broccoli or cabbage, we choose the faster-maturing varieties.

In week 5 (the third week of July) we sow collards for the second time. Week 6 has no new sowings, only resows for anything that didn’t come up well..

It’s also possible in warmer areas to sow Swiss chard or leaf beet for a fall crop. This might be a useful Plan B if some other crops have failed. The last planting date is ten weeks before frost. The winter-kill temperature is 15°F (–10°C) for multi-colored chard, 12°F (-11°C) for red chard and 10°F (-12°C) for green chard (Fordhook Giant). Asian greens can also be direct-sown this month. We prefer transplants for several reasons: it’s easier to protect close-packed seedlings from pests than whole beds; it gives us extra time to grow a round of buckwheat as cover crop in the beds, and improve the organic matter and reduce weeds.

A netted bed of brassica seedlings on July 4.
Photo Pam Dawling

Cooking Greens to Transplant in Central Virginia in July

Now is the time to prepare our plot for the fall broccoli and cabbage transplanting as I described in June, mark out the rows and start transplanting.

We aim to transplant most brassicas at 4 true leaves (3-4 weeks after sowing in summer), but it often slips to 5 weeks before we get finished. I recommend transplanting 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. It would make an interesting experiment to see which actually does best: 3 week transplants, 4 week transplants, or 5 week transplants with 2 leaves removed. Possibly the larger root mass of the older plants would be an advantage. On the other hand, old, large transplants can head prematurely, giving small heads. By that point in the year, my scientific curiosity has been fried by the sheer workload of crop production!

Week 4 (the second week of July): Transplant week 1 cabbage (especially the slower-growing “late” varieties). Cover: hoop and net or rowcover.

Week 5 (the third week of July): Transplant Chinese cabbage, Tokyo Bekana, Maruba Santoh sown in week 3. Yes they really will be big enough at 2 week-old! Transplant week 2 sowings of cabbage, broccoli, cauliflower, and any week 2 resows. Cover: hoop and net or rowcover.

Week 6 (the fourth week of July): Transplant week 3 sowings of cabbage, broccoli, cauliflower, senposai, Yukina Savoy, collards; week 4 Chinese cabbage, Tokyo Bekana, Maruba Santoh, and any week 3 resows. Cover: hoop and net or rowcover.

We plan to have transplanting crews 6 days a week for an hour and a half or two hours in late afternoon or early evening, for 2-3 weeks, not counting the kale transplanting, which happens later. We water the seedlings one day and again one hour before digging them up. We plant to the base of the first true leaves, to give the stem good support, and we firm in well, so the roots have good contact with the soil, and do not die in an air pocket. After transplanting, we water generously within half an hour of planting, and again the third day, and the seventh, and then once a week. We use overhead sprinklers, and don’t easily have the option of watering every day. If you have drip irrigation, you can more easily give a little water in the middle of each day, which will help cool the roots.

A harvest cart with cabbage, kale, squash and lettuce.
Photo by Wren Vile

Other Cooking Greens Tasks for July

No visible brassicas month! In early July, the last of our spring brassica crops get harvested, and all the seedling brassica crops are under netting. There are no brassicas for the harlequin bugs to feed on and multiply in, for at least one month. We hope this will break their lifecycle. When we transplant the young brassicas, we cover those all with netting or rowcover for a few weeks.

Special Cooking Greens Topic for July: Unusual Hot Weather Cooking Greens (More in August)

All the following are warm weather crops, so wait till the soil temperature is at least 60°F (16°C) before direct sowing. If sown after mid-June, they can follow an earlier crop such as lettuce or peas.

Leaf amaranth, Amaranthus species.

Amaranths are found across the globe. There are two basic types: seed amaranths, used as a grain, and leaf amaranths. Callaloo is another name for leaf amaranth (but sometimes other crops have this name), widely used in the Caribbean. Amaranth leaves make tender and nutritious cooked greens.

