Weed of the Month for May: Galinsoga

People in early spring weeding spinach that has been hooped and covered overwinter.
Photo Wren Vile

This is the first of my new monthly series of posts. All about weeds.

Sustainable (or Ecological) Weed Management: A Holistic Approach to Organic Weed Management

In the early days of organic farming, maximum use was made of frequent cultivation to kill weeds. Now we know that too-frequent cultivation risks causing soil erosion, and that each tilling or deep hoeing stirs air into the soil and leads to a burning-up of organic matter. The practice of sustainable weed management is about effectiveness – including removing weeds at their most vulnerable stage, or at the last minute before the seed pods explode – and ignoring weeds while they are doing little damage. Work smarter, not harder!

Start with restoring and maintaining balance in the ecosystem. Develop strategies for preventing weeds and for controlling the ones that pop up anyway. An obvious point is to avoid adding new kinds of weeds to any part of your fields. Remove the hitch-hikers from your socks out on the driveway, not when you notice them as you squat to transplant onions! We use our driveway as a convenient place to “roadkill” particularly bad weeds by letting them die in the sun. Beware of Trojan plant swaps!

Weeding in early June. Photo Lori Katz

Weeds are not a monolithic enemy, but a diverse cast of characters. Applying biological principles is not an attitude of war, but more like ju-jitsu, using the weaknesses of the weeds to contribute to their downfall. Develop an understanding of weeds and the different types: annual/perennial; stationary perennials/invasive perennials; cool weather/warm weather; quick-maturing/slow-maturing; and what Chuck Mohler referred to as “Big Bang” versus “Dribblers”. In this monthly blogpost series, we’ll meet various types of weeds, and develop a broader understanding of how and when to tackle each kind.

One factor to consider is how vulnerable the crop is to damage from that weed at that time. Weeds that germinate at the same time as a vegetable crop usually do not really affect the crop’s growth until they become large enough to begin competing for moisture and nutrients. These early weeds have the greatest potential for reducing crop yields if allowed to grow unchecked. We need to cultivate or otherwise control weeds before this 2- to 3-week grace period is over.

Weedy sweet corn. ideally, we would have cultivated two weeks and four weeks after sowing. Photo Bridget Aleshire

The critical period for weed control for the crop is the interval from the end of the initial grace period until the end of the minimum weed-free period, which is approximately the first third to one half of the crop’s life. For vigorous crops like tomato, squash and transplanted brassicas this is four to six weeks; less vigorous crops like onion or carrot need weed-free conditions for eight weeks or more. During that period it is essential to control weeds to prevent loss of yield.

Weeds that emerge later have less effect, and ones that emerge quite late in the crop cycle no longer affect the yield of that crop, although there are long-term reasons for removing weeds to improve future crops.

Know Your Weeds

Lettuce with weeds, easily hoed. Photo Bridget Aleshire

Learn to identify the major weeds on your farm, and any minor ones that suggest trouble later. Observe and research. Start a Weed Log with a page for each weed. Add information about your quarry’s likes and dislikes, habits and possible weak spots. Find out how long the seeds can remain viable under various conditions, and whether there are any dormancy requirements. Note down when it emerges, how soon it forms viable seed (if an annual), when the roots are easiest and hardest to remove from the soil (if a perennial), what time of year it predominates, which plots and which crops have the worst trouble with this weed. Monitor regularly throughout the year, each year. Look back over your records and see if anything you did or didn’t do seems to have made the problem worse or better.

Next think about any vulnerable points in the weed’s growth habit, life cycle, or responses to crops or weather that could provide opportunities for prevention or control. List some promising management options. Try them, record your results, decide what to continue or what to try next.

Most weeds respond well to nutrients, especially nitrogen. If you give corn too much nitrogen, even as compost, the corn productivity will max out and the weeds will use the remaining nutrients. Some crops, like carrots and onions never cast much shade at any point of their growth, so that sun-loving weeds like purslane are more likely to thrive there, but not be a problem for crops which rapidly form canopies that shade the ground.

Galinsoga – a fast growing, fast-seeding weed of cultivated soil.
Photo Wren Vile

Galinsoga

This month’s Weed Character is galinsoga, a “Seed Dribbler”, that matures seed while still quite small plants, sheds some, makes some more, and can carry on for a long seed-shedding season.

Encouraging information is that a constant percentage of the seeds that are still left from one year’s shedding dies each year. This varies widely among species – for lambsquarters it’s 31% per year in cultivated soil (only 8% in uncultivated soil). The number of seeds declines rapidly at first, but a few seeds persist for a long time.

While seeds survive better deeper in the soil, they don’t germinate better down there. Larger seeds can germinate at deeper levels than small seeds. If you are trying to bury seeds deep, use inversion tillage, don’t rely on rotavating, as seeds somehow manage to stay near the surface with rotary tilling. Chuck Mohler, author of the excellent book Manage Weeds on Your Farm, has tested this out with colored plastic beads.

We have two kinds of galinsoga: narrow-leaved and hairy. Both behave the same way. They thrive in highly fertile, freshly tilled soil, just the same as you hope your vegetable seeds will. Mostly we think about how to get rid of galinsoga (prompt hoeing or other cultivation before it flowers), or stop it germinating in the first place (mulches). Its flowers attract beneficial insects such as hoverflies, and it can be eaten by humans and livestock. Young leaves can be used in a soup or in mixed dishes. It doesn’t have a strong flavor. The plants contain flavonoids and phenolic compounds, and it has been found to have antioxidant and anti-inflammatory properties. Extracts from hairy galinsoga can coagulate blood. It is an alternate host for certain nematodes and over twenty insect pests. Hairy galinsoga is thought to have originated in Central and South America, and has become naturalized in North America and other temperate and tropical regions.

