Cover Crops for April: before the last frost.

 

Beds of young buckwheat.
Photo Bridget Aleshire

In January I shared some resources to give the Big Picture of Cover Crops, including a compilation of slides for SARE (Sustainable Agriculture Research and Education) and my slideshow Cover Crops for Vegetable Growers.

In February, I described limiting winter annual weeds by sowing oats in spaces without a cover crop and no planned food crop for 6-10 weeks. Six–ten weeks (depending on your climate) is long enough in early spring to get worthwhile growth from oats before prepping for the food crop. Also see February’s post for the Stale Seedbed and Tarping Techniques.

In March I wrote about some options for cover crops you might be sowing then, and alternatives like a fast-growing hardy leafy vegetable or mixed Eat-All Greens, an idea from Carol Deppe, a great idea if you have more than eight weeks before your main vegetable crop goes in the ground. This is where using transplants really helps increase your total food output. While the frost-tender transplants are growing indoors, you could be growing a “catch crop” outdoors in spaces that didn’t get a winter cover crop. I also talked in the March post about incorporating cover crops. Remember that if you incorporate fresh green cover crops into the soil, you will need to wait two or three weeks to sow, to give the cover crop time to break down in the soil before it can be available for your crop. Especially, wait three weeks after turning under winter rye before sowing, as it produces allelopathic compounds that can inhibit the germination and growth of small seeds. Transplants don’t suffer the same problem.

Potatoes, weeds and standing water. Until the soil drains, the potatoes cannot be hilled, and the weeds here are already large. The yield will be reduced by weeds out-competing the potatoes. Potatoes may be flamed at 6″–12″ (15–30 cm) tall, to kill weeds without damaging the potato plants. After that, flaming is not recommended.
Photo Bridget Aleshire

Once we get to April here, it is too late to successfully grow oats (they will quickly head up after making very little growth). But in climates like ours, we can sow winter wheat or winter rye in April – they will not head up, but will “wimp out” when it gets hot. That is, they will stop growing, so you won’t get a lot of biomass, but you will have some live roots in the soil, holding it together, taking care of the soil microfauna, and discouraging weeds form germinating. One April when our spring-planted potatoes got flooded, we transplanted potato plants to the drier end of the patch and sowed winter rye in the lower end, once the floods had subsided. This kept the soil covered, scavenged the compost we had spread for the potatoes, and was easy to deal with in July when we harvested the potatoes. It was also much more hopeful to look at an area of green cover crop than an area of green weeds!

April is too soon for us to rely on frost-tender cover crops, but by mid-April, we can sow a mix of oats and buckwheat. The oats will protect the buckwheat somewhat from the cold. if the season is warmer than average, the buckwheat will survive and smother weeds, provide pollen and nectar for beneficial insects

Here’s a lovely quote from Barbara Pleasant in SW Virginia:

“It’s April and the soil is warming up and drying out. After loosening a clump of fall-sown wheat with a digging fork, you pull up a marvelous mop of fibrous roots and shake out the soil. What crumb! The soil’s structure is nothing short of amazing! These are the moments an organic gardener lives for.”

Root systems of four grass cover crops at early stages of growth (two months in a greenhouse). From left: annual ryegrass, barley, triticale (winter biennials) and sorghum-sudangrass (summer annual). Photos by Joseph Amsili. From SARE

Depending on the stage of the year where you are, you could revisit any of the earlier posts. Here are links for each of the cover crop posts in the past year.

May: Buckwheat and Other Summer Cover Crops

June: Sunn Hemp, Soybeans, Southern Peas, and Partridge Pea, Senna Ligustrina

July: Millets and Sorghum-Sudangrass (Sudex)

August: Oats, Barley and Other Winter-Killed Cover Crops

September: Winter Wheat and Crimson Clover

October: Winter Wheat and Austrian Winter Peas

November: Winter Rye (with Austrian Winter Peas early in November)

December: Planning Winter Cover Crops

January: The Big Picture, Ponder and Plan Your Cover Crop Strategies for the Coming Year

February: Oats if you have a 6–10 Week Gap

March: Sowing Options and Incorporating Cover Crops

Perennial and Native Cover Crops

I attended a workshop at the VABF-SFOP Summit on cover crops led by Cerruti R2 Hooks, Veronica Yurchak, from the Department of Entomology, University of Maryland, and Hanna Kahl of UC Davis. The UMD Eastern Shore IPM Center has lots of useful programs and publications. They focus on the most important pest problems and make science-based information available to everyone who contends with pests. This workshop discussed how cover crops influence weeds, plant diseases and insects. Cover crops can smother weeds, augment weed seed predators (lifeforms that eat weed seeds), create a weed-suppressive soil microbe community, release allelochemicals that are toxic to weed seeds, release nitrogen into the crop germination zone, boosting crop growth, cool the soil and compete with weeds for resources.

Cover crops can decrease crop diseases by increasing the diversity of soil organisms, making soil more disease-suppressive; releasing compounds unfavorable to disease organisms; trigger plant immune responses; increase the number of beneficial organisms and forma physical barrier that reduces splash-back from the oil. A nice example is that sunn hemp interplanted in squash rows can cause aphids carrying virus particles in their mouth parts to drop them in the sunn hemp where they do no harm.

Sunn hemp at Nourishing Acres Farm.
Photo Pam Dawling

Cover crops can repel some insects and nematodes, as well as providing habitat, nutrients and protection from predators for the beneficial insects. This can help augment the population of beneficial insects. Cover crops can also act as trap crops for problem insects by being more attractive to them than the crop plants. Cover crops can also cause microclimate change within the crop, for example by acting as a windbreak.

The speaker gave examples with red clover, a short-lived perennial, sown in the previous fall between cucumber rows that were planted in spring. The population of striped cucumber beetles was lower, while populations of beneficials such as big-eyed bugs, minute pirate bugs and ladybugs were increased.

In November 2023, at the Carolina Farm Stewardship Conference, I went to an engaging workshop called On-Farm Cover Crops Research in the Carolinas by Justin Duncan from NCAT/ATTRA, Jason Lindsay from the Southeastern African American Farmers’ Organic Network, and Steve McAllan. See his YouTube  Cover Crops for Hot & Humid Regions. At the workshop, Justin Duncan explained Push-Pull Trap Cropping, invented in Kenya, combining a companion plant that repels a pest with a trap crop nearby that attracts it, making pest control easier.

Pigeon Pea as cover crop. Photo https://conservationist.wordpress.com/2008/11/03/pigeon-pea-as-cover-crop/

He advocated for pigeon peas (Cajanus Cajan) as a cover crop for warm droughty climates, that will also keep the soil cooler. When mean temperatures rise 1 Celsius degree, soils in warm areas burn up 10% of their OM, and cool areas lose 3%. Loss of water leads to loss of OM, leading to more water loss. Hot humid areas need twice as much OM as cooler ones to maintain fertility. No-till can cut the loss of OM by half compared to conventional tillage. Other cover crops Justin Duncan recommended include Perennial Peanut, good in orchards, Chamaecrista rotundifolia (round-leaved cassia) and Scarlet Runner beans. Cover crops are a way of growing Organic Matter in place.

Patrick Johnson, RVA Permaculture. Photo https://rvapermaculture.com/about-us/

Patrick Johnson, a Virginia permaculturist, also gave a presentation on native cover crops. See his Proposal and Project Overview:  https://projects.sare.org/sare_project/fs22-345/

And read the Feb 2024 SARE report Using a Native Legume as a Cover Crop for Soil and Vegetable Production Benefits in Small Scale Vegetable Production.

No-Till Cover Crops

I have not covered these yet, and don’t have much personal experience, apart from our one-year-in-ten growing of paste tomatoes in a mow-killed rye, hairy vetch and Austrian winter peas dying mulch. I’ll make a separate post for next week about combining cover crops and no-till methods.

Cover Crop Training Videos from SARE

See SARE for a series of ten training videos.