This tropical annual plant thrives in really hot weather. It is a huge plant, 4’-6’ (1.2-1.8 m) tall. Some are very attractive, looking like coleus.

Carol Deppe in The Tao of Vegetable Gardening recommends All Red for a spectacularly colorful leaf, especially for salads, and Green Calaloo and Burgundy for fast-growing greens. She reports they all taste the same to her raw, and all taste the same when cooked. So choose based on your preferred color and rate of growth.

Joseph’s Coat, Amaranthus tricolor, is an eye-catching plant with red, green, and yellow leaves that may also include patches of pink, bronze, purple and brown.

William Woys Weaver (Heirloom Warm Weather Salad Greens, Mother Earth News) is a fan of ‘Bliton’ or ‘Horsetooth Amaranth’, Amaranthus lividus (Amaranthus viridis). He reports that it is the easiest and most prolific of summer greens.

In colder regions, start seed indoors, and transplant when it’s warm enough to plant beans or corn (Frequent advice for many of these hot weather greens). In warmer regions, direct sow in rows after all danger of frost is past, or broadcast with the aim of getting plants 4” (10 cm) apart. Succession-sowing in summer to provide continuous harvests.

Thin the seedlings to at least 6” (15 cm) apart (use for salads) and each time the plants reach 8-12” (20 -30 cm), harvest the top 8” (20 cm) for cooking. This pinching back will encourage bushier plants with new leaves and prevent reseeding. If grown for a single harvest, pull plants about 12” (30 cm) tall.

The crop is ready 50 days after sowing. It is tasty steamed or stir-fried like spinach. The tender leaves have a sweet nutty flavor.

When the plant is older, the stems get too tough, and then only the leaves and new shoots should be used. Some people say that amaranth should not be eaten raw, but I have failed to discover why, and others recommend it as salad.

In parts of the South, it has become a weed – “Grow responsibly,” as Barbara Pleasant says in her Mother Earth News blogpost Warm Weather Spinach Alternatives. If your farm has lots of amaranth weeds, you won’t want to risk adding another.

Red-root pigweed is an amaranth. If you have this weed and its striped flea-beetle, you will also find your edible crop full of holes and not saleable. For this reason, we don’t grow amaranth crops.

Aztec Spinach, Huauzontle, (Chenopodium berlandieri).

The chenopods (goosefoot family) are now considered a subfamily of the Amaranth family, which is related to true spinach. This plant has bigger leaves, more tender stems and better resistance to bolting than common lambsquarters, which is also edible.

Broadcast and thin to 4” apart, harvesting young leaves for salad just 30 days after sowing. When 12” tall, harvest the top 8”. This could be less than 8 weeks from sowing, depending on your climate. After the first harvest, thin the plants to 12”-15” (30-38 cm) apart, and the bushy new growth will provide leaves for future harvests. Each plant can produce a pound (0.5 kg) of colorful leaves, which steam in just one minute, and keep their color when cooked. Later, the plants with flowerbuds are cooked for breakfast. Wrap the stems with buds around a soft white cheese, dip the whole thing in batter and then fry the fritters, and simmer in a chili sauce. This may be more a springtime dish than a summer one, depending when the plants start to flower.

Hot weather increases productivity, while cooler fall weather increases the color intensity of the leaves. Succession-sowing in summer may be the solution to providing a later crop.

There is also a red version – the lower leaves turn bright red as they mature, and stay red when cooked. An attractive red and green plant, this crop can make a dramatic statement in the vegetable garden. Aztecs grew it between rows of corn. It can grow to 8’-12’ (2.4-3.7 m) tall, although it is a skinny plant, not bulky.

Magenta Magic orach.
Photo Southern Exposure Seed Exchange

Orach (Atriplex hortensis) is another member of the Chenopod family, and comes in several attractive green, red and purple color schemes. It is also salt-tolerant. It can be tricky to transplant, needing plenty of water. The plants produce small leaves, and set seed liberally, although it is not usually invasive. Thin to 6” (15 cm) apart. Orach has a star role as elegant baby salad leaves, but it can also be grown to full size and eaten steamed. The flavor is good, and the color is retained after cooking.