Galinsoga is a summer annual that belongs to the sunflower family (Asteraceae) and can invade vegetable gardens with dense infestations that crowd out crop plants. The secrets of galinsoga’s success are that its seeds germinate immediately they reach the soil (no dormancy period), it grows very fast, shading out other plants, it sets seed in as few as 30–40 days after emergence, and continues shedding seed as long as it is growing. It also has the knack of re-rooting if pulled and laid on the surface of the bed, if there is any moisture in the soil. Large plants seem able to transfer the water in their cells to their roots, helping re-rooting happen. Seed that is shed early in the year is capable of growing a mature plant very quickly. There can be multiple generations in one warm season. Fortunately, the seeds are short-lived, and have to be in the top 0.25″ (6mm) of the soil to germinate.

Hoe weeds while they are small and you’ll be rid of those with short-lived seeds in a few years. Galinsoga and Outredgeous lettuce.
Photo Pam Dawling

Galinsoga Identification

Hairy galinsoga (Galinsoga quadriradiata), has profuse hairs on stems and leaves. Narrow-leaved galinsoga ( Galinsoga parvifolia), is very similar, except it is not hairy and it has narrower leaves. Leaves are oval with serrated margins and distinct petioles. They are arranged opposite each other on the stems. The flowers have densely packed yellow disc florets and five tiny white ray florets, each with three scalloped teeth at the end. Seeds of hairy galinsoga germinate between 54°F-86°F (12°C-30°C) with an optimum temperature requirement of 68°F-75°F (20°C-24°C). Most of the seed germination occurs from May to June, after the last frost. It flowers abundantly from about late-May until late fall here in central Virginia. Fallen seeds can germinate immediately due to the absence of dormancy requirement. Take advantage of this phenomenon to eradicate hairy galinsoga from an infested field in three to four years by careful management.

Controls for Galinsoga

Prevention of Weed Germination

Hoeing or mechanical cultivation is effective if carried out repeatedly during the early stages of growth (before flowering). Mulches, such as thick (6-mil) black plastic, or straw, hay, leaves, woodchips over cardboard or newspaper, are effective to control galinsoga in small gardens if applied immediately after planting the crop and before the galinsoga germinates.  Tarping is the equivalent solution for larger areas.

Reduction of Weed Seeding

Grazing, or the mechanical equivalent, mowing, will take care of galinsoga in places you are not currently growing a crop. This weed is not usually found in lawns. It has no resistance to frost. Livestock will happily graze it.

Reduction of Viability of Seeds

Most weed emergence happens within two years of the seeds being shed. Not all seeds that are produced will ever get to germinate (I was very pleased to learn that seeds have many ways of not succeeding!) You can help reduce their chances, by mowing crops immediately after harvest, (to prevent more weed seed formation); then wait before tilling to allow time for seed predators to eat weed seeds that already produced. Seeds lying on or near the soil surface are more likely to deteriorate or become food for seed predators than buried seeds, so delaying tillage generally reduces the number of seeds added to the long-term seed bank. (Short-term, they may germinate!)

If they do not get eaten, dry out or rot, seeds on top of the soil are more likely to germinate than are most buried seeds, and small, short-lived seeds of weeds which have no dormancy period, such as galinsoga, will almost all die within a year or two if they are buried a few inches.

Putting it Together

Strategies include

  1. Inversion tillage such as moldboard plowing (seeds will die off deep in the soil within a year or so.)
  2. Mulching – the seeds will not germinate or be able to grow through the mulch, and will be dead by next year. Be sure to rotate the mulched crops around the farm, so that the benefits are not confined to one section;
  3. Grazing with small livestock, or harvesting galinsoga for human consumption, or mowing: especially mow as soon as the food crops are finished, if you cannot till right away.
  4. Tarping (mow first);
  5. No-till cover crops, with summer crops transplanted into the dying mulch;
  6. Stale seed bed techniques, including flaming;
  7. Plant flowers that attract beneficial insects, particularly seed-eating insects, and birds.
Front cover of manage Weeds on your Farm

Resources on Weeds

That New GMO Tomato, and other GMO vegetables

Blueberries, naturally high in anthocyanins.
Photo Marilyn Rayne Squier

In February this year I learned about a new genetically modified tomato, the Purple Tomato, that is to be marketed directly to gardeners and farmers. Up until now, genetically modified vegetables have been few and those seeds were not available to the public, only to large commercial growers. I know from looking at the stats on my website that GMO foods are a big concern for my readers, and I decided to do more research. See my earlier post Which Vegetables are Genetically Modified?

Concord grapes ripening. Photo Kati Falger

This very purple cherry tomato is the color of Concord grapes, with insides the color of Victoria plums. The creators of this odd fruit worked for 20 years to get this color, which they transferred from snapdragons. Snapdragon flowers are edible, in case you wondered. They have a bitter flavor, like chicory. But it’s the color genes the breeders transferred, not the flavor genes. This fruit was made by Norfolk Plant Sciences. The color genes indicate high levels of anthocyanin, the pigment in other purple foods. Anthocyanins provide anti-inflammatory and anti-cancer benefits. Anthocyanins can be found in other purple and blue foods such as blueberries, eggplants, blackberries, red cabbage, purple sweet potatoes and purple broccoli. The Purple GMO Tomato contains similar levels of anthocyanins to other purple foods.

Epic eggplant from Osborne Seeds. Another high anthocyanin food

Norfolk is hoping to change diners’ and gardeners’ perceptions of GMO foods by selling something we will consider healthy as well as exciting. Only 7% of Americans think that GMO foods are more healthy than non-GMO foods, with most believing they are less healthy.

Cathy Martin, the creator of the Purple Tomato reports that research published in Nature found that mice who ate a diet supplemented with purple tomatoes lived 30% longer than those who didn’t. Anyone who wants longer-lived mice knows what to do!