Weeds Next

For my next annual series of blogposts, starting at the beginning of May, I will cover Weeds of the Month.

Cover Crops for March: Sowing Options and Incorporating Cover Crops

In March, where we undersowed clovers in the broccoli patch in August, the old broccoli trunks are surrounded by a sea of green clover.
Photo by Kathryn Simmons

In December I wrote about Cover Crop Planning for Next Year, including 5 steps of cover crop planning for all opportunities. I have a slideshow Crop Rotations for Vegetables and Cover Crops, which I find to my surprise that I haven’t posted here since my 2014 version.

Here it is now

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In January I shared some resources to give the Big Picture of Cover Crops, including a compilation of slides for SARE (Sustainable Agriculture Research and Education) and my slideshow Cover Crops for Vegetable Growers.

In February, I described limiting winter annual weeds by sowing oats in spaces without a cover crop and no planned food crop for 6-10 weeks. Six–ten weeks (depending on your climate) is long enough in early spring to get worthwhile growth from oats before prepping for the food crop.

This month I will include some options for cover crops you might sow in March (in central Virginia and similar climates), and then talk about incorporating cover crops, which surely you will be doing this month!

Cover crops to sow in March, and other options

Purple stemmed mizuna. Mizuna and other frilly mustards are fast-growing crops, attractive to the eye and the palate.
Photo Pam Dawling

Depending on the stage of the year where you are, you could revisit any of those posts.

  • In early March the oats plan still works for us.
  • In early spring, the air and the soil are cold, and sowing a fast-growing vegetable crop will not be successful with a gap of less than eight weeks. Crops take too long to grow at this time of year.
  • If you have more than eight weeks you could try those fast-growing vegetables: kale, spinach, Tokyo bekana, radishes, chard, lots of salad crops, senposai, mizuna, tatsoi, land cress. Or try Eat-All Greens, an idea from Carol Deppe. Patches of carefully chosen cooking greens are sown in a small patch. When it reaches 12″ (30 cm) tall, Carol cuts the top 9″ (23 cm) off for cooking, leaving the tough-stemmed lower part, perhaps for a second cut, or to return to the soil.
  • In late March or April in climates like ours, we can sow winter wheat or winter rye – they will not head up, but will “wimp out” when it gets hot. That is, they will stop growing, so you won’t get a lot of biomass, but you will have some live roots in the soil, holding it together and taking care of the soil microfauna, and discouraging weeds form germinating. One year when our spring-planted potatoes got flooded, we transplanted potato plants to the drier end of the patch and sowed winter rye in the lower end, once the floods had subsided. This kept the soil covered, scavenged the compost we had spread for the potatoes, and was easy to deal with in July when we harvested the potatoes. It was also much more hopeful; to look at an area of green cover crop than an area of green weeds!
  • Once we get to March 31 here, it is too late in the year for us to sow oats (they will quickly head up after making very little growth) and too soon to rely on frost-tender cover crops. See the section in February’s post on the Stale Seedbed and Tarping Techniques.

    Tarping beds to kill weeds.
    Photo Cornell Small Farms Unit
  • By mid-April, it is an option to sow a mix of oats and buckwheat. The oats will protect the buckwheat somewhat from the cold. I’ll come back to that idea next month.

Incorporating cover crops, or not

See Barbara Pleasant: How to Take Cover Crops Down. Gardeners working with small tools can start by mowing their live cover crops, grazing poultry on them, or scything them and hauling them aside to use later for mulch. On a very small scale, you can pull your cover crop plants, although I think it is valuable to leave the roots in the soil. On a larger scale, you can graze larger animals, or cut the cover crop down. If the cover crop was winter-killed, the stems will easily disintegrate, so you can skip the cutting down part of these instructions.

If you plan to incorporate the cover crop, choose a mowing method that cuts the plants into small pieces, making them easier and faster to incorporate. On a small scale, this could be a weed whip or a lawn mower; on a larger scale a bush hog. If you plan to use the cover crop for mulch, cut it in a way that leaves the stems as whole as possible. On a small scale this means a sickle or scythe, on a bigger scale, the kind of machinery you might use to cut hay.

Cover crop of rye, vetch and crimson clover in March.
Photo Kathryn Simmons
Rows of Roma paste tomatoes, some on bioplastic, some no-till. Credit Bridget Aleshire

After getting the cover crop down, you could tarp for a minimum of three weeks (allow for more), or you could work the residue into the soil, with a chopping hoe or by digging it in, or using a walk-behind two-wheel tractor such as BCS with a rototiller or a power harrow, or a four-wheel tractor and discs. Cornell has posted a webinar Pairing Tarping with Cover Crops, by Brian Marr.

If you incorporate the cover crop into the soil green, you will also need to wait two or three weeks (or more in early spring) to plant or sow, to give the cover crop time to break down in the soil before it can be available for your crop.

Winter rye produces allelopathic substances that can temporarily inhibit the germination and growth of small seeds. Wait three weeks after turning under before sowing. Transplants don’t suffer the same problem. Oats, wheat, and other cereals also have this tendency, but to a much smaller degree, usually small enough to ignore. Sorghum-Sudan grass hybrid incorporated fresh in the soil hinders the growth of tomatoes, lettuce, and broccoli, but that’s a summer cover crop you won’t need to think about for several months.

I still haven’t got to my Conference notes on cover crop workshops, 2023-2024, but this is enough for one post!

Vegetable Growing Tips from Conferences, Winter 2023-2024. Part 1 CFSA

 

A Spacemaster cucumber plant in our hoophouse on April 23.
Photo Pam Dawling

I love learning new things and getting tips for improving our vegetable production. My events page tells you about recent and upcoming conferences. After I get home from conferences, I usually need to dive back into work, and am in danger of ignoring things I learned. Hence this blogpost. I’ll pass tips on, and extract the gems from my hand-written notes, making it more likely I’ll do something useful with them!

CFSA SAC 2023 banner

In November 2023 I took part in the Carolina Farm Stewardship Conference. I went to an engaging workshop called On-Farm Cover Crops Research in the Carolinas by Justin Duncan from NCAT/ATTRA, Jason Lindsay from the Southeastern African American Farmers’ Organic Network, and Steve McAllan, a last-minute substitute. I’ve got a blogpost brewing about native cover crops in vegetable production, so I’ll save the content for that post. Patrick Johnson also gave a presentation on native cover crops, which I’ll include more about in the promised post.

https://www.youtube.com/c/clem’sorganicgardens

I also participated in a workshop on Advanced Organic Weed Management for Vegetable Growers, given by Clem Swift of Clem’s Organic Gardens, from Pisgah Forest, NC, where they have 8 acres in field production of vegetables. I hadn’t realized the workshop was mostly machinery-focused, but I learned actionable tips anyway! I watched his video on potato planting, cultivation and harvest, which is similar to the way we grow potatoes. I learned a way of covering the edges of plastic mulch by walking backwards with one foot on the plastic to tension it, hoeing soil up onto the plastic. That sounds easier than our method using shovels, but sounds like it does require looser soil than we sometimes have where we use plastic. Clem has a well-organized system of first removing perennial weeds, then cultivating early and often to deal with annual weeds, including using a double-wheeled wheelhoe with a scuffle on either side of the row. Perhaps like one of these:

Double-wheeled double-scuffle wheelhoe. Hoss Tools
Double-wheel double-sweeps wheelhoe. Sweeps available as a conversion kit from Earth Tools.

Johnny’s Selected Seeds has a Wheelhoe Selection Guide in their Tool Library

Next I attended Precise Nutrient Management for Small-Scale Farms by Kyle Montgomery of Advancing Eco Agriculture. Kyle’s goal was to help us answer the question: How could marketable yields be significantly increased with minor changes to a fertility program? Plants have different nutrient requirements at different stages of growth. Sap analysis can show what the plant is taking out of the soil. In each 24 hour period, we want all soluble nitrogen to be converted to stable forms. This was something new for me to think about. I didn’t bring away anything specific to work on.

South Wind slicing cucumber.
Photo Common Wealth Seed Growers

High Tunnel Cucumber Production by Joe Rowland, CFSA’s Organic Initiatives Coordinator, covered preliminary findings from year one of CFSA’s SARE-funded organic high tunnel cucumber project. They trialed 6 varieties of cucumbers grown on 2 different trellis types (drop lines vs Hortanova netting) to compare disease occurrence and severity and marketable yield. Three participating farms replicated the trial to see what works best throughout the region.

Excelsior pickling cucumber. Photo Johnny’s Seeds

Their standout varieties were Itachi, an Asian white slicer (low yield but good disease resistance), and Excelsior pickler (highest yield).

Itachi white Asian slicing cucumber. Johnny’s Seeds

Poniente (a parthenocarpic European slicer) had the most disease of the 6 in the trial; Shintokiwa had the least disease, but was a slow producer, with low yields. The dropline system uses a single leader, more clips, more pruning and twirling than the Hortanova, where two “rows” could be made per bed, training two leaders from each plant in a V. This gave good airflow, slowed down the height-increase compared to single leader plants, and enabled herbs to be intercropped. We grow a succession of five or six plantings of cucumber, mostly outdoors, sprawled on the ground. Only for the early crop does it seem worthwhile to us to grow them in the hoophouse. But I’ve no idea how our yield compares with trained high    tunnel cukes, and perhaps measuring it would lead me to a different plan!

 Poniente cucumber. Territorial Seeds. Note trellis.
Shintokiwa cucumber High Mowing Seeds

Signs of winter, signs of spring

Tokyo bekana in our hoophouse in late December.
Photo Pam Dawling

 My  Winter-Kill Temperatures of Cold-Hardy Vegetables 2021 has not changed much in recent years. But I’ve just got some precise information on Tokyo bekana, the Asian green that grows well in summer as a lettuce substitute; grows very well outdoors in the fall; and grows wonderfully in the winter hoophouse even in low light conditions. In my 2023 list the outdoor killing temperature is listed as 25°F (–4°C).

Ugly, but not dead yet! Tokyo bekana outdoors on January 7, 2024 after several cold nights at 11°F (-11.5°C) at the end of November, and 12°F (-11°C) at the beginning of January.
Photo Pam Dawling

I harvested the last of the outdoor Tokyo bekana in November, except for one plant that was starting to bolt. I left that one to see when it would succumb to cold weather.  It was seriously damaged but not killed at 11°F (-11.5°C) at the end of November, and 12°F (-11°C) at the beginning of January. It was killed by 8°F (-13°C) and 10°F (-12°C) in mid-January.

Now it’s really dead! Tokyo bekana after two January nights at 8F and 10F.
Photo Pam Dawling

My tendency is to move only partway towards my new information each time I get some. This allows my info to gradually center in on the sweet spot, rather than have wild pendulum swings. So for the 2024 list, I’ll cautiously say it dies at 20°F (–7°C). I’ll release my new list for 2024 in March.

I’m updating my Phenology Record with Recommendations for Planting.

Our first crocus . February 1, 2024
Photo Pam Dawling

On February 1st we saw our first crocus bloom (it averages 2/7), our first speedwell, and Hellebore/Lenten roses with big buds (the flowers opened by 2/11). Hellebore often blooms with the daffodils, but our daffodils are only half-height leaves at this point. There are many hybrid hellebores and I’ve no idea which one ours is.

Lenten Rose (Hellebore) buds on February 1,2024.
Photo Pam Dawling

Robin Migration

Robins can be found year-round almost anywhere south of Canada, as residents or short-distance migrants. Birds that breed from Canada to the north slope of Alaska leave in fall for the U.S. Some robins winter as far south as the Southwest, Mexico, and the Gulf Coast.

Robin Range Map from All About Birds.

“Our” robins arrived on February 3rd, partying in an eastern redcedar (juniper) tree, enjoying the berries. According to this All About Birds Robin Range Map, robins are migratory thrushes that can be found here in Virginia year-round. Ours definitely migrate, arriving here anywhere from January 20 (2009) to March 3 (2013). The Virginia Department of Wildlife Resources notes that in mid-late February and early March they fly through headed north.

Eastern redcedar (Juniper) leaves and berries.

The DWR notes: “Robins’ seasonal movements are said to be tied to a 37-degree “isotherm.” An isotherm is a line on a map where the average temperature is the same at various points across the line.  As robins move from southern states into more northern ones, they stop and hunker down when they reach the limits of the isotherm.” They could reach the Arctic in May, if they travel that far!

Also see Journey North’s “Robin Migration Study” website. You can join and report your sightings and hearings of various signs of spring, not only robins.

Speedwell flowering on February 1, 2024.
Photo Pam Dawling

Cover Crops for February: Oats if you have a 6–10 week gap

Oats Cover Crop, Steve Groff farm, Holtwood PA. SARE Soil Health Resources

Cover Crops for February: Oats if you have a 610 week gap

In February, you’ll hopefully have made your crop plans and maps. Perhaps you’ve discovered some beds with no winter cover crop, that you are not using for early spring crops? Those winter annual weeds, chickweed, dead nettle and henbit, will shed lots of seeds if you let them.

If food crops were harvested too late to sow any winter cover crops, in early spring you will be looking at weeds, or “spontaneous vegetation” as I’ve heard them euphemistically called. The first year I gardened in Virginia I had lots of beds in April with purple flowers (henbit, purple dead nettle, some ground ivy) and I couldn’t think what to do – I didn’t need those beds for a few more weeks, so I wasn’t ready to till them. Oh, so wrong! I had squandered an opportunity to improve the soil as well as deal with weed seeds.

Now, when we have the crop plans made, we tag any beds that won’t be used for six weeks or more, till in the weeds and sow oats. In February or March here, with a last frost date of April 30, six weeks is just enough time here to make enough growth to out-compete the weeds and add to the organic matter in the soil.

Examples of crops in our gardens that occupy beds too late for us to sow winter cover crops include late cabbages, the last lettuce, leeks and fall Asian greens. Examples of late spring crops the next year include eggplants, peppers, tomatoes, edamame and chard. In some cases, we might even have no food crop planned until August or the beginning of September.

Six–ten weeks (depending on your climate) is long enough in early spring to get worthwhile growth from oats before prepping for the food crop.

Once we get to March 31 here, it is too late in the year for oats (they will quickly head up after making very little growth) and too soon to rely on frost-tender cover crops. See the section below on Stale Seedbed Technique.

Oats Cover Crops Steve Groff farm, Holtwood PA SARE Soil Health Resources

I wrote about oats as a winter-killed cover crop in August.

Will oats work as an early spring cover crop for you?

Large oat plants will be killed by three nights at 20°F ((–7°C) or by a single plummet to 6°F ((–14°C). Oats seedlings die at 17°F (–8°C). Consider your likely nighttime low temperatures during the period in question, and how likely your seedlings are to die. Oat cover crops of a medium size die around 10°F (–12°C). If they die after growing to adolescent size, no worries – just till them in before planting your next crop.

The minimum soil temperature for germination of oats is 38°F (3°C), and the time required to grow to a worthwhile height in cool weather is 6–10 weeks.

If you are in zone 8 or warmer, oats will not winter-kill, and can be grown in winter too – they may not reliably mow-kill, but are relatively easy to incorporate.

Oat plant and seeds. SARE

Pros and cons of oats as a cover crop

Like most cover crops, oats add biomass and nutrients, increase the biological activity of the soil, smother weeds, reduce soil erosion (their fibrous roots anchor the soil) and absorb and store rainfall. Oats are easy to establish, are fast-growing and particularly good at shading out germinating weed seeds and at salvaging any nutrients (especially nitrogen) left from the previous crop and making them available to the following crop.

In early spring you won’t get as much biomass as from a fall oat cover crop, when you can get. as much as 2000–4000lbs per acre (2240–4480 kg/ha. Certainly not enough to be a no-till cover crop for your next food crop. Oats provide some allelopathic effect (producing biochemicals which inhibit the growth of other plants) although less than winter rye. Like most plants, oats form arbuscular mycorrhizal associations (fungi penetrate the plant’s cell walls and help capture nutrients from the soil) – a mutually beneficial relationship, although probably not a big feature when conditions are cold.

Oats are not as good as some other cover crops at breaking up compacted subsoil, although they do loosen the upper layers of topsoil nicely. (Just where you are going to sow.) Oats do not add nitrogen, and unlike flowering cover crops, they do not attract beneficial insects (assuming they are turned under or mowed before heading up and shedding pollen).

Common Oats. Buy Organic and avoid GMO canola seed inclusions

Buying oats, sowing rates

We used to buy “horse oats” (feed oats) locally and not worry about organically certified seed. But I noticed canola sprouting along with the oats, and I don’t want GMO canola going feral in our gardens! We plan ahead and order extra Organic spring oats in summer when making our big cover crop seed order.

Oats will grow in soils with a pH range of 4.5–7.5, and even do OK in soils without great fertility. They have some tolerance to flooding, but not much to heat or drought (although more than rye).

The sowing rate for drilled oats alone is 80–100lbs/ac (90–123 kg/ha). The broadcast rate is 110–140lbs/ac (123–155kg/ha). On a small scale, this is 4–6 oz/100 sq ft (12–20gm/sq m). Aim to cover the seed to a depth of about 1″ (2.5 cm).

Oats grow to a height of 2–4 feet (0.6–1.2 m) if not killed before then.

Stale seedbed technique and tarping

If you have less than 8 weeks until you need to plant the food crop, you are better off mowing when you can, or weed whipping, to prevent weeds seeding.

Tarping beds to kill weeds.
Photo Cornell Small Farms Unit

You could mow and tarp. I don’t yet have much experience of tarping, but there are good directions in The Lean Micro-Farm and The Market Gardener. There are also online videos. The basic idea is to mow the bed, cover it with a black plastic silage tarp, weight down the edges to get good soil contact and stop the tarp blowing away, and wait till the plant matter has disintegrated, or until you need to use the bed. This will take several weeks in cold weather, (although only a few weeks in summer). If you have a late-finishing fall crop, you could mow and tarp as soon as the crop is finished, and leave the bed tarped until spring. Weeds germinate under the tarp, but then die without light.

For a stale seedbed technique without tarps, you could mow, till several weeks before planting, water (if it doesn’t rain) to germinate weeds, and hoe off those weeds once a week. This can really help reduce the weed seedbank in the soil. It is particularly useful before sowing small seeds of slow-growing crops, such as carrots.

What not to sow in short gaps in early spring

Other quick cover crops, like buckwheat and soybeans, are not at all frost-hardy, so wait until after your last frost date to sow those.

In early spring, the air and the soil are cold, and sowing a fast-growing vegetable crop will not be successful with a gap of less than eight weeks. Crops take too long to grow at this time of year.

 Spring gaps longer than eight weeks

If you have more than eight weeks you could try those fast-growing vegetables: kale, spinach, Tokyo bekana, radishes, chard, lots of salad crops, senposai, mizuna, tatsoi, land cress. Or try Eat-All Greens, an idea from Carol Deppe. Patches of carefully chosen cooking greens are sown in a small patch. When it reaches 12″ (30 cm) tall, Carol cuts the top 9″ (23 cm) off for cooking, leaving the tough-stemmed lower part, perhaps for a second cut, or to return to the soil.

Young spinach seedlings.
Photo Pam Dawling

Undersowing oats in spring

Another way we have used oats in spring is between rows of peas (grown on the flat, not in beds). We sowed the oats the same day as the peas, and lightly tilled the oats in. We mowed the oats as needed during the pea training and harvest period to make access easy. This reduced the number of weeds, and we quite liked the “lawn” underfoot!

Green fallow (Full year cover crops)

If you have a bed with no crop planned for the whole season, you could grow a Green Fallow. You can plant long-term cover crops to replenish the soil. Start with oats or one of the more cold-hardy grasses, and once we get to warm weather, after the frosts, till that in (or mow if it mow-kills) and sow warm weather cover crops.

Reasons not to do no-till food crops in spring

Untilled soil in spring is colder than tilled soil, and growth of anything you plant in it will be slower, and harvests delayed. You could consider broccoli or cabbage, perhaps, but not warmth-loving crops. You may get more slugs and/or more fungal diseases with no-till. The cover crop could try to regrow, or you could get some weeds anyway.

Also, if you are planting by hand, transplanting into untilled soil is harder work than planting into loose tilled soil. Hand-sowing into untilled soil is tricky – winter snow and ice can leave quite compacted soil. If the notion of organic no-till appeals to you, experiment on a small-scale the first year. Reduced tillage is another option. Till out narrow strips in the oats for your plantings of large food crops normally grown on a wide row-spacing.

Using a push seeder for cover crops

EarthWay push seeder.
Photo from EarthWay

You can drill cover crop seeds using a push seeder. See VABF Using Manually-Operated Seeders for Precision Cover Crop Plantings on the Small Farm. Don’t worry if the seed ends up deeper than ideal. It will still germinate.

 

Cover Crop Planning

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 or download it as a free PDF from SARE.

Success with Growing Cabbage in Spring

Young Early Jersey Wakefield cabbage, a fast maturing pointed variety.
Photo Pam Dawling

Some of this material is from my book Sustainable Market Farming.

Cabbages can be reliable workhorses, providing large harvests over long periods. In colder regions, cabbages are planted only in the spring and grow all summer, into the fall and winter, until cold weather kills them. In the South, they are a spring/early summer and a fall/overwintered crop, as it’s too hot to grow them in the summer. In parts of California and the Pacific Northwest, they’ll grow year-round.

Cabbage crop requirements

Cabbages do best on fertile, well-drained soil with adequate moisture. They require a lot of potassium, so a sprinkling of wood ash, kelp meal or granite dust could be helpful. Calcium, boron, iron, manganese and molybdenum are also important for good brassica crops — healthy, biologically active soils can usually supply enough of all these. If not, amend as needed.

Young Farao cabbage, a good fast-growing round variety.
Photo Pam Dawling

Cabbage varieties

Be clear about what kind of cabbage you are looking for, especially whether it’s for fresh eating, slaw, sauerkraut or storage, and what size you want and how many days from seeding to harvest.

  • For quick-maturing cabbage, we choose Early Jersey Wakefield (63d OP), Golden Acre (62d OP) and Farao (64d F1) (All days to maturity in this list are from transplanting in spring. Add 14 days for direct sowing. Subtract 10-14 days for warm weather sowings.)
  • For large solid cabbage for making sauerkraut, we choose Gunma (110d F1), Tribute (103d F1) or Early Flat Dutch (85d OP)
  • For a green cabbage that holds well in hot weather, to extend the season as long as possible, the flat Tendersweet (71d F1) is tasty and works well for us. It is good for coleslaw and wraps, but not for storage
  • We like a red that’s fairly large and yet quick-maturing (many reds are too slow for us, taking us deep into hot weather). We used to favor Super Red 80 (73d), but gave it up after two poor years. Ruby Perfection (85d F1) stores fairly well, as does Integro (85d F1)
  • We like savoy cabbage, and find Melissa (85d F1) and Famosa (80d F1) quick and reliable
  • For storage we have liked Storage #4 (95d F1), Kaitlyn (94d F1), and Late Flat Dutch (100d OP)
  • Deadon (105d F1) is a particularly cold-hardy one to grow into the winter. It survives down to at least 10°F (-12°C)
  • High Mowing and Johnny’s Seeds have good selections of over twenty cabbage varieties, including the 77d 10-17 lb (4.5-7.7 k) Megaton, good for fresh eating and kraut.

Sowing cabbage seed

A seed flat of cabbage and several flats of spotted out seedlings in our greenhouse in February.
Photo Pam Dawling

In early spring, transplants have the advantage over direct-seeded crops — they grow faster under protected conditions and bring earlier harvests. At other times of year, you may prefer to direct seed.

Work back from your desired harvest date to calculate the sowing date. Naturally you’ll need to allow for your climate and choose a realistic transplanting date. We start our very first cabbages in our greenhouse in mid–late January, as soon as I’m mentally prepared to start a whole new year. Maincrop cabbage follows in mid-February.

Despite being a cool-weather crop, brassicas actually germinate very well at high temperatures: the ideal is 77°F–85°F (25°C–30°C), and 95°F (35°C) is still OK. Given enough water, the seedlings will emerge in four and a half days at the low end of this range, and at the top in only three days. The minimum temperature for good germination is 40°F (4.5°C), but you’ll need to wait more than two weeks for emergence if it’s that chilly.

We start our spring cabbages in home-made open wood flats, sowing 3–4 seeds per inch (5–10 mm apart). We press a plastic ruler 0.25″ (6 mm) deep into the seed compost to make a small furrow, spacing the rows 2″–3″ (5 cm) apart.

Once they have emerged, the seedlings need good light, nutrients, airflow and protection from bugs. 60°F–70°F (15°C–21°C) is a good temperature range for growing them. As soon as the seed leaves are fully open, we spot (prick) them out to 4″ (10 cm) deep flats, with 40 plants per 12″ x 24″ (30 x 60 cm) flat. The plants grow to transplanting size in these flats.

Spotting cabbage seedlings from a seed flat into a transplant flat.
Photo Wren Vile

For the last two weeks before transplanting, harden off the plants by moving them into cooler, breezier, brighter conditions.

Transplanting cabbage

We grow spring cabbage in 4′ (1.2 m) beds, at two rows per bed, with plants 18″ (50 cm) apart. Mini-cabbages can be spaced at 8″–12″ (20–30 cm) in the row, with rows 12″–18″ (30–45 cm) apart, and may give higher total yields as well as heads of a more useful size.

We aim to transplant at four true leaves (5–8 weeks after sowing in spring). This is early to mid-March for the earliest cabbage (seven weeks old), very early April for maincrop cabbage. Soil temperatures of 65°F–75°F (18°C–24°C) are ideal. Optimal air temperatures for most brassicas are 60°F–65°F (15°C–18°C).

Water the seedlings well before transplanting, and plant all the way up to the base of the first true leaves to give the stem good support. Press the soil very firmly around the plants so the roots have good soil contact and won’t die in an air pocket. I was taught to tug on a leaf after transplanting: if well planted the leaf will tear and the plant will remain in the ground. Water within half an hour of planting and again on the third and seventh days, and then once a week.

Young spring cabbage with a hay mulch. Wren VIle

For cabbage, the sixth and seventh leaf stage is the most vulnerable. If the weather deteriorates at this critical time, give your plants extra protection. High daytime temperatures can to some extent compensate for low nighttime temperatures — it’s cold days and cold nights together that do the damage. We use thick rowcover over our spring cabbages for a few weeks after transplanting, then may switch to insect netting.

Two weeks after transplanting, we check the plants and fill the gaps with transplants we have kept for this. If it is necessary to use big plants to fill gaps, we pinch off a few of the lower leaves to reduce their water needs.

Caring for  cabbage in spring and summer

About a month after transplanting maincrop cabbage (mid-May), we remove the rowcovers and the sticks we use to hold them down.

We use only overhead sprinkler irrigation (not drip tape) for spring cabbage, which helps cool the leaves and can wash off aphids. Organic mulches help keep the soil cool, as well as adding lots of organic matter to the soil. Brassica roots are relatively shallow, so long droughty spells without irrigation can cause problems. One inch (2.5 cm) of water per week is about right.

One of our impact sprinkler tripods, in a broccoli and cabbage patch.
Photo Pam Dawling

Cabbage pest control

Using rowcovers or insect netting keeps many pests off the plants while they are small. We have not had much trouble with aphids, perhaps partly because of our overhead sprinklers; insecticidal soap sprayed three times, once every five days, can usually deal with them. Our worst pest is the harlequin bug. When necessary, we handpick them. Ladybugs are reputed to eat harlequin bug eggs.

Sometimes we have had enough cabbage worms to make Bt (Bacillus thuringiensis) necessary, but usually paper wasps eat the caterpillars. The action threshold is an average of 1 cabbage looper, 1.5 imported cabbageworms, 3.3 armyworms or 5 diamondback moth larvae per 10 plants. Below this level you can do watchful waiting rather than spraying with Bt or spinosad. Apparently paper or plastic fake cabbage moths on sticks will deter more from moving in. There are templates for homemade cabbage moth decoys online. The eyespots are important!

Yarrow flowering in our hoophouse in late November, 13 months after sowing.
Photo Pam Dawling

We are also lucky enough to have the naturally occurring wasp parasite of cabbage worms, the Braconid wasp Cotesia species, which are found as small cottony white or yellowish oval cocoons in groups on brassica leaves. The Cotesia wasps like umbelliferous flowers, and overwinter on yarrow as well as brassicas. If you find Cotesia cocoons and your brassicas aren’t diseased, you can leave plants in the field over winter. Or you could collect up leaves with cocoons in late fall and store them at 32°F–34°F (0°C–1°C) until spring. Hopefully no one will clean out your fridge without asking.

To float out worms and aphids after harvest, soak the produce in warm water with a little vinegar for up to fifteen minutes, then rinse.

Harvesting cabbage

Our cabbage heads up from May 25 and some hold till July 15. For storage cabbage (a valuable crop in summers in warm climates with scarce fresh leafy greens), we set the cut heads upside down on the stump, in the “basket” of outer leaves, and come back an hour later to gather them into net bags. This allows the cut stem to dry out and seal over, improving storability.

Mature Farao early cabbage. Note the curling-back leaf on the head, a sign of maturity.
Photo Pam Dawling

Favorite posts of 2023: soil, winter, garlic, melons, beans, aphids

I’m hunkered down on this rainy January day, in expectation of high winds and lots of rain. I’ve battened down the hoophouse and I’m working to get a blog post out before the electric coop’s warning of possible extended power outages comes true!

One of many wheelbarrows full of compost we spread on our raised beds every year.
Photo Wren Vile

In the past year, my top post has been Soil Tests and High Phosphorus Levels. Clearly a worrying topic for those who like me, once though compost should be applied as generously as possible. I wrote this post in 2017, and it’s still an issue many people want to learn about.

The second highest number of views goes to Which Vegetables are Genetically Modified (GMOs)? Another worrying topic.

Ugly, but not dead yet! Tokyo bekana outdoors on January 7, 2024 after several cold nights, at least two at 20F, two at 18F, one each at 15F and 12F. Photo Pam Dawling

In third place  is Winter-Kill Temperatures of Cold-Hardy Vegetables 2021, and in fourth place is Winter-Kill Temperatures of Winter-Hardy Vegetables 2016. The 2018 version is in 8th place. My highest number of views in a single day came when Texas had that awful very cold weather, in mid-February 2021, and farmers and gardeners needed to find out in a hurry which crops to try to protect, which to give up on, and which needed no attention.

Fifth place goes to one of my many garlic posts: Garlic Scapes! Three weeks to bulb harvest. Scapes, the flower stems of hard-neck garlic, are an underappreciated auxiliary crop. They are not just a freebie extra, but removing them helps the garlic bulbs grow bigger. Pulling scapes would be worthwhile even if you didn’t use them.

Pulling garlic scapes.
Photo Wren Vile

Cover Crops in Summer is number 6 in popularity. Sunn hemp is joining our list of favorites, along with buckwheat and soy.

Root Cellar Potato Storage comes in at number 7. That’s from 2018. Root cellars haven’t changed!

Crates of potatoes in our root cellar.
Photo Nina Gentle

Harvesting Melons is next. I remember when I didn’t know what “full slip” meant. I found out and decided to make a post, reckoning many other people didn’t know either. That’s a heritage post! From 2012, the year I started this site.

Young bush bean plants.
Photo Pam Dawling

Green Beans All Summer is close behind. The post includes an unusual method of planting bean seed through plastic mulch, as well as early season and late season beans, and scheduling sowings for continuous harvests all summer.

Growing Flowers to Attract Aphid Predators rounds out the list. The post includes info and photos of many annual flowers we tried for our hoophouse. Most of them did not flower early enough to deal with the January and February aphids that have no ladybugs to eat them. We have established several perennial yarrow plants, and have hopes for those this year. We’ve also come to appreciate the value of bolted brassicas, such as tatsoi, turnips, and senposai. Their flowers do attract beneficials.

Leave a comment if your favorite didn’t make the top ten, or if there is a topic you’d like me to cover, or update, or give more details on.

Vegetable Seed Varieties for 2024

 

Preparing to sow Rainbow Chard in 2018.
Photo Pam Dawling

Vegetable Seed Varieties for 2024

Have you ordered your seeds for next year yet? The earlier you order, the best chance you have of getting the varieties you want. Later, some will sell out. It’s true that when you order very early, some seeds won’t be available yet. The seed growers are still drying and cleaning them, weighing them and running them through germination testing. Your patience will be rewarded with high quality seeds.

I love looking through catalogs to find new exciting-sounding varieties! After so many years of gardening, I’ve tried lots of different kinds, and have definitely grown attached to some reliable favorites. I recommend planting a small amount of a variety new to you that sounds good, alongside your usual well-loved variety. And what do I mean by “sounds good”?

In 2014 I wrote Reading Between the Lines in the Seed Catalogs to share what I’d learned about decoding catalog-speak, and not getting distracted by wondrous claims, failing to notice the catalog never even claimed it had good flavor. Or high yields. Or good disease-resistance. That post lists 15 features to look for.

We look for flavor, productivity, disease-resistance, an appropriate fit with our climate or latitude, general adaptability, varieties that don’t require erecting elaborate trellises, ones that don’t sprawl too widely, ones that don’t take a really long time to reach maturity.

If we’ve had a few years of poor performance from a crop, we’ll try several new varieties. We have done trials of heat-tolerant eggplants, winter spinach for the hoophouse and outdoors, storage cabbage, and now we need to start over with broccoli.

Green Magic broccoli Credit Johnnys Seeds

For many years we grew three varieties of hybrid broccoli with different number of days to maturity. That enabled us to sow them all on the same day, transplant them all on the same day (or in the same week), and get an extended harvest period. Some of our favorites dropped out of the market, we floundered with various kinds, including some Open Pollinated varieties that sounded good. This year I am advocating for Green Magic (57d F1, 6-8″ main head and sideshoots too); Belstar (65d F1, also 6-8″ main head, plus sideshoots); and Marathon (68d F1) or Fiesta (70d F1, 6-7″ head, few sideshoots, short harvest window). Marathon has done well for us in the past. In my experience, broccoli is a crop where hybrids are much more productive than OP types.

Green Machine zucchini. Photo Johnny’s Selected Seeds

Our much-loved Tendergrey zucchini, one of the flecked pale green types, isn’t easily available this year. But Green Machine (45d F1) sounds very good! Open plant habit is a phrase I like. Moderate spines is one I don’t like, but we have some pull-on plastic sleeves to deal with irritating plants. Widely adapted, excellent disease package, and high yields all appeal to me.

We rely on Provider (50d OP) and Bush Blue Lake snap beans every year, with a short row of Strike in the hoophouse a month earlier than outdoors. We found we need an upright variety to get nice beans undercover, as the bean plants grow sprawlier than they do outside, and we don’t want to be treading on them.

Washing Cylindra beets for storage.
Photo Wren Vile

We rely on Cylindra or Formanova (54d OP) beets, long-shaped tender ones that grow up out of the ground, are tender and easy to peel after cooking. Seems like the yield must be high when half the root is above ground, and half below!

Premium Late Dutch cabbage (100d OP) has done well for us. Johnny’s has a lovely-sounding storage cabbage, Promise (96d F1). 6 ½ lbs at 18″ spacing, 9-10 lbs at 24″ spacing. And two attractive purplish Chinese cabbages Red Trumpet (60d F1), a tall Michihili type, and Merlot (60d F1), said to be an improved Red Dragon Napa type. I hadn’t got round to trying Red Dragon yet, so I can’t speak to its shortcomings. Merlot admits to being more prone to tipburn than green varieties and to be somewhat susceptible to bolting. Some trials on a small-scale are called for!

Merlot purple Chinese cabbage.
Photo Johnny’s Selected Seeds

Carrots – oh why so many yellow, purple, red and black ones? None in my experience match the succulence and growth rate of orange Danvers 126.

Collards – for years I have loved Morris Heading, but the recent explosion of options brought us by the Heirloom Collard Project is leading us to try others. Some have remarkable colors, combined with high yields.

The delicious early Bodacious sweet corn is harder to find. Thanks Southern Exposure for carrying it. Our reliable favorite Kandy Korn has become hard to find.

Our favorite slicing cucumber has been renamed by Fedco as Generally, a name we’ve been using for years. This year we also tried South Wind from Common Wealth Seed Growers and were quite taken with its sweetness.

South Wind slicing cucumber.
Photo Common Wealth Seed Growers

As always, there are new frilly mustards for baby greens and salad mixes. We like Mizuna, Golden Frills, Scarlet Frills and especially Ruby Streaks. I feel drawn towards purple stemmed Ember and dark red Miz America.

For leeks, we grow King Richard and Lincoln for fall and Tadorna for overwintering in our Zone 7a climate. No complaints there. all are very good for their purpose.

I’m always on the lookout for new lettuces. This summer we tried Albachiara from High Mowing, and it did very well. We’ll get more for this coming year. It’s a Batavian heat-tolerant type. Now our climate is changing, we need to grow Batavians for more weeks of heat. Finding a new one is great! Dark red Cherokee has been my favorite.

I shouldn’t even look at the spring lettuce selection, or I’ll order more than we can use in the short spring season we have. Most spring varieties can be grown in the fall here too, but we like to switch to cold-tolerant ones.

Ezrilla, a favourite cold-hardy lettuce.
Photo Wren Vile

This winter we are growing the beautiful Rhone in our hoophouse bed of cut-and-come again leaf varieties, along with Ezrilla, Hampton, Brentwood, Tango, Revolution, Oscarde and Panisse.

For scallions we like Evergreen Hardy White (65d OP) every time, and feel no need to try another.

We have been growing Sugar Ann early dwarf snap peas in our hoophouse (sown Feb 1), but next year we are trying Oregon Giant snow peas instead. We think snap peas are best raw, and used to cut them into our salad mixes. But over the past few years, by the time the snap peas are ready to harvest, our winter salad mix days are coming to a close, and our outdoor lettuce head harvest is starting. We don’t grow enough snap peas to serve them on their own in big bowlfuls. We think we’ll be able to pick enough snow peas for stirfry mixes instead! In March we sow Sugar Ann outdoors and get plenty.

For sweet peppers our keywords are prolific, thick-walled, tasty, and 90 days or less from transplant to ripe harvest (76d to green). We like fairly large peppers too, and avoid small pointy ones that could get confused with hot peppers in the fridge.

Tomatoes are a whole topic on their own. We love Sun Gold and Black Cherry, Mountain Magic and Garden Peach. Others come and go. Next year we are trying Damsel  (73d F1). Damsel is in the new tomato category called “Hylooms” – hybrids resembling heirlooms in color and flavor, with added disease resistance.

Damsel (71d F1) Hyloom tomato.
Photo High Mowing Seeds

Planting Garlic and Garlic Scallions

 

Garlic scallions ready for harvest in early spring.
Photo Wren Vile

I have often written about garlic, and here I am going to focus on planting garlic. But before that, I want to encourage you to make the most of the opportunity to also plant a bonus crop: garlic scallions.

  • Garlic scallions are very little work,
  • They come with no extra cost,
  • They provide a very tasty and visually attractive crop.
  • They will be ready to harvest in the Hungry Gap, the early spring period before any new crops are ready to harvest, when our palates are tiring of stored roots and hardy leafy greens.
  • You may have run out of garlic bulbs and be craving that strong flavor to brighten your meals.
  • Ours are ready to harvest from March 10 until we run out or they are visibly bulbing up (April 30?).
  • If you are selling crops, garlic scallions can bring a big return for a small bunch, because most people will be happy with 3-6 garlic scallions.
  • Both garlic scallions and Garlic Scapes can extend your garlic sales season.
Garlic scallions prepared for sale. Typepad.com

The easiest time to plant garlic scallions is right after your main planting for garlic bulbs, in the fall. In preparation for planting your garlic cloves for bulbs, break apart the bulbs and sort the cloves. You won’t grow large bulbs of garlic from tiny cloves, so you’ll want to separate out the good ones for bulbs. Put the tiny cull cloves in small buckets and save them to grow garlic scallions. Much more productive than throwing them on the compost pile!

You can also plant for garlic scallions at other times of year. I don’t know what the limits are. You can certainly plant in a hoophouse later in the fall than you could plant outdoors. You can certainly plant softneck varieties outdoors for scallions in January (weather permitting) or February.

Some growers are finding they can get a better income from garlic scallions than from bulb garlic, and so they are working to extend the garlic scallion season.

As an alternative to planting small cloves, you can plant whole cull bulbs, and turn a misfortune into a windfall. I don’t mean bulbs with fungal infections, but bulbs that ended up too small to sell, or use at home. Plant the small bulbs at a wider spacing than tiny cloves, maybe 5″-6″ (12-15 cm) apart. You’ll grow ready-made bunches of garlic scallions!

Garlic scallions in February. Photo Pam Dawling

Planting Garlic Scallions

  • We plant small cloves for garlic scallions in early November immediately after planting our maincrop garlic.
  • We choose a small space that is easily accessible in late winter and early spring, where we often walk by.
  • We make 3″ (7.5 cm) deep furrows with a hoe, only about 2″ (5 cm) apart. A lot fits in a small space.
  • We tumble the small cloves into the furrows, any way up, shoulder to shoulder.
  • We close the furrows, tamp down the soil, and cover with a mulch of spoiled hay. Tree leaves or straw would also work.
  • Some growers have experimented with replanting small whole cull bulbs. This could be a good way to salvage value from a poorly-sized garlic harvest.
  • Softneck garlic varieties can make worthwhile growth for scallions even if planted January-March. By planting later than this, it is possible to stretch the harvest period out later.
  • Some growers find they can get a better income from garlic scallions than from bulb garlic.
Garlic scallions ready to harvest outdoors in late March. Think what might work in a hoophouse! Photo Pam Dawling

Harvesting Garlic Scallions

We harvest garlic scallions from early March until May. 3/10 to 5/15 or later in central Virginia

  • Once the plants are 7″–8″ (18–20 cm) tall
  • We simply loosen the plants with a digging fork (rather than just pulling) and lift the whole plants out of the ground.
  • We trim the roots, rinse, bundle, and set them in a small bucket with a little water.
  • Scallions can be sold in bunches of three to six depending on their size.
  • Some people cut the greens at 10″ (25 cm) tall and bunch them, allowing cuts to be made every two or three weeks.
  • We tried this, but prefer to harvest whole plants.
  • We grow a lot of bulb garlic and have a lot of tiny cloves available, hence a lot of garlic scallion plants.
  • Our springs are short and don’t really provide opportunity to make multiple harvests.
  • The leaves keep in better condition if still attached to the clove.
  • If you do have more than you can use fresh, they can be chopped and dried, or frozen for making pesto later in the year.
Harvesting garlic scapes in May
Photo by Wren Vile

Other Posts About Garlic

Everything You Need to Know About Garlic posted in June 2020 includes many, many links on all stages of garlic growing. And to sum it all up see My Garlic Slideshow

See Garlic Almanac and Phenotypic Plasticity posted in May 2021. It includes many links for those deciding which kinds of garlic to grow

Much about garlic is to be found in my Alliums for the Month Series from 2018-2019. The April 2019 post gives links to each of them.

Planting garlic in November. Photo Brittany Lewis

Planting Garlic

  • Both hardneck and softneck garlic do best planted in the fall, though softneck garlic may also be planted in the very early spring if you have to (with reduced yields).
  • Plant when the soil temperature at 4″ (10 cm) deep is 50°F (10°C) at 9 am. If the fall is unusually warm, wait a week.
  • Cloves for planting should be from large (but not giant) bulbs and be in good condition. Bulbs should be separated into cloves 0–7 days before planting.
  • Planting deeper helps keep the garlic at a steadier temperature (milder during the winter, cooler once spring heats up)
  • When properly planted and mulched, garlic can withstand winter lows of -30°F (-35°C).
  • Garlic roots grow whenever the ground is not frozen, and the tops grow whenever the temperature is above 40°F (4.5°C).
  • If you miss the window for fall planting, ensure that your seed garlic gets 40 days at or below 40°F (4.5°C) in storage before spring planting, or the bulbs will not divide into separate cloves.
  • Plant garlic in cold areas with the goal of getting a good amount of root growth before winter has a firm grip, but not to make top growth until after the worst of the weather.
  • In warm areas, zones 7 and warmer, the goal is to get enough top growth in fall to get off to a roaring start in the spring, but not so much that the leaves cannot endure the winter.
  • If garlic gets frozen back to the ground in the winter, it can regrow and be fine. If it dies back twice in the winter, the yield will be lower than it might have been if you had been luckier with the weather.
Grey Duck Garlic logo
  • Grey Duck Garlic has a helpful chart by USDA winter-hardiness zone. I’ve combined their information with that I gathered previously.
  • In zones 0-3, if no permafrost, plant garlic in September.
  • In zones 3b-5, plant late-September to early-October. Plant 2-3 weeks after the first frost but before the ground freezes solid for the winter. Another way of counting is 6 weeks before the ground freezes.
  • In zones 5-7, plant in the second half of October. If your area does not normally get seasonally frozen ground, you could plant later.
  • In zones 7-9, plant in early-mid November; up till late November in zone 9.
  • In zones 9 and 10, look for soil to be less than 85°F (29°C) at 2″ (5 cm) deep – garlic can be planted in December or even as late as February if you have vernalized the planting stock. (Vernalization for hardneck garlic = 6 weeks of cold temperature below 40-45°F/4-7°C; softneck is less demanding) Without sufficient vernalization, the bulbs will not differentiate (divide into separate cloves).
  • In zones 11-13, I think plant in January or February after vernalization – check with local growers or your Extension Service, as there’s very little info out there. Also see the section below on growing garlic in the tropics. See Grey Duck Farm’s Southern Garlic Grower’s Guide by Susan Fluegel
  • If planted too early, too much tender top growth happens before winter.
  • If planted too late, there will be inadequate root growth before the winter, and a lower survival rate as well as smaller bulbs.
Garlic beds next to rowcovered broccoli beds, under a stormy sky.
Photo Wren Vile

Garlic Growth Stages

Garlic and onions are biennial crops grown as annuals. They have 3 distinct phases of growth: vegetative, bulbing and blooming (bolting) The switch from one phase to the next is triggered by environmental factors. It is important to understand that it does not work to plant onions or garlic at a random date in the year.

  1. Vegetative growth (roots and leaves). For large bulbs it is important to produce large healthy plants before the vegetative stage gives way to the bulbing stage. If planted in spring, garlic plants will be small when bulbing starts, and only small bulbs are possible.
  2. Bulbing is initiated when the daylight reaches the critical number of hours. Garlic bulb initiation (and the end of leaf growth) is triggered by daylight increasing above 13 hours in length (April 10 here at 38°N). Soil temperatures over 60°F (15.5°C) and air temperatures above 68°F (20°C) are secondary triggers. The rate of bulbing is more rapid with high light intensity and increased temperature.
  3. Flowering (Garlic scapes): Scapes are the hard central flower stems of hardneck garlic. Removing the scapes can increase the bulb size 25%, and also provides an additional food crop. In general, plant flowering is triggered by some combination of enough vernalization (chilling hours – maybe 10 weeks below 40°F/4.5°C), plant maturity, daylength and temperature. In cold weather the plants suppress the flowering signal. When the daylength and the temperature are both right, they trigger flowering.
Additional Stages:

Fattening up: Garlic can double in size in its last month of growth.

Drying down: Hot weather above 91°F (33°C) ends bulb growth and starts the drying down process.

Popping garlic for replanting at Twin Oaks.
Photo Bell Oaks

Cover Crops for November: Winter Rye and Austrian Winter Peas

Cover Crops for November: Winter Rye (with Austrian Winter Peas early in November)

Winter rye headed up. Mow or turn it under very soon! Don’t let it shed seed.
Photo Pam Dawling

The first half of November is the last chance to sow winter cover crops in central Virginia

Our average first frost is October 14-20. If yours is later, see my post Cover Crops for October. It is still worthwhile to sow a few cover crops up to three weeks past your average first frost, and I’ll tell you about those, with ideas on what to do if your climate is past that point.

If the area is ready for cover crops up to 10 days past the frost date, sow winter wheat or winter rye and hairy vetch or Austrian winter peas.

See Planning Winter Cover Crops, a post that includes my Short Simple Guide to Winter Cover Crops and my slideshow Cover Crops for Vegetable Growers.

Last Chance Cover Crops in November: Rye

Rye grows impressive roots that improve the soil. Kauffman Seeds

Winter rye can still be sown in the mid-Atlantic in the first half of November. Winter rye is the cereal grain rye, not ryegrass. Ryegrass comes in annual and perennial forms, but neither is a good winter cover crop here. They don’t produce as much biomass as cereal rye, and can become weeds in our climate.

Winter rye is hardier than any other cover crop and can take later planting dates. Some people do sow winter wheat in early November rather than winter rye, so if you don’t have rye seed, use wheat. It can be tricky to have the cover crop seed you want, without risking buying more than you need. Sometimes it pays to use what you already have, as it may not give good germination if saved over to next fall.

Winter rye has an allelopathic effect (inhibition of germination) on small seeds, that lasts three weeks or more after rye is turned under. This means you will need to be fairly confident that the weather will allow you to till the rye in with three weeks to go before sowing carrots, spinach or other spring crops with small seeds. Transplants are not affected in the same way. If necessary, reconfigure your crop rotation plan over the winter. Plan for the next food crops after winter rye to be ones planted after late April, such as late corn plantings, winter squash, transplanted watermelon, sweet potatoes, tomatoes, peppers, June-planted potatoes, fall brassicas, and second plantings of summer squash, cucumbers, beans.

A field of winter rye with a strip of crimson clover in early May.
Photo Bridget Aleshire

Other key features of winter rye cover crop

  • Rye grows 5′-7′ (1.5-2.1 m) tall.
  • Mow-kills at flowering, but not earlier.
  • Suppresses weeds (especially lambsquarters, redroot pigweed, ragweed).
  • Adds lots of organic matter if grown to full size.
  • Improves the soil’s ability to absorb and store water.
  • The roots hold the soil together and greatly reduce erosion.
  • Can be used to scavenge nutrients left over from a previous legume crop or to hold onto nutrients applied for a crop that failed.
  • Sow from 14 days before to 28 days after first fall frost.
  • Don’t sow before September in zone 7 – it may set seed.
  • Rye makes little growth in mid-winter, but very good growth once spring arrives.
  • Rye can be sown in the spring, although when incorporated, oats break down quicker.
  • Can be undersown in sweet corn or in fall brassicas in early September, and left as a winter cover crop.
Cover crop of rye and winter peas with flowering crimson clover. Photo Bridget Aleshire.

Include Austrian Winter Peas if possible in the first week of November

See my September post for more about the benefits of including legumes with winter cover crops grasses. Also how to inoculate legume seeds with the nitrogen-fixing bacteria. Austrian winter peas can be sown later than other legumes. See my October post for more about those. See Working with the time you have left for options if you are in another climate zone.

A key to success with legumes is to sow early enough in fall to establish before winter halts growth, and to plan not to need that plot next year until flowering time for that legume. Austrian winter peas bloom here at the end of April (about a week later than crimson clover, and a week earlier than hairy vetch). (If you have a legume that doesn’t reach flowering, you get less nitrogen for your money, and will need to add some compost or other source for the following food crop.) Suitable crops for following Austrian winter peas are ones planted after May 1: winter squash, melons, sweet potatoes, tomatoes, peppers, middle sowings of sweet corn, June-planted potatoes. This is pretty much the same list as crops that can be planted after winter rye.

Austrian winter peas
Photo https://www.uaex.edu

October 15 (our average frost date) is our clover/peas watershed (legume-shed?). Before that date we use crimson clover; after it (until 11/8, 3 weeks after our average frost date) we sow Austrian Winter Peas, along with winter rye or winter wheat.

Austrian winter peas winter-kill in zone 6, but are hardy in zone 7. Hardy to 0°F (-18°C). Sow Austrian winter peas at least 35 days before first hard freeze (25°F/-4°C) – in zone 7, that’s a 50% chance on 11/8. See Weatherspark.com for info on your location, or Dave’s Garden.

Last Chance cover crop

In the second week of November, we sow winter rye alone as our last chance cover crop. It is too late for any legumes.

Grain seed will store OK for the next year, but peas and beans really lose viability fast. If you still have Austrian winter pea seed from last year, I’d say throw it in this November rather than keep it for a third year, even if you are past the usual date. Germination rate goes down to 50% after a couple of years, and the plants won’t be sturdy.

Barbara Pleasant tells us two other ways cover crops can improve soil: Rhizodeposition and bio-drilling.

Rhizodeposition is a process whereby plants release sugars and other substances through their roots. The root tips host colonies of helpful microorganisms that go deeper as the roots grow deeper.  For rye, this depth can reach 6 feet (2 m)!

Bio-drilling is what happens when cover crop roots “drill” into compacted subsoil. Oilseed and daikon radishes are cover crops famous for this action. The roots push deep into tight subsoil. Bio-drilling also happens when deeply rooted cover crops penetrate the subsoil and then die. With winter rye this can happen when the headed-up rye is mowed close to the ground in spring, or the rye is tilled into the top soil, severing the roots below till level. The next crop can follow the root channels made by the cover crop. This gives access to nutrients (including dead roots and microbes) left behind by the cover crop.

How to protect the soil over the winter if it is too late for cover crops

Carrot harvest cart. Our Danvers carrots have plenty of sturdy leaves to protect the soil over winter. Photo Mari Korsbrekke

Sowing cover crops too late means you don’t get enough growth in the fall, and the soil is not adequately protected from erosion or from weed growth over the winter. Try really hard not to leave bare soil over the winter.

If it’s too late to sow cover crops, but you do have a healthy growth of weeds, mow them at the beginning of November and then leave everything alone until early spring. The weed roots will hold the soil together and the above-ground growth will protect the soil from heavy rain. Having live plants will provide food for the microbial life in the soil.

If you don’t have weeds, but only almost bare soil, and it’s too late to sow cover crops, find some kind of organic mulch to cover the soil. When we harvest our storage carrots in November, we return the cut tops to the soil surface. Another seasonal option is tree leaves (sometimes conveniently left in bags by the curb). Best to ask the “owners” before lifting them. Other ideas include straw or hay. Woodchips or sawdust will work for winter protection, but don’t till them in when spring arrives. Rake them off and compost them nearby. If turned under, they use up a lot of nitrogen decomposing, and your crops will be starved.

More resources on cover crops

My book Sustainable Market Farming has a chapter on cover crops and many pages of charts about particular options.

Cover of Managing Cover Crops Profitably book from SARE

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.