Good King Henry, Chenopodium bonus-henricus, aka Mercury or Lincolnshire Spinach, has thick long-stemmed, arrow-shaped leaves. It is rich in vitamins A & C, and calcium This hardy perennial is a fairly untamed plant that bolts easily, vigorously self-seeding. So don’t expect a long picking season. Early in the year the emerging shoots may be picked and eaten like asparagus.

Magenta Lamb’s Quarters, Chenopodium album, has beautiful colorful leaves.  It has a mild flavor raw or cooked. This is basically a giant weed, which grows to 6’ (1.8 m) and re-seeds readily, so keep it from seeding if you don’t want an invasion.

Strawberry Spinach/Beetberry Greens, Chenopodium capitatum is an ancient plant from Europe. It is similar to lambsquarters in habit, but only 18” (45 cm) tall. The triangular, toothed leaves are thinner than spinach, very nutritious, and high in vitamins. This plant is also grown for the small, mildly sweet, strawberry-like fruits at each leaf axil. It can re-seed vigorously and become invasive.

Edible Celosia, Celosia argentea comes from tropical Africa, where the fresh young leaves are used in a dish of various vegetable greens, combined with onion, hot peppers, eggplant, vegetable oil, and fish or meat. Peanut butter may be added as a thickener. The ingredients are boiled together into a tasty and nutritious soup. Ira Wallace at Southern Exposure Seed Exchange reports that in their trial in Virginia it didn’t suffer from a single pest attack.

Next month I’ll tell you about some more hot weather greens.

Hoophouse Squash Variety Trial, Garlic Recap, Flowers for Organic IPM

Golden Glory Squash in our hoophouse in mid-June.
Photo Pam Dawling

Hoophouse Squash Variety Trial

A month ago I wrote about our hoophouse squash variety trials for pollination issues and blossom end rot. I think our problem was mostly unpollinated squash, rather than blossom end rot. Go to last month’s post for valuable links to distinguish the two conditions.

We planted 15 Golden Glory zucchini (good at setting fruit without pollinators) along with 25 Gentry yellow squash (a favorite variety, except that we had pollination troubles with it in our hoophouse for several years). The trial is almost over, we’re about to pull those plants, and we have plenty of squash coming in from our outdoor plantings now. The first outdoor planting includes some Golden Glory too, so if I have more news I write about it when it happens.

Gentry yellow squash in our hoophouse in mid-June
photo Pam Dawling

As I said last time, I recorded the number of small rotting squash we removed. The Golden Glory produced far fewer rotten unpollinated fruit.

Date 15 Golden Glory plants: rotted fruit Golden Glory: rotted fruit per plant 25 Gentry plants:

rotted fruit

Gentry:

rotted fruit per plant

5/13 2 0.13 12 0.48
5/14 2 0.13 5 0.2
5/17 0 0 32 1.28
5/21 15 1 54 2.16
5/27 9 0.6 39 1.56
6/4 13 0.9 29 1.2
6/10 2 0.13 11 0.46
6/14 2 0.13 9 0.43
Average per plant   0.38   0.97

 But low numbers of rotted fruits is not the only goal! Yield is important too, and the healthiness of the plants (which relates to yield).

We noticed that the plants were starting to die, and we thought of bacterial wilt. But when I tried the test for that disease, the results were negative. The test is to cut through the plant stem, rub the cut ends together, then slowly separate them. If the plant has bacterial wilt, there will be bacterial slime in strings between the stem ends when you slowly draw them apart. We got nothing like that. More research needed!

We pulled the dying squash, put them in a black trash bag and set that in the sun to cook.

Diseased squash, mid-June.
Photo Pam Dawling

Here’s what we found:

Date 15 Golden Glory plants: Number of healthy plants Golden Glory: Percentage of plants healthy 25 Gentry plants:

Number of healthy plants

Gentry:

Percentage of plants healthy

6/4 15 100% 25 100%
6/10 15 100% 24 96%
6/14 15 100% 21 84%
6/18 10 67% 20 80%
6/24 6 40% 18 72%

Initially, the Gentry started to keel over, then suddenly the Golden Glorys weren’t so glorious!

As far as yield, we did not measure it much. We only have notes from one day, 6/10. We harvested 7 squash from 15 Golden Glory plants (47%) and 14 Gentry from 24 plants (60%). Different people harvested on different days, meaning sometimes they were picked bigger than on other days. My sense is that the Golden Glory were not as productive throughout their harvest period. They are beautiful, the plants are open, easier to harvest from, and we had fewer rotten squash, and initially fewer dying plants. Is this enough to recommend them for an early hoophouse crop in future years?

My inclination is to also try another variety that is rated well for setting fruit without pollinators (hence fewer tiny rotting squash) and try harder to also record yield as well as problems next year!

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Garlic Recap

Our garlic is at the “Trim and Sort” stage, but depending where you garden, yours may be at a completely different stage. See my blogposts from the previous year, when I posted my Alliums for the Month Series.

Trimming garlic stems.
Photo by Brittany Lewis

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For people in colder climates than Virginia, you may be just starting to harvest your garlic. Learn from Margaret Roach (who grows in Massachusetts) in A Way to Garden

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Here are a couple of allium resources that didn’t make it into the Alliums for the Month Series

Mulching alliums

The Nordells on mulching alliums

RAMPS

Barry Glick sells ramps

“The Cat Is Out Of The Bag”!!!
Sunshine Farm & Gardens
696 Glicks Road
Renick WV 24966 USA

Ramps plants.
Photo Sunshine Farm and Gardens

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Flowers for Organic IPM

This is my post on the Mother Earth News Organic Gardening Blog

Organic Integrated Pest Management involves tackling pest problems one step at a time with ecologically-based practices, starting with reducing the chances of the pest ever getting a grip on your crops. Follow prevention with avoidance, and finish with pest-killing if needed. I recommend the ATTRA online publication Organic Integrated Pest Management. Each  page is a poster, complete with good photos and concise clear info.

In May we transplant flowers in our vegetable garden to attract pollinators and pest predators. We like a combination of sunflowers, dill, borage, cosmos, calendula, tithonia (Mexican sunflowers), zinnias. See my earlier Mother Earth News post Insectaries: Grow Flowers to Attract Beneficial Insects

We sow sunflowers about every 10ft (3 m) in each of our bean beds. We are growing sesame surrounded by French marigolds in our hoophouse to deter nematodes, which we have in parts of our hoophouse soil. Sesame is apparently particularly good in deterring root knot nematodes, the type we have.

French marigolds and sesame to deter Root Knot nematodes in our hoophouse.
Photo Pam Dawling

Book Review: Worm Farmer’s Handbook

 


Rhonda Sherman: The Worm Farmer’s Handbook: Mid- to Large-Scale Vermicomposting for Farms, Businesses, Municipalities, Schools and Institutions,

Chelsea Green, 2018, 247 pages, $29.95

 The Worm Farmer’s Handbook is exactly that. It explains very clearly how to farm worms on food scraps, manure, yard waste, paper and more. It goes beyond the “tub under the kitchen counter” scale of worm bin, upwards to commercial farming and community-scale enterprises. Rhonda Sherman is an excellent writer, inspiring, concise, personable, candid and very down-to-earth. Art and science. Detail without fluff. For beginners and upgraders.

The book includes the many reasons you might venture into vermiculture (worm production) or vermicomposting (worm cast production); earthworm biology; business plans; equipment set-ups; bedding and stocking rates; feeds and feeding methods; monitoring for success; harvest and post-harvest practices; and over two dozen global case studies, including some in places I bet you didn’t think of: Turkey, Afghanistan, and an air force base in Ohio. Some highly successful business people got some of their boost from worm farming.

Rhonda Sherman started as a recycling consultant, producing a much-scorned-at-the-time factsheet Worms Can Recycle Your Garbage, which became immensely popular. Answering the demand, she created the annual NC State Vermiculture Conference, the only one of its kind in the world. In 2000 she established the NC State Compost Learning Lab, with 26 kinds of composting and vermicomposting bins and space for hands-on teaching. So, she has full credentials to tell us about how to produce vermicast for profit or manage waste produced on farms and gardens, in municipalities, industries and institutions.

A tour of the Worm Barn at the NC State Compost Learning Lab

First, to clarify the terminology: vermiculture is the raising of worms for bait or animal feed or for selling to other worm farmers; vermicomposting is the conversion of organic wastes into worm castings (vermicast), a nutrient-rich, microbially active soil amendment or growth medium for young plants. The word vermicompost is sometimes used to refer to a mixture of castings, uneaten bedding and feedstock (organic material). To avoid confusion between compost (a thermophilic aerobic process) and vermicompost (a warm-not-hot mesophilic process involving the material passing through earthworms), Rhonda uses the word vermicast.

Nowadays the main reason for worm farming is to process organic wastes and use the vermicast to grow stronger, more nutrient-dense food crops or marijuana. It is possible to keep costs low, even fairly large-scale, by manufacturing your own worm bins and by screening the vermicast manually, or with a small motorized sifter. Additional income can come from selling vermicast tea and teaching classes.

Vermicast sells at a much higher price than regular compost, 7-60 times more! The microbial populations in vermicast are much larger and more diverse than those in thermophilic compost. Seeds germinate more quickly in vermicast-amended soil, the seedlings grow faster, the root mass is much bigger, leading to earlier, bigger yields. Strangely, and proven scientifically, all these improvements are independent of the nutrients available to the plants. The turnip photo is astounding. Crops with vermicast-amended soil have greater resistance to insect pests, because the vermicast adds phenolic compounds to the plants, making them distasteful to bugs (but apparently not to humans!). Plant parasitic nematodes (such as the root knot nematode Meloidogyne hapla) can also be suppressed.

Photo https://medium.com/compost-turner-fully-hydraulic-composting-machine/what-is-vermicomposting-b83428572c6c

The earthworm biology chapter is fascinating. Rhonda opens by saying “I don’t want to put you to sleep with a long-winded discussion of the anatomy and physiology of earthworms.” No danger of that. This is concise, technical and yet easy reading. Who knew there are species of earthworms that reach lengths of 3ft (91 cm), 4ft (1.2 m), 4.5ft (1.4 m), 6ft (1.8 m), 13ft (4 m) and an eye-watering 22ft (6.7 m). Only the smallest two of those are in the US, and no, not in Virginia! Some earthworms don’t live underground in the soil – the epigeic group live in the leaf litter. Seven species of worms are suitable for vermicomposting, and Eisenia fetida, the red wiggler, is by far the most widely used.

To start a worm bin, buy at least 1lb (0.5 kg) of these worms per square foot (0.09 m2) of surface area. That’s much denser than I imagined. And don’t go to the bait shop, because you’d have to buy dozens of packages for every pound of worms, throw out all the containers, and pay $122-$225. From a reputable worm grower you will pay $20-50 per pound, perhaps with added shipping.

Rhonda walks us through all the necessary steps of preparing to farm worms. Study the state and local regulations, and the safety issues, and make a business plan before buying worms, except perhaps for a small pilot scheme. Don’t expand before you know how you will make it work. Production and marketing are equally vital. Will your state regard this as a composting process (lots of regulations) or a livestock farming enterprise? Plan to avoid the problems and have contingency plans in case they happen anyway.

Photo NC State https://composting.ces.ncsu.edu/vermicomposting-2/vermicomposting-for-business-farms-institutions-municipalities/

In designing your physical set-up, there are options from small outdoor pits or bins to continuous flow-through bins. Buy or build your own, after studying the pros and cons. Look for suitable readymade containers at a good price, such as Macrobins and IBC totes used for vegetable and other storage and transport. Source your feedstocks and decide if it would be best to pre-compost them before offering to your worms – often wise if dealing with large deliveries of food waste, to reduce volume and pest problems. This book helps with information on the space you’ll need for all stages of the process. Plan ahead. Imagine yourself 10, 20 years older when delivering feedstock, monitoring your livestock and emptying your bins. Don’t build things too wide, tall or heavy. Leave access space all around your bins (unless very narrow). Imagine more climate change.

Don’t geek out too much on the equipment though – remember you are farming livestock and will need to prioritize learning their ways. You need a 6″ (15 cm) layer of moist bedding, a layer of worms at a sufficient density for the container, a thin 1-1.5″ (2.5-3.8 cm) layer of feedstock and a covering layer, so the worms can eat without being exposed to the light. Enough air and water, light to prevent them crawling away. Wait till they’ve eaten all you’ve provided before adding more food, or you will get fruit flies, gnats, flies, ants etc. Rhonda advises on various feedstocks. Check at least once a day, to make sure your worms are healthy, thriving and mot crawling out of your bin. As needed each day, water the top of the bin, using a mist or light fine spray.

Worm farming can fit with other types of farming with good results. Livestock manure (except poultry manure) is a good feedstock for worms. You can experiment with adding some worms to a composting toilet. Vegetable, fruit and flower crops can provide crop residues; food processing has what would otherwise be waste; shredded paper is good (the ink on printed paper is not toxic nowadays, but avoid glossy paper and fancy papers with metallic additions).

A worm bin is not a trash disposal – you need to find a recipe that combines your ingredients in the right proportions to provide a balance of nutrients. The ideal starting ratio is 25 carbon:1 nitrogen, and a helpful list is in the book. You can use an online compost calculator to roughly determine an appropriate mix. Pre-composting is a good way to turn your materials into a homogenous substance the worms will thrive on. This avoids the problem described by Rhonda as “the worms beeline for the melons and stay away from the onions.” Rhonda provides ten reasons for pre-composting.

Photo http://lessismore.org/materials/75-vermicomposting/

Earthworm husbandry is central to worm farming. Inspect daily with eyes and nose, and squeeze a handful of bedding to test for moisture. Never pour water directly into the bin “even if you have seen people do it on YouTube!” as Rhonda cautions. Once a week count population samples at 4″ (10 cm) deep. Take 6″ (15 cm) squares, count and record worm numbers and make sure numbers don’t go down. Keep your worms in a temperature range of 60-80F (16-27C), cooling, insulating or heating as needed. Adding extra feed will help raise the temperature in cold weather, but don’t overdo it. Add cow patties and see if your worms choose to congregate there. Add an insulating layer and watch out for other animals (“with sharp teeth!”) sheltering there. Be aware that too much cooked food can attract different types of flies.

 

Six worm bins.
Photo NCSU
https://composting.ces.ncsu.edu/vermicomposting-2/earthworms-and-worm-bins/

The instructions for harvesting worms, vermicompost or both are very practical. For small-scale enterprises with limited budgets there is the table harvesting method – spreading the top layer of the bin material on a table and hand-sorting worms, vermicompost and unconsumed food. This is made more efficient by using bright lights to cause the worms to cluster in the middle of the pile, avoiding the light. Another method, if you only want the worms, is to add fresh feed in a wide mesh tray on the top of the bed, after fasting the worms for a week. When the worms gather in the tray, scoop them up.

To harvest vermicompost, you can make screening boxes. Sort the finest vermicompost for sale or use on the farm, and return the coarser material and the worm cocoons to the bin. Return the worms to the bed or sell them. A way to harvest the vermiculture but not the worms is sideways separation. Set up a new bedding and feeding area adjacent to the old one, after not feeding the worms for a week or so. They will gradually move sideways into the better accommodation and you can harvest the vermicast from the old area. Continuous flow-through bins allow vermiculture harvest without disturbing the worms. This involves grates in the bottom of the bin and a way of scraping the vermicompost across the grate. This was the only place in the book where I do not understand the description, and there was no helpful diagram or photo. Fortunately a description later cleared up the mystery.

There is a good photo of a homemade trommel (cylindrical screen) involving bicycle rims. Worm farmers are definitely a hands-on crowd! Packaging and shipping can involve egg trays cut to size on a band saw, and breathable bags sewn from rolls of rowcover.

Vermicast can be tested using compost-testing criteria, and the book tells you the target values for pH and various elements and also the acceptable pathogen limits. There’s also a list of 13 bragging points which you can include on your label if selling your products. There is also a warning about what not to claim on you labels!

Rhonda Sherman

The last chapter of the book consists of 27 diverse global case studies, and makes inspiring and confidence-building reading. So many ideas you could use for your own worm farm! Rhonda points out that she herself is operating from a small research station, with a small staff. Sites profiled include the Len Foote Hike Inn (Georgia), a state park facility where you do indeed need to hike in. The facility was built in 1998 to be sustainable. The worm bins are fed guest meal scraps, shredded office paper, cardboard, discarded natural fiber clothes and even cotton mopheads! The Evergreen State College collaborates with Cedar Creek Corrections Center in Washington to recycle their food waste. The prisoners designed and built the equipment, saving the taxpayers $2000 per year and reducing the facility’s water consumption by 25%. The vermicompost is used in the prisoners’ garden to grow vegetables for the facility.

The Medical University of South Carolina reduced food waste with worms and has recorded the data in good academic fashion, providing everyone with some precise information on quantities, labor requirements, expenditure and productivity. Wright-Patterson Air Force Base (Ohio) began vermicomposting when they acquired a bin and a quarter-million earthworms from another air force base where they were no longer welcome. With one hour of labor per day, the staff were able to save $25/day hauling waste food and provide vermicompost for the base golf course (hey, better than chemical fertilizer!)

Photo
https://www.tagawagardens.com/blog/want-to-turn-kitchen-garbage-into-gardening-gold-vermicomposting-is-for-you/

Various school projects are acclaimed for educating children and getting them onboard with reducing landfill lunch components by 85%, in one case. After lunch, the SCRAP carts (Separate, Compost, Reduce and Protect) carts (operated by students, staff and custodians) are wheeled around to collect up whatever has not been eaten.

The Green Organic Agricultural Production Company in Kabul, Afghanistan, is a woman-owned business with the goal of composting and vermicomposting 20% of Kabul’s organic waste, and train other women in the process. They use open-air beds built of concrete blocks, producing 100 tons of vermicompost annually.

The diversity of the farms profiled is a real help in showing the process as manageable on various scales, in various climates and with varying degrees of funding and mechanization. Perhaps the widest range is the feedstocks: everything from manures and vegetable wastes to agave bagasse at a tequila production plant, waste from a palm oil extractor plant. And scales up to 200,000 tons per day (maybe bigger). Reading these profiles will also steer you away from repeating mistakes already made by others, such as the large continuous flow-through bin made of wood, that fell apart under the strain, dumping worms and vermicompost on a concrete floor in the middle of winter in Michigan.

Corrugated cardboard is a surprising source of nitrogen – it’s in the glue. As paper is recycled, the fibers get shorter each time until they are too short to be useful for recycling (this is why egg boxes and apple trays are not recyclable. Worm farming is the perfect use for these products, and worms are partial to paper sludge.

There are five pages of Resources, nine pages of Bibliography and a twelve page Index. That’s an impressive index. Twin Oaks runs an indexing business, and I have written two books myself, so I have a fine appreciation of indexes!

Our Organic Integrated Pest Management

French Marigolds and sesame to combat root knot nematodes in our hoophouse.
Photo Pam Dawling

Organic Integrated Pest Management involves tackling pest problems one step at a time with ecologically-based practices, starting with actions chosen to reduce the chances of the pest ever getting a grip on your crops.

Steps:

  1. Cultivate a good environment for your crops: healthy soil, sufficient space, nutrients and water, suitable temperature, soil pH. Practice crop rotation to reduce the chances of pests and diseases carrying over from one crop to the next. Clear old crops promptly, so they don’t act as a breeding ground for the pest. Choose suitable varieties that resist the pests you most expect.
  2. Cover or protect the plants physically from the pests (mulches to stop soil-dwelling pests moving up into your crops, netting, rowcover, planting diverse crops, and even trap crops)
Young cucumber plant under insect netting in June.
Photo Pam Dawling
  1. Provide habitat for natural enemies and other beneficial insects
  2. Monitor crops regularly at least once a week and identify any pests you see.
  3. Introduce natural enemies of the pest (bacteria, fungi, insect predators or parasites)
  4. Hand pick (or trap) and kill the pests if the pest population is above the action threshold. Many fruit and root crop plants can take 30% defoliation before any loss of yield. Where the crop is the foliage, this may be too much!
  5. Use biological controls (often derived from natural enemies) if the damage is still economically significant after trying the earlier steps in the process.

I recommend the ATTRA online publication Organic Integrated Pest Management.

Each of the 22 pages is a poster, complete with good photos and concise clear info.

Our motion sensor sprinkler and the outer layer of our fence around the sweet potato patch at the end of May. The inner fence was installed later.
Photo Pam Dawling

One of our biggest garden pests is the deer, which are especially fond of sweet potatoes. We use motion-sensor water sprayers initially or in years when the deer pressure is low. For worse years we install an electric fence with a solar-powered charger.  Last year our electric fence didn’t keep the deer out, so this year we have a double layered fence to make sure.

Broccoli bed with alyssum to attract aphid predators.
Photo Pam Dawling

At the other end of the size scale are aphids.  We plant sweet alyssum in our beds of broccoli and cabbage to attract insects that will eat aphids. We sow about 200 plugs for 1500 row feet (450 m) of brassicas planted as two rows in a bed, and pop one alyssum plug in the bed centers every  4ft of bed or about one alyssum per  4 plants. We transplant these the same day that we replace any casualty broccoli and cabbage plants.

Nasturtiums planted in with squash to deter pests. Does it work?
Photo Pam Dawling

We transplant some bush nasturtiums in with our first plantings of cucumber and summer squash. They are said to repel some cucurbit pests such as squash bugs., but I can’t vouch for that. Radishes in cucumber or squash rows are said to repel cucumber beetles and squash bugs. I haven’t tried that. There are a lot of companion planting ideas out there, but most have no scientific evidence for effectiveness.

An insectary circle in early June. The flowers will attract beneficial insects.
Photo Pam Dawling

In late May or early June, we transplant some flowers in our garden to attract pollinators and pest predators. We use circles cut from plastic buckets to surround these clusters of flowers so that inexperienced helpers don’t pull them out as weeds.  We use a combination of sunflowers, dill, borage, cosmos, calendula, tithonia (Mexican sunflowers), zinnias.

Sunflower bee and bug.
Photo by Bridget Aleshire

We also sow sunflowers in our bean beds at each succession. These attract birds and pollinators, while also acting as landmarks for our harvest progress.

In our hoophouse we have been tackling nematodes for several years. This year we have planted the nematode areas in French marigolds and sesame (apparently particularly good in deterring root knot nematodes, the type we have.) Some other nematode areas have been planted with Iron and Clay cowpeas. Unfortunately we now have an aphid infestation on the cowpeas! We are trying blasting the aphids off the plants with a strong stream of water from a hose. Later in the summer we will solarize some of the nematode areas.

We planted Iron and Clay cowpeas to deter nematodes, but got aphids!
Photo Pam Dawling
Flowering sesame in our hoophouse, surrounded by French marigolds. We hope they will fight the root knot nematodes.
Photo Pam Dawling