Pink Boar tomato.
Photo Pam Dawling

Modern domesticated tomatoes have anthocyanins only in the non-edible foliage. It is entirely possible to breed tomatoes the conventional way, with anthocyanins in the fruit as well as the leaves and stems. Jim Myers at Oregon State University bred the Indigo Rose tomato, which is available to gardeners. The variety has been improved since its early days. We grew it when it was new and were disappointed with its flavor and the fact that the purple stage was under-ripe. Fully ripe fruits were a dark brownish-red shade. Indigo Cherry Drops is a more recent variety from the same breeders, and there are now over 50 Indigo cultivars.

Those who want more anthocyanins in their food can choose Indigo tomatoes and plenty of other blue and purple vegetables and fruits. The U.S. Food and Drug Administration says there is no health risk to eating GM foods currently on the market. Each person can make their own decisions.

Purple Galaxy is another GMO tomato variety, despite earlier claims to the contrary.

 

Non-GMO Project symbol

The Non-GMO Project has more info about                                                                the purple GMO tomato.                                                                       

Other GMO Food Crops

You can read about other GMO food crops in this List of Bioengineered Foods from USDA

Apple (ArcticTM varieties) (pdf) are being grown in Golden Delicious, Granny Smith and Fuji varieties. Only those trademarked ArcticTM are bioengineered. Regular Fuji, Granny Smith and Golden Delicious are not GMO.

China and the US are growing GMO papaya, a disease resistant variety that resists Papaya Ringspot Virus. Chinese papayas are not imported to the US, but all US-grown papaya (mostly grown in Hawaii) can be assumed to be GMOs.

GMO eggplants are grown in Bangladesh, but not imported fresh into the US. I don’t know about pickles.

Pink-fleshed pineapples grown in Costa Rica, are sold by Del Monte in the US. Yellow-fleshed pineapple can be assumed to not be GMO.

Many commercial potato varieties sold in the USA and Canada are GMOs. Trademarks include New LeafTM, and various versions of InnateR.

GMO Yellow crookneck squash comprise about 10% of that sold commercially in the US.

All sugar beet grown in the US and Canada can be assumed to be genetically modified. The FDA has approved two varieties of GMO Sugarcane to be used for food and feed. In 2013, about 55% of US sugar was from sugar beets, and 45% from sugarcane.

But until the Purple Tomato, no GMO vegetable seeds were available for the public.

If you want to avoid GMO vegetables

Grow your own – you’ll know exactly what went into them. Just avoid buying the GMO Purple Tomato seeds.

Buy from a trusted grower.

Buy from a certified Organic, Real Organic, Non-GMO, or Certified Naturally Grown farmer. Organic certification prohibits GMOs. CNG closely follows the Organic standards, using a peer-inspection system.

USDA Organic symbol
Real Organic Project logo
Certified Naturally Grown logo

Lettuce Growing Tips

 

Our first outdoor lettuce bed in May.
Photo Wren Vile

 Lettuce growing conditions – germination

  • Lettuce seed needs light to germinate – don’t sow too deep: 1/4″–1/2″ (6–10 mm) is ideal.
  • Minimum soil temperature for germination is 35°F (1.6°C).
  • Optimum temperature range for germination is 68°F–80°F (20°C–27°C). I have a table of optimum soil temperatures for germination in my book The Year-Round Hoophouse
  • Germination takes 15 days at 41°F (5°C), 7 days at 50°F (10°C), 3 at 68°F (20°C), only 2 days at 77°F (25°C)
  • Germination takes 3 days at 86°F (30°C), but will not occur reliably at temperatures hotter than that.
  • A soil thermometer soon pays for itself and saves lost crops and frustration.

Lettuce crop requirements

  • Free-draining soil, high organic matter, pH 6.0–7.0.
  • Fertile soil with good tilth will help roots grow.
  • Don’t overdo the nitrogen – encourages E. coli.
  • Keep lettuce growing quickly for good flavor – plenty of water throughout its growth.
  • Ideal growing temperatures 60°F–65°F (15°C–18°C).
  • Some growth whenever the temperature tops 40°F (4.5°C).
  • Cultivate regularly and shallowly to remove weeds.
Lettuce nursery bed with soil thermometer behind the sheep
Photo by Bridget Aleshire

Sowing lettuce for transplanting

  • You can sow in cell-packs or plug flats, 3 seeds per 1″–2″ (2.5–6 cm) cell, later reducing to 1 seedling with scissors.
  • If suitable germination space is limited, sow seed in a small flat or shallow pot, then spot the tiny seedlings into bigger flats or 606-cell packs (2″ × 2″, 5 × 5.6 cm) to grow on before planting out.
  • Can use an outdoor nursery bed from mid-April to October, rather than flats. Transplant the bare-root plants directly from the seedbed.
  • But in very hot weather, indoor sowings might give more reliable germination.

Transplanting lettuce

  • Harden off before transplanting.
  • Transplant lettuce seedlings at 4–6 true leaves, 3–6 weeks of age depending on how fast they are growing.
  • Handle transplants only by their leaves or the root ball—try not to touch the roots or stem. This minimizes the damage from your hands.
  • 8″–12″ (20–30 cm) spacing for full-sized heads. Close spacing lets foliage cover the bed completely, creating a cooler microclimate.

Lettuce Types

  1. Iceberg (crisphead) lettuces have little nutritional value. They have no frost tolerance because of their high water content. 75-100 days from direct seeding.

    Buttercrunch Bibb lettuce. Photo Kathleen Slattery
  2. Butterheads (bibbs) have very tender leaves, but have shorter shelf-life than romaines and leaf varieties. 60-75 days from direct seeding.
  3. Romaine (cos) lettuces are upright, often very crisp and flavorful. They have more vitamins than other lettuce types. &0 days or more from direct seeding.

    Green Forest romaine lettuce.
    Photo Pam Dawling
  4. Leaf lettuces include the familiar oak-leaf types, and frilly ones. You can harvest individual outer leaves or cut the whole plant. 45-60 days from direct seeding.
  5. Batavian lettuces (summer crisp or French crisp) are tasty, thick-leafed varieties that have great heat and cold tolerance. Although sometimes classified with icebergs as crisphead types, they are very different.
  6. Multileaf lettuces – familiar Tango, Panisse and Oscarde, and the newer Salanova, Multileaf and Eazyleaf brands. They are bred for uniformly small leaves, with more texture, loft and flavor than baby mixes and faster harvesting. Transplanted 6″–8″ (15-20 cm) apart they produce 40% more than baby leaf mixes. The full-size plant can be harvested as a head, providing a collection of bite-sized leaves. Or just one side (or the outer leaves) of the plant can be cut and the plant will regrow for future harvests. Growing multileaf heads takes 55 days, compared to 30 days for baby lettuce. For the most harvest, pick the outer leaves and let the middle regrow.

    Ezrilla Tango-type one-cut multileaf type lettuce
    Photo High Mowing Seeds
  7. Baby lettuce mix, aka mesclun, salad mix, spring mix and misticanza. Some mixes include other greens. 21 days from seeding in mild weather. Up to 63 days in cold weather.

Lettuce varieties for every time of year

We used to reckon on five lettuce seasons, but with climate change, our Early Spring shrank and became encompassed in our Spring, so now we have 4 lettuce seasons, and we always sow 4 diverse varieties:

  • Spring (Jan 17 – April 22), 8 sowings. Priorities: fast growth, cold tolerance
  • Summer (April 23 – Aug 14), 20 sowings (lots of seed!). Priority: extreme heat tolerance/bolt-resistance. I just sowed our first batch of summer varieties on April 23
  • Fall (Aug 15 – Sept 7), 9 sowings. Priorities: some warmth-tolerance, some cold tolerance
  • Winter (Sept 8 – 24), 9 sowings. Priority: cold-tolerance

Season extension techniques for lettuce in spring

  • Fast-maturing hardy varieties
  • In early spring, use transplants for earlier harvests
  • Warm microclimates (protection from prevailing winds)
  • In spring, warm the soil with black plastic mulch
  • Use rowcover
  • Harvesting early in the year might mean fast production in January and February, or it might mean starting in the fall and overwintering the plants. See my post series Lettuce of the Month, for ideas on varieties and techniques throughout the year. See here for the overview.
A stormy early spring day, garlic, rowcovered beds and our hoophouse.
Photo Wren Vile

Avoid lettuce bolting

Assess your risks and if in doubt, harvest early. Bolting and/or bitterness are more likely with

  • Under-watering,
  • Long days,
  • Mature plants,
  • Poor soil,
  • Crowding,
  • High temperatures,
  • Bolt-resistance generally goes from Leaf types (first to bolt), through Romaines, Butterheads, Bibbs, to Crispheads.
  • Vernalization—once the stems are thicker than 1/4″ (6 mm), if plants suffer 2 weeks of temperatures below 50°F (10°C), followed by a rapid warm-up.
  • Also see What makes vegetable crops bolt and how can I stop it?
You don’t want this! Bolting lettuce outdoors in July
Photo Alexis Yamashita

Keys to year-round lettuce success 

  • Store seed in a cool, dry, dark, mouse proof place.
  • Good soil preparation and high organic matter are important for high quality lettuce, which needs to grow quickly.
  • Location, location, location! We grow lettuce outside from transplants from February to December (harvesting from late April); in a solar-heated greenhouse from September to March (harvesting leaves from November) and in a solar heated hoophouse from October to April (harvesting leaves from November, and whole heads in April). We also sow baby lettuce mix in the hoophouse from October to February, for harvest multiple times from December to April.
  • Use shade cloth on hoops in hot weather
  • Use rowcover in cold weather, or plant in cold frames, greenhouses or hoophouses.

Scheduling lettuce for continuous harvests

  • Lettuce grows faster at some times of year than others, and the time between one sowing and the next needs to vary to balance this.
  • To harvest a new planting every week you need to have sowing gaps of more than 7 days in the spring, 6-7 days in the summer, less in fall.
  • In warm spring weather, baby heads of lettuce or individual leaves can be ready to harvest 4 weeks after transplanting, and full-sized heads 6 weeks after transplanting.
  • In summer, full-size heads can be ready in as little as 3 weeks from transplanting.
  • As temperatures and day-length decrease in the fall, the time to maturity lengthens, and a single day’s difference in sowing date can lead to almost a week’s difference in harvest date.
  • Lettuce for harvest in February will take 2-3 times as long from planting to harvest as that for September harvest.
  • December and January sowings grow very slowly, and early February sowings will almost catch up.
Flats of lettuce transplants in our cold frame in April.
Photo Pam Dawling

Scheduling lettuce January-June

January: sow every 2 weeks

  • Sow indoors in flats in late January for outdoor transplants
  • If you have a greenhouse or hoophouse, transplant there until mid-February
  • Harvest leaf lettuce and baby lettuce mix from protected crops

February: sow every 2 weeks

  • Same as January

March: sow every 13 days, indoors in flats

  • From late March or early April, you could switch to outdoor direct sowing. (We transplant all our lettuce.)
  • Transplant the first 3 sowings outdoors with rowcover
  • Harvest leaf lettuce, baby lettuce mix from a hoophouse; starting late March, harvest leaves from the first outdoor planting

April: Sow every 9 days

  • Transplant the March sowings
  • Harvest whole heads from late April

May: Sow every 8 days

  • Transplant 1 week’s needs each week
  • Harvest outdoor heads

June: Sow every 6 or 5 days, under shadecloth

  • Transplant one week’s needs every 6 days, using shadecloth for the first 2 weeks
  • Harvest outdoor heads

See my post Lettuce All Year in a Changing Climate, which includes links to my slideshow about growing lettuce year round, and our Lettuce Varieties list and Lettuce Log (planting schedule). It also includes keys to succeeding with year-round lettuce (dates for succession planting).

Lettuce bed in May.
Photo Wren Vile

Book Review The New Seed Starters Handbook, Nancy Bubel with Jean Nick 2018

 

The front cover of the New Seed Starters Handbook, by Nancy Bubel with Jean Nick

 

The New Seed Starters Handbook, Nancy Bubel with Jean Nick 2018, 452 pages, 6.5 x 9.1 inches approximately, with drawings and tables throughout. $19.99 Rodale Books.com. Distributed by Penguin Random House.

This 2018 edition is an updated version of the old favorite 1988 reference book by Nacy Bubel explaining how to start seeds and grow healthy seedlings of vegetables, fruits, herbs, flowers, trees and shrubs; how to tackle seed-starting problems, and where to find seeds and gardening supplies. It includes an encyclopedia section listing more than 200 plants, with details on how to start each kind from seed. The 1988 book has been a very trusted resource for me for over 30 years, particularly the tables, which have information I found nowhere else in the pre-internet days. The newer version is not much changed. It has a retro cover and is labelled as a Rodale Classic. Some post-1988 tools and resources are included, and the trend towards smaller households is taken into account. The delightful drawings by Frank Fetz remain. It has a few black-and-white photos, although the cold frame photo in my copy is rotated 90°! This is a book primarily for backyard gardeners, but there is valuable information for growers on much bigger scales, especially in the tables.

Jean NIck, who updated Nancy Bubel’s book

Jean Nick is a longtime organic gardener, sustainable farmer, environmentalist and freelance writer and editor. Jean keeps the voice of Nancy Bubel, so the updates blend in smoothly.

If you have the original (1978) Seed-Starter’s Handbook, you’ll have missed all the improvements Nancy Bubel made during the ten years before The New one came out. If you have the 1988 edition and have kept up a bit with gardening topics, I doubt you need to buy the 2018 edition. If you are a relatively new grower, and Nancy Bubel’s work is new to you, I recommend buying this book for its broad collection of information and clear tables, drawings and explanations. Some of the tables come from Knott’s Handbook for Vegetable Growers, now a $90 investment.

The table of temperatures needed to kill soilborne pests is the first example of the feature of the book that I have turned to most often over the years. There is now an expanded table of when to start various seedlings and when to plant them out, referenced to your average last spring frost. The sowing checklist has been tidied into a more logical order. This book includes gems of information such as how to break seed dormancy with cold or light. Germination of onions and chives appears to be retarded by exposure to light, but lettuce and celery germination is helped by light if the temperature is higher than that at which they normally germinate best.

The chapter on light has been brought forward to a better place in the book, before seeds are sown. The science of lighting has changed since 1988, with different types of lighting available and newer information on what plants need, and do best with. Incandescent lights have gone, LED lights and high-intensity discharge lamps have arrived. Here’s a chapter where revision is really valuable, not forgetting that dusting light tubes and bulbs still makes a difference, and plants short of light still do better if the temperatures are cool.

Here’s another aspect of Nancy Bubel’s writing that I appreciate: the scientific explanations of how biological changes happen. For example, in the process of germination, starches and proteins change into simpler forms before they can dissolve in water and become available to the germinating seed. The enzymes needed to split the complex molecules into simpler ones act in response to the increasing respiration of the seed as it breaks dormancy. Reality check: Even dead seeds can absorb water: plumped-up seeds are not proof of life.

Next come my three favorite tables (copies of which are posted on our germination cabinet): Ideal Temperatures for Germination of 27 crops; the Number of Days to Germinate at Various Temperatures from freezing point to 104°F (40°C); and The Percentage of Normal Vegetable Seedlings Produced at Different Temperatures. This is where I learned that you might get spinach to germinate at 68°F-86°F (20°C-30°C), but you’ll get decreasing levels of normal seedlings, down to one third. These three tables enable growers to aim for the ideal temperature, know when to resow if nothing has come up, and the unintended consequences of sowing crops too far outside their optimal range.

Start seeds warm and grow seedlings cool. Chill tomato plants as soon as the seed leaves open, to get earlier and heavier fruiting: keep them at 52°F-56°F (11°C-13°C) for 10-21 days. The construction of the first flower cluster is determined 4-6 weeks before flowering, when the seed leaves just opened. Similarly for peppers. Many of us have accidentally achieved these results when we started those crops extra early and they emerged into a chilly greenhouse.

Nancy Bubel collected moss from her woods, tore it up and lined the base of pots and flats. Those of us who know how slowly mosses grow will not follow that advice, and Jean Nick marks it as optional. Our increased awareness of the importance of sustainability, and of the carbon-sequestering role of peat moss left me surprised to see that although there is an unflinching discussion of the issues, sphagnum moss and peat moss are still recommended. Worm castings, composted bark, coir and rice hulls are listed as alternatives, without discussion of the ecological costs of removing agricultural “waste products” across half the globe to another country.

The Growing On chapter has information about watering and fertilizing (soaking eggshells in water as a fertilizer has been dropped). The importance of air movement has been added. Next are preparations for moving your plants outdoors. This starts with knowing suitable conditions for working up the soil, and how to make life easier by using permanent beds where the soil stays loose. Jean Nick has added information on soil structure and the mycorrhizal fungi that associate with many crops, improving the soil structure. Double-digging has been back-burnered. Tilling and digging break up the mycorrhizae, so doing less tillage is advantageous, as is growing a diversity of plants in close association, and keeping live roots in the soil. Options for ways to start a new garden are explained, including sheet mulching.

The chapter on the garden diary has been moved forward, so we learn about it before we start planting outdoors, and a short paragraph about calendar apps, photo records and blogs has been added. Garden Mapping comes next, with a two-plus page table of recommended inter-plant and inter-row spacings. A paragraph about modern weather-forecasting has been added, with advice to take the time to pay attention to local weather and microclimate. This chapter includes choosing suitable weather conditions, time of day and suitable sized plants, and developing good judgement, green thumbs and good planting techniques.

The 1988 version of this book was where I learned about phenology, studying the cycles of development of living things unfolding through the year, and linking various agricultural events with particular natural developments. There is much in the encyclopedia section. Spring peepers start really early, and rather than being a sign to plant something, they can be a sign to look for soil dry enough to till. I also found value in the list of conditions that mean a frosty night is likely.

The chapter on care of young transplants includes mulching, but no longer recommends old carpets (synthetic these days, not wool), and adds in paper roll mulch, biodegradable and other plastic sheet mulches. Protection for new transplants has changed from tall bushel baskets to floating row cover. Glass cloches have been replaced by water walls (double walled containers to set round the plants and fill with water for insulation) and plastic gallon jugs with the bottoms cut out. The chapter on cold frames and hotbeds has been moved later and been combined with info on greenhouses. Most of the rearranging of chapters makes sense timewise, but this one was counter-intuitive for me.

Kelp sprays help plants resist frosty temperatures: tomato plants survive 29°F (-2°C). Celery plants sprayed at 20 days after emergence with a 1:100 solution of seaweed extract grew larger stalks than untreated plants. Snap beans sprayed with seaweed one week before bloom gave a 10% yield increase on the first picking. Weekly spraying of cucumber plants while fruiting increased the harvest by almost 42% in a 3-year study. I’m leery of spraying anything on cucurbits, as I’ve had problems that way. This book has how to make your own kelp spray from scratch. For those near the sea. Compost tea and comfrey tea have been added as fertilizers. Here’s how to make them. True compost tea is aerated while brewing. With all these concoctions, be sure you start with healthy ingredients, to avoid brewing more bad germs, which could make you ill.

The chapter on fall gardening includes a useful table on determining your last planting date for many crops, taking account of cold-hardiness, days to maturity, days to transplanting, 14 days for the “short day factor” (because daylength is shortening), and 14 days to allow for the possibility of an early frost. The combination of these factors tells you how many days to count back from your average first frost date.

Up next are pests, both insects and other animals. The newer edition has helpful damage-reducing advice using methods causing minimal collateral damage: using row cover, spraying fairly hard with water, homemade garlic and cayenne sprays, neem oil, insecticidal soap, and Bt for suitable insects. Those instructions are followed by specific info for particular pests.

The section on hoophouses says to build your own from metal conduit and builders’ plastic, although the following paragraph says that kind of plastic will disintegrate in 6 months (and be cloudy before that). If you’ve ever gathered up plastic shards from your garden, you won’t use builders’ plastic again! Solar greenhouses can be an attractive idea, but you can get the same space in a hoophouse (high tunnel) compared to a greenhouse, for a quarter of the cost. Because the structure of a high tunnel is less massive than a glass-covered greenhouse, more light reaches your crops in a high tunnel, and growth is faster.

The chapter on greenhouse growing covers temperature and humidity and when to start seedlings. Humidity of 45-60% works well, even 70%, but 90% is too damp, and may lead to fungal diseases and algal growth. The plant diseases section includes growing conditions less likely to promote diseases, choosing resistant cultivars, monitoring plants, practicing good sanitation, and providing airflow.

“Why seed saving and storing are important” has been moved forward in the 2018 edition, sending the wildflowers and trees back into the encyclopedia part of the book with other specific crops. Before starting to save seeds, understand how seeds form. A new sidebar explains how to avoid GMO cross-pollination. Understanding seed isolation is also useful since the arrival of Super-sweet corns, which need to be isolated from all other types of corn. Likewise, this will help in understanding squash pollination groups and brassica families.

Next is information on how to develop a crop strain suited to your locality. Here is an explanation of what a hybrid is, and why saving seeds from hybrids is challenging, produces seeds inferior to your starting material and doesn’t lead to quick improvements.

“You have more to lose than to gain from saving seeds of garden hybrids.” Nancy Bubel.

When harvesting a seed crop, it’s important they are mature. Here’s brief info on cleaning, sorting, drying and winnowing, salt-water treatment, hot water treatment and fermentation to kill seedborne diseases.

Seeds need to be very dry when put into storage and after that. No paper packets on shelves! Between 32°F and 112°F (0°C – 44°C), for every 9F (5C) that the storage temperature is lowered, the duration of viability of the seeds is doubled. Increasing the moisture content of lettuce seeds by 5-10% results in a faster loss of viability than increasing the storage temperature from 68°F (20°C) to 104°F (40°C)!  The sum of the humidity and the temperature in °F should be less than 100.

The chapter on viability of seeds includes how to test germination rates, and a money-and-time-saving table of how many years after production each kind of vegetable seeds will last. The table is from the 1980 Knott’s Handbook for Vegetable Growers and is unchanged. This is followed by seed-saving tips for specific plants, and tips for plant breeding, such as how to hand-pollinate, save pollen for later, and how to sell your seeds or plants.

Seed banks are valuable resources for preserving genetic diversity and distributing seed genetics widely. They provide resilience in the face of disasters such as new diseases or calamities at a particular seed warehouse. Their work is valuable in keeping genetic material available to all, not just in the hands of multinational corporations.

Most of the rest of the book is an encyclopedia of plants to grow from seed. The detailed information relates to temperature and phenology, not the calendar. This is a great source, that will help you try new crops that previously might have struggled in your bioregion, especially if you only had planting dates, not conditions.

Here are some examples: Sow parsnips when the daffodils bloom; sow peas up until 2-3 weeks before the last frost (after that there is not enough cool weather left to mature a good crop); sow chard when maples bloom; edamame when apple blossom starts to fall or when the oak leaves are the size of mouse ears; sow asparagus seed in spring at the same sign as edamame, or in the fall. Sow peanuts when maple leaves are the size of squirrels’ ears; adzuki beans when the soil temperature is above 60°F (16°C); Lima beans when the soil is at least 70°F (21°C), when peonies are in full bloom; sow winter squash and pre-sprouted cucumber seeds when the late irises bloom; plant out tomatoes when you’re fairly sure your last frost has passed, about the time the barn swallows return.

To my surprise, the book recommends growing potatoes from spuds left from last year’s crop. I wouldn’t do this because of the diseases that can spread.

After the vegetable and fruit section are chapters on growing herbs, garden flowers, wildflowers, trees and shrubs from seed. This is where I learned to nick redbud seeds, pour boiling water on them and let them soak for a day to break dormancy. The newer edition has a sidebar on invasive trees and shrubs, and advocates for responsibility in what we plant and what we let grow. The updated list of sources of seeds and supplies includes websites and phone numbers. There’s a 23-page index (considerably fuller than the earlier edition).

Nancy Bubel wrote a great book, including very accessible information not found in many gardening books. If you have not got the previous edition, do buy the 2018 one. If you still have the previous one, and access to other books and the web, I would not rush to buy this edition – not so much is new.

Organic No-Till Cover Crops

 

Rye and hairy vetch cover crop. Photo Kathryn Simmons

Organic no-till cover crops are grown to flowering (or very close), killed without tilling or chemicals, and left to become dead mulch for the next crop. The food crops are planted into the dying residue. We have used no-till cover crops for Roma paste tomatoes, which are transplanted in early May. We don’t need early-ripening for these, making them a good no-till food crop. This method enabled us to have 1 year in 10 as a no-till year.

Four ways to kill cover crops without herbicides or tilling

  1. Winter-killed cover crops for early spring food crops
  2. Mow-killed cover crops.
  3. Crimped and rolled cover crops use special tractor equipment. A crimping roller is more successful than a smooth roller. I have also seen photos of an energetic human-powered method involving a T-post lying on the ground across a bed, with two well-coordinated people, one at each end of the T-post, lifting the post with a loop of rope or twine, setting the post back down a few inches further forward and stepping on it.
  4. Mowed and tarped cover crops, kept covered until the roots of the cover crop are dead. With this method, the cover crop or weeds can be killed at any stage of growth. I’m still learning about this, so I won’t say more this time.
We can no longer rely on our winter cover crop oats getting winter-killed. March photo by Pam Dawling

Organic no-till benefits to the soil

  • Soil is kept covered, reducing erosion.
  • Soil compaction is reduced by having fewer tractor passes. Labor, fuel and machinery costs are also reduced.
  • Soil layers are not inverted, the soil micro-organism habitat is undisturbed, the root channels of the cover crops are undisturbed, and the number of earthworms and microbes increases.
  • Soil structure improves, organic matter increases and the cover crop biomass is conserved, rather than burning up as quickly as it would if incorporated.
  • Soil can absorb and retain more water, making it more resilient in drought. Yields are higher under drought conditions than on tilled soil.
  • Soil retains cooler temperatures into the summer, increasing root growth.
  • No new weed seeds are brought to the surface.
  • Some pathogens and pests may be suppressed.
  • Mulch grows in situ – no need to haul and spread.
  • Legumes in the cover crop mix can provide all the nitrogen the next crop needs. The cost of N from vetch seed is half the cost of N from fertilizers.
  • Legumes are a slow-release fertilizer: 15% of the nitrogen in the vetch is in the roots, in position in the soil for the new transplants. 50% becomes available to the food crop as the soil warms in spring and early summer; 50% remains for the following season.
  • Hairy vetch activates plant genes that increase disease tolerance and plant longevity, giving tomatoes an extra 2 to 3 weeks of production
  • Use of agricultural plastics is reduced.
  • If spring is wet, it may be possible to mow, when you couldn’t till.
  • Crops such as pumpkins are cleaner than those grown on bare soil.
Hairy vetch cover crop.
Photo Southern Exposure Seed Exchange

Suitable cover crops for no-till

  • When choosing winter annual cover crops, consider cold-tolerance, the length of the growing season, and efficacy in fixing nitrogen and producing biomass. Do you want a winter-killed cover crop (oats, sorghum-sudangrass) or a hardy one (winter wheat or winter rye)?
  • Using a mixture of grasses and legumes helps limit the loss of N from the cover crop through leaching or denitrification. Generally, use a grass/legume mix in a 2:1 ratio, although you can use higher amounts of legumes, up to 1:1. Hairy Vetch, Austrian Winter Peas, Crimson Clover are all suitable.
  • There are advantages to including more than one legume in the mix – in unusual weather, one may struggle, while the other does better. 

No-till cover crops for early spring vegetables

  • Frost-tender cover crops can be used before early spring no-till food crops. Some growers say it is best to mow or roll the cover crop at around the first frost date, to provide a more uniform mulch in the spring. Weeds may be a problem and the soil will be colder than bare soil — this may work for cabbage and broccoli.
  • For the very earliest spring crops, forage radish, lab-lab bean or bell beans will die back and leave almost bare soil. While they are growing, they suppress weeds.
  • BUT fast-maturing spring vegetables will not do well with no-till cover crops unless you add N fertilizer, as they need nitrogen more quickly than can be got from no-till cover crops early in the year when the soil is cold.
Winter rye and crimson clover cover crop
Photo by McCune Porter

No-till cover crops before suitable late spring vegetables

  • A 1994 USDA trial of various no-till cover crop mulches for tomatoes found that hairy vetch (without added nitrogen fertilizer, and without any weeding) out-yielded plastic-and-fertilizer plots by about 25%, and out-yielded fertilized bare soil by 100%.
  • Late-spring transplanted crops such as late tomatoes, peppers, eggplant, Halloween pumpkins, or successions of cucumbers and squash can do very well after a winter-hardy legume-grass mix no-till cover crop.
  • I have read that transplanting eggplant into crimson clover (sown in the fall before) will reduce flea beetle outbreaks, but I have yet to try it. Mowing after early bud stage will kill crimson clover.
  • At the Coastal Plain Experiment Station in Tifton, Georgia, they have trialed peanuts planted into crimson clover.
  • If you have machinery or hand tools for seeding into no-till cover crops, direct seeded crops are possible.
Rows of Roma paste tomatoes, some on bioplastic, some no-till. Credit Bridget Aleshire

Our example: Paste tomatoes in a mow-killed no-till cover crop mix

  1. We find a plot that will be available in early September: Our spring broccoli and cabbage finish in early July. We follow them with a round of buckwheat summer cover crop.
  2. Then, on September 7–14, we sow winter rye, Austrian winter peas and hairy vetch. 5 oz HV, 1.5 oz AWP, 2.5 oz Rye per 100 sq ft (5 g HV, 5 g AWP, 8 g rye/m2.)
  3. It is vital to grow a solid stand of cover crops for high biomass. The goal is to have the vetch be about 4″ (10 cm) tall before hard frosts of 22°F (-5.5°C) stop growth.
  4. We do not till in this cover crop in spring, but in early May, we mow it very close to the ground using our hay mower (5/1-5/5), just before our tomato transplanting date. We want the cover crop to stay in long aligned stems, not be chopped up small. For small patches, a scythe is better than a weed-whip, for the same reasons
  5. This kills the cover crops. If mowed too early, they will not die. The vetch should be flowering. Rye should be at the soft dough stage – bite a kernel.
  6. We let the mulch wilt for a day, making it easier to work with, before transplanting. We measure and set out stakes and ropes to mark the rows.
  7. We transplant the tomatoes into the dying mulch with as little disturbance of the cover crop as possible.
  8. The vetch and peas (if plentiful) supply all the nitrogen the tomatoes need. We do not add any compost or other fertilizer. The peas reduce the incidence of Septoria leaf spot in the following tomato crop.
  9. In our humid climate the dead no-till mulch keeps weeds away for 6 -10 weeks, by which time it has mostly biodegraded. In climates that are drier or cooler than ours, the mulch will last longer.
  10. In July we roll hay between the rows, to top up the mulch. We plant the tomato rows 5.5 feet (1.7 m) apart and the plants are staked and woven, so we can snugly fit big round bales of hay down the aisles.
  11. This crop doesn’t finish until the frost, and we have all the posts to remove before we can sow a cover crop, so the winter following the paste tomatoes, we usually grow rye with Austrian winter peas.
The Roma paste tomatoes later in the year.
Photo Kathryn Simmons
Roma tomatoes in an earlier year, with rolled hay mulch. Photo Twin Oaks
Plentiful harvest of Roma paste tomatoes. Photo Twin Oaks COmmunity

Cautions about no-till planting

  • Cold-hardy cover crops need time in spring to grow to optimal size before mowing – they are not suitable for early spring food crops
  • Untilled soil in spring is colder than tilled soil: growth of anything you plant in it will be slower, and harvests delayed. Not good for warmth-loving crops such as watermelons!
  • The rate of nitrogen release from the cover crop will be slower than from an incorporated cover crop
  • Transplanting into untilled soil is harder work than planting into loose tilled soil
  • The timing of sowing, rolling or mowing and planting is critical. The wrong weather can jinx your plans
  • If the cover crop stand is poor, weeds will germinate – have a Plan B. Usually this will involve tilling, adding compost and then finding another mulch
  • There may be some regrowth of the cover crop, if mowing was too high, irregular or poorly timed. If needed, mow between the crop rows a couple of weeks later
  • There may be more fungal diseases and slugs
  • In arid zones, it is necessary to wet the mulch weekly to release the nutrients. Drip irrigation won’t do that
  • Hand-seeding into untilled soil is tricky – winter snow and ice can leave soil quite compacted. Unsuitable for small seeded, closely-spaced vegetables. Pumpkins and squash can be direct seeded in crimped and rolled (or mowed) winter rye.
  • Initial hopes for no-till cover crops – that it would be possible to grow vegetables organically without ever tilling again – were unrealistically high

No-till tractor equipment

  • For mowing cover crops, we use our hay mower/conditioner rather than our (rotary) bush-hog, as it cuts close to the ground and lays the cover crop down without chopping it into small pieces. This helps it last longer, and be easier to transplant into. Flail-mowers are recommended over lower-speed sickle-bar mowers, which can get tangled with long vetch vines
  • Roll-killing leaves a longer-persisting mulch than mowing, although there may be problems with re-growth. Adding a method of crimping the stems increases the effectiveness. Hairy vetch is harder to kill by rolling than crimson clover.
  • Ron Morse designed a No-Till and Reduced Till Planting Aid, consisting of a heavy coulter and shank assembly with a wavy coulter behind the shank to slice the mulch and leave a 2″-3″ (5-7.3 cm) strip of prepared soil, for planting in a separate operation.
  • Transplanters are available that are designed for use with thick organic mulches.
  • Direct seeding of large-seeded crops is possible using equipment to open a narrow slot deep enough for the seeds. No-till seeders are harder to find: an example has a toolbar planter, 15″ (38 cm) fluted disk blades to cut through the vetch mat, 15″ (38 cm) double disk opener, 12″ (30 cm) cast-iron closing disks, plastic seed pressers and extra weights.

More on no-till

At the Pasa 2022 conference I went to the workshop On-Farm Experience with Organic No-Till, by Sam Malriat from Rodale.

Sam pointed out that no-till methods sequester carbon in the soil, but simply never tilling does not improve the soil. He recommended we not be obsessive about no-till, but move towards reducing tillage. Sometimes shallow tillage can be a good choice, adding value by incorporating organic matter. OM and soil water capacity can be increased enormously by using cover crops, compost or manure, grazing, