Heads up everyone saving seed from their tomatoes, melons, or squash this year, in anticipation of possible seed shortages next spring! Or because you have the time at home to figure out how to do it, and you’re around to stir the bucket three times a day! I have an article on wet seed processing in the August issue of Growing for Market magazine.
The next issue will have my article on dry seed processing (think beans, peas, okra, lettuce).
The current issue also has a couple of interesting articles on how to move step-by-step towards no-till growing, or at least minimum-till. Many gardeners and farmers have floundered while making this transition, so learn from the experienced! And there’s an article by Julia Shanks on balance sheets, for those intending to make a living farming.
Or choose the 2020 all-access course bundle of 21 courses (over 100 videos) for $150.
Or before summer is over, go for the $120, 8 course (56 videos) Summer Bundle.
What went wrong with our hoophouse peppers in 2020?
Our 2020 hoophouse peppers were stunted, crinkled, yellowing and failed to thrive.
Too cold in edge bed A (drafts under baseboard)?
Too wet in bed A (rainwater under baseboard, not much drying out due to shade of tomatoes)?
Nutsedge poisoning: roots exude something that inhibits other plants?
Soil too salty?
Soil nutrients poor?
Aphids spread a virus? (plants were crinkled)
Are we sowing hoophouse peppers too early? In cells that are too big?
Are we transplanting hoophouse peppers too early? Keeping them in in cells that are too small?
Be sure to block drafts all winter. Try not to plant peppers in cold edge beds.
Close one row of driptape if soil in edge bed A seems excessively wet compared to other beds. Re-dig outside moat to keep soil water out.
Do better about weeding out nutsedge. Investigate soil properties that encourage nutsedge.
Use beds C and E instead of middle bed D when doing salt water wash down. Poke out holes in sprinkler, ensure all are working. Get a better sprinkler.
Do soil tests in October and remediate soil as needed.
We could monitor for pests and act promptly
Deal with aphids and avoid viral diseases
Sow later, in smaller cells.
Transplant later, after potting up to bigger cells or pots.
Summary of ideas after our meeting and reading 2020 records:
Use fresh seed
Go back to deep 6 cells for sowing, (smaller than R38)
Use more appropriately warm growing conditions. Peppers don’t recover well from setbacks. They remain stunted long term.
Test soil and act accordingly.
Ensure salt wash-down reaches the edge beds.
If planting in chilly edge beds, ensure the baseboards are not drafty.
Remove nutsedge whenever we see it
Monitor for pests; deal with aphids to avoid long-term virus diseases.
Hoophouse Pepper Records Research
We have been sowing 2/3 for a 4/7 transplant date. That’s maybe too long. 9 weeks.
2/3/20 Hphs peppers sown as scheduled. Used R38s rather than usual deep 6s. It’s recommended not to sow peppers in large cells – they are slow growing, and it’s hard to get the watering right in large cells.
2/11 -2/14 Peppers germinated. We had some trouble with keeping the germinating chambers up to temperature because we didn’t have the right lightbulbs.
2/15 – 2/17 Heat mats not all plugged in or working right.
2/21 resowed Gilboa. PeaceWork was old seed, poor vigor? Or low germ rate?
2/28 Gilboa resows had been in tent but weren’t actually germinated. Back in fridge.
3/4 – 3/9 Potted up. Is this true? R38s don’t normally get potted up. Maybe due to patchy germination?
3/16 In ghs drafty zone
4/5 Ghs door left open all night
4/12 Ghs door left open all night again.
Info from Sustainable Market Farming and The Year-Round Hoophouse
Sow 8-10 weeks before you intend to transplant.
We used to sow our hoophouse peppers 1/17, then 1/24, then 1/31, then 2/3.
Minimum temperature for germination is 60F, optimum 68-95F.
Peppers seem to produce stockier plants if soil temperatures are 65-68F, max 80F daytime, min 60F at night after germination. Use a soil thermometer.
Transplants getting slightly cooler nights will grow sturdier plants that flower later and have more potential for big yields. Rowcover at night if 40F or below.
After third true leaf, can reduce night temp to 54F. May increase yields.
But, permanently stunted by conditions that are too cold.
Keeping them in pots or cells that are too small will set them back. If transplanting is delayed, pot up to larger size, eg tomato pots.
Pot up when a few true leaves appear. After that no heat mat needed.
We moved our transplanting date from 4/1 to 4/7 (one week after tomatoes is usual)
Transplant at 6-9 weeks, with 4 or 5 true leaves, not yet flowering. OK if they are big.
Soil for transplanting should be at least 60F, ideally 68F
Avoid transplant shock. Soil needs to be damp before, during and after transplanting. Avoid root damage or bending. Shade if hot, sunny or breezy.
For the first week after transplanting, keep warm.
Established peppers benefit from 70-75F days, 64-68F nights
Maintain sufficient levels of boron, calcium, phosphorus.
Monitor and control aphids and thrips to prevent the diseases they vector.
An inch of water per week is about right.
Foliar feeding with fish or seaweed emulsion once a week after fruit set.
65-80 days from transplant to full-size immature fruits, and another 2-4 weeks to ripe fruit.
Yields should be 5-18 lbs/10ft.
Ideas after rereading those sources
We might do better to set the sowing date a week later (2/10), keep the transplant date at 4/7 and aim for an 8 week-old transplant? (Avoid colder conditions)
We need to pay more attention to temperatures of germination, seedlings and potted transplants. Write the goal temperatures on the Seedlings Schedule
We need to pay more attention to not overwatering seedlings. Write that on the Seedlings Schedule too.
Sow summer cover crops while it’s still too early sow your winter cover crops. Sow oats 5-8 weeks before your average first frost to get good size plants before they get winter-killed. Sow winter rye from 14 days before to 28 days after first fall frost. Oats, barley, wheat and rye sown too early can head up and seed before you get to winter, making them less useful. Instead, sow fast-growing summer cover crops in any space possible, for weed suppression and a boost to soil organic matter.
Keep live roots in the ground as much of the time as possible, to feed the microorganisms and anchor the soil, preventing erosion in heavy rains. Dead roots also have a role, providing drainage channels in the soil and letting air in deeper. Adding organic matter to the soil is a way of banking carbon, as well as providing nutrients for your crops.
Deep-rooted cover crops draw up nutrients, bringing them up where crop plants can access them. Leguminous cover crops provide nitrogen, saving imports of organic fertilizers or a big compost-making operation.
Advantages of Summer Cover Crops
Suppressing weeds. Weeds grow fast in summer, and fast-growing summer cover crops will suppress them. Sowing cover crops helps us stay on top of developing problems.
Growing biomass. Many summer cover crops can be mowed or scythed down (before flowering) to encourage regrowth. The cut biomass can be left in place, or raked out and used as mulch in another part of the garden. Some can even be used as feed or bedding for small livestock.
Feed the soil life. Cover crops are solar-power generators, transforming sunlight, water and carbon dioxide into leaves and roots. They also release carbohydrates and other nutrients that feed soil microbes, earthworms and other soil life forms that make soil fertile. This cycle of nutrients constantly passes through plants and back into the soil. When you aren’t growing vegetable crops, cover crops keep this cycle going.
Increasing biodiversity. Cover crops can attract beneficial insects, birds and amphibians to feed and reproduce. Biodiversity encourages ecological balance that can help reduce plant diseases and pest attacks.
No-Till summer cover crops. A mix of soybeans or southern peas and foxtail millet can be grown during the summer and mow-killed before planting in the fall. Garlic perhaps?
Overcoming the Challenges of Summer Cover Crops
Finding space. If you’ve been carefully filling every space with vegetables, you may think you have no room for cover crops, but because they feed the soil, it’s worth making space for them too. It’s part of the wholistic picture of sustainable food production. It’s worth making a priority to have one bed or one section of your garden in cover crops, because of what they can do for your soil.
Have a goal of No Bare Soil. Seek out odd spaces to fill with cover crops.
Use space beside rows of sprawly crops short-term. Undersow buckwheat in winter squash, watermelon or sweet potatoes, and mow or till as soon as the vines start to run.
Take a cold hard look at aging crops: better than keeping an old row of beans to pick every last bean, is to pull up those beans and sow a quick cover crop. It will be a more valuable use of the space.
Take a look at your planting plan. When is your next crop going in that space? Rather than till the soil to death to manage the weeds, use a cover crop. In the winter, see if you can re-arrange your crop rotation and planting plan to make more time windows of a month or more, with the plan of using more cover crops.
Undersow growing crops with a cover crop when the vegetable crop has been in the ground for about a month. The food crop will be big enough to resist competition from the cover crop, and the cover crop will still get enough light to grow. This way fewer weeds grow, and your cover crop is already in place when the food crop is finished, giving it longer to reach a good size. We undersow our sweet corn with soybeans (soy and oats for the last sweet corn planting). Buckwheat can be under-sown in a spring vegetable crop, to take over after the food crop is finished. You can plant a short cover crop on the sides of a bed of any tall crop like tomatoes or pole beans. You will need to provide extra water, especially while the cover crop is germinating. Read my Mother Earth News post on undersowing in late summer and early fall.
You can also undersow winter cover crops during late summer and early fall to last over the winter and even the next year. We broadcast clover among our fall broccoli and cabbage with the plan of keeping it growing for the whole of the following year, mowing once a month to stop annual weeds seeding.
High temperatures. Most summer cover crop seeds will germinate just fine at high temperatures provided they get enough water.
Drought. If it doesn’t rain much in your summers, or your irrigation water is limited, choose cover crops that are drought-tolerant once germinated. After sowing, work the seed into the soil and roll or tamp the soil so that the seed is in good contact with the soil, which will help it get the water it needs rather than drying out in an air pocket. To get good germination, keep the soil surface visibly damp. You can use shadecloth, a light open straw or hay mulch, or even cardboard to reduce evaporation. Be sure to check every day and remove the cardboard as soon as you see the first seedlings.
Sowing small spaces. You can sow cover crops in rows by hand in very small spaces, or use an EarthWay seeder. Or you can broadcast: tuck a small bucket of seeds in one arm, take a handful of seeds and throw them up in front of yourself in a fanning movement, trying not to spread seed into neighboring beds where you don’t want them. Aim for about two seeds/sq in (1 sq inch is 6.5 sq cm, I’ll leave you to think what it looks like). Don’t sweat the details, you will get better with practice! This isn’t brain surgery! For more even coverage, try broadcasting half the seed walking up and down the length of the patch, then sow the other half while walking at 90 degrees to your original direction. Rake or till the seeds in, trying to cover most of the seeds with 0.5-1” (1-2.5 cm) of soil. Water with a hose wand or sprinkler to keep the soil damp until germination.
Working with the time you have left.
If you have only 28 days until the patch is needed for a food crop, you can grow mustard or buckwheat. Or weeds, if you’re careful not to let them seed!
If you have at least 45 days, you can grow soy or Japanese millet.
If you have only 40-60 days before frost you can sow oats with soy beans or spring peas as a winter cover crop to winter-kill.
If you have 50–60 days until frost, or between crops, Browntop millet is possible. In the right climate, sunn hemp can mature in 60 days.
With 60–80 days until frost, or between one crop and the next, you could sow buckwheat, soy, southern peas, spring peas, German foxtail millet, pearl millet, Japanese millet, or sorghum-sudangrass to frost-kill. Or you could sow oats with Austrian winter peas, crimson clover, or red clover to grow into winter.
If you have longer than 80 days you can sow any of the warm weather cover crops now and then move on to winter cover crops 40 days before your frost. Or you could sow a fast-growing vegetable crop.
Five Easy Summer Cover Crops that Die with the Frost
Buckwheat is the fastest and easiest cover crop, a 2’-3’ (60-90 cm) tall broadleaf annual that can be flowering within three weeks in very warm weather, 4 weeks in regular warm weather. Because it grows so fast, it quickly crowds out germinating weeds. Plant buckwheat after all spring frosts have passed, until 35 days before the fall frost at the latest.
If you have longer than 4 weeks for cover crops, you have the option of letting the buckwheat self-seed and regrow (only do this if you’ve finished growing vegetables for that year in that space). Another option if you are not close to the frost date is to incorporate the buckwheat in the soil and then sow fresh seed.
Buckwheat is very easy to incorporate into the soil. Use a mower or scythe to cut it down 7-10 days after it starts flowering, and then either let the dead plants die into a surface mulch and plant into that, or rake it up and compost it, or dig or till it into the soil. For small areas, you can simply pull up buckwheat by hand – this is what we do in our hoophouse.
Buckwheat can be used as a nurse crop for fall-planted, cold-tolerant crops, which can be difficult to germinate in hot weather. Sow a combination of buckwheat and a winter vegetable to shade and cool the soil. When frost kills the buckwheat, the vegetable crop can continue growing with no competition.
Buckwheat is not related to any of the common food crops, and so it is simple to include it in crop rotations.
One of our favorite summer cover crops is sorghum-sudangrass, a hybrid that grow 5’-12’ (1.5-3.6 m) tall in 60-70 days and produces an impressive amount of biomass. You’ll need big machinery, at least a big BCS mower, to deal with sorghum-sudangrass. If you have only hand tools and a lawnmower, I recommend growing German foxtail or Japanese millet instead.
Plant sorghum-sudangrass about two weeks after your first sweet corn planting date and anytime onward until six weeks before frost. After it’s established, sorghum-sudangrass is highly drought-resistant and thrives in summer heat. Plant in rows 8” (20 cm) apart, with seeds 1’ (2.5 cm) deep, 1.5” (4 cm) apart. Sorghum-sudangrass will smother weed competition, and make big improvements to the soil texture and the levels of organic matter.
When the sorghum-sudangrass reaches 4’ (1.2 m) tall, cut it down to 1’ (30 cm) to encourage regrowth and more, deeper, roots growth that will loosen compacted soil. The cut tops make a good mulch, or you can leave them in place.
Sorghum-sudangrass roots exude allelopathic compounds that suppress damaging nematodes and inhibit small seeds (weeds and crops) from germinating and inhibits the growth of tomatoes, lettuce, and broccoli. Wait at least 6 weeks after killing sorghum-sudangrass before planting another crop in the same spot. Plant earlier at your own risk – I think we’ve had some success despite the warnings. Be careful if feeding to livestock. Read up about prussic acid poisoning from this cover crop.
These are a quick easy leguminous cover crop for warm weather. Buy organic seed if you don’t want GMOs, as almost all non-Organic soybeans in the US are GMOs. We plant these whenever we have a minimum of six weeks for them to grow before frost or before we’ll need to turn them under. They aren’t the highest N-producing legume, but they are very fast-growing and easy to manage.
Also known as cowpeas, although I have heard this might be perceived as insulting by African-American families who use them as food. Southern peas grow fast (60-90 days), thrive in heat, and are very drought-tolerant. Their taproots can reach almost 8’ (2.4 m) deep. They grow well in almost any soil, except highly alkaline ones. Southern peas attract beneficial insects.
Sow southern peas 1-2 weeks after your sweet corn, when the soil has warmed up. You can continue sowing until 9 weeks before a killing fall frost. Sow seeds 2” (5 cm) apart, 1” (2.5 cm) deep in rows 6” (15 cm) apart (give vining types more like 15” (40 cm) between rows. Close planting is needed to shade out weeds.
Because they are fast-growing, southern peas can follow spring vegetable crops and fix nitrogen in time to feed heavy-feeding, fall-planted onions or garlic.
Sunn hemp is a nitrogen-fixing legume from the tropics, which can grow as much as 9’ (2 m) tall in just weeks. Sow sunn hemp from 1-2 weeks after your sweet corn sowing date, up to 9 weeks before a killing frost. It tolerates a wide range of soils (but not if waterlogged), and dies with the frost. Plant inoculated seed (use the same inoculant as for southern peas) 1” (2.5 cm) deep, with seeds 1.5” (4 cm) apart in the row, and with rows 6” (15 cm) apart. Sowing densely will smother the weeds.
If you sow in a summer gap between spring and fall vegetable crops, it will provide a nitrogen boost for the fall crop. In dense plantings, it can fix more than 120 lbs (54 kg) of nitrogen and 12 pounds of biomass per 100 sq ft (0.56 kg/sq m). 60 days after sowing, the stems thicken and become fibrous and high in cellulose; cutting at this stage produces long-lasting mulches that increase soil carbon. If you cut the crop back at a younger stage, this will stimulate branching (more biomass) and more root penetration (better drainage).
Late Summer Cover Crops for Winter: Oats and Barley
In late summer you can sow oats for a winter cover crop that will be killed at 6°F (-14°C). We sow in late August and early September in Zone 7. Inexpensive and easy to grow, oats are a standard fall cover crop: a quick-growing, non-spreading grass, oats will reliably die in Hardiness Zone 6 and colder, and nine years out of ten in zone 7.
Barley grows even faster than oats, and on average it will get killed later in the winter. It usually dies at 17°F (-8°C), making barley another choice for gardeners in regions where oats are used.
Cover Crop Resources
My book Sustainable Market Farming has a chapter on cover crops and 9 pages of charts about particular options.
The book Managing Cover Crops Profitably (third edition) from the Sustainable Agriculture Research & Education Program (SARE), is the best book I know on the subject. You buy the book for $19 or download it as a free PDF from SARE.
For years I have been mentioning “Miami Peas” in my presentations about cover crops. At the Carolina Farm Stewardship conference I was asked what they are, by Mark Schonbeck, who knows cover crops well. (This is one of the wonderful benefits of attending conferences – meeting peers and mentors, and learning new things.)
I said it is a frost tender cover crop pea of the field pea type (not a southern pea). I can’t remember where I first heard about this cover crop, and we haven’t been using it on our farm, so it was time for a reality check when I got home. I can’t find any reference to Miami peas apart from the ones I’ve made! I believe it’s a type of Canadian field pea, but maybe it no longer goes by the Miami name, or maybe it never did! It’s embarrassing to promote untruths.
This short term green manure smothers weeds well and adds nitrogen and other nutrients to the soil. Peas are often mixed with vetch, oats, or rye as an effective cover crop. The sprouts are delicious and you can even harvest the peas themselves for soup. This annual prefers cool well drained soil and has no frost tolerance. Sow 3 to 4 lbs per 1000 sq. ft.
For clarity, here’s what I now believe:
“Forage pea” and “Field pea” are terms that include the hardy Austrian winter peas, that we do use and are big fans of, as well as frost-tender spring peas, also known as Canadian field peas.
SARE lists Canadian field peas as Spring Peas. SARE is a very reliable source of information. They say
These annual “spring peas” can outgrow spring-planted winter peas. They often are seeded with triticale or another small grain. Spring peas have larger seeds, so there are fewer seeds per pound and seeding rates are higher, about 100 to 160 lb./A. However, spring pea seed is a bit less expensive than Austrian winter pea seed. TRAPPER is the most common Canadian field pea cultivar.
Other spring pea varieties are Dundale and Arvika
There’s also a tropical Pigeon Pea, Cajanus cajan, which can grow in the Southern US, but that looks pretty different, and I don’t think that’s what I meant.
Forget industrial hemp
I have been alarmed at how many small-scale growers are trying industrial hemp. Partly I’m hoping it won’t cause a shortage in locally grown food! I also wonder how well an industrial field crop grows on a small scale, and how the growers would deal with the permits, the processing and the marketing.
Read this report from The Modern Farmer about how industrial hemp is unsuccessful for most growers and how the market is swamped with would-be suppliers:
I have had a little flurry of arranging workshops, so if you have (educational) travel plans, check out my Events page. I’ve also got two interviews lined up, for podcasts, and I’ll tell you about those when they go online.
Use cover crops to feed and improve the soil, smother weeds, and prevent soil erosion. Select cover crops to make use of opportunities year round: early spring, summer, fall and going into winter. Fit cover crops into the schedule of vegetable production while maintaining a healthy crop rotation.
In the Main Conference, on Sat Nov 2, 1.30 – 2.45 pm in the Empire Ballroom E, I have a 75 min workshop
Optimize your Asian Greens Production
This workshop covers the production of Asian greens outdoors and in hoop houses in detail, for both market and home growers. Grow many varieties of tasty, nutritious greens easily and quickly, and bring fast returns. The workshop includes tips on variety selection of over twenty types of Asian greens; timing of plantings including succession planting when appropriate; crop rotation in the hoop house; pest and disease management; fertility; weed management and harvesting.
I will be participating in the Booksigning on Saturday 5.45 – 6.45 pm during the reception
Winter Cover Crops
Cover crops have been much on my mind. Partly it’s that time of year – too late for us to sow oats, not so late that the only option left is winter rye. Here’s my handy-dandy visual aid for central Virginia and other areas of cold-hardiness zone 7a with similar climates.
If you are considering growing winter rye as a no-till cover crop this winter, check out this video:
Rye Termination Timing: When to Successfully Crimp, by Mark Dempsey
“Interested in no-till production, but unsure of how to manage cover crops so they don’t become a problem for the crop that follows?
The most common management concern is when to crimp your cover crop to get a good kill but prevent it from setting seed. Getting the timing right on crimping small grain cover crops like rye isn’t difficult, but it does take a little attention to its growth stage. See this three-minute video for a quick run-down on which stages to look for in order to get that timing right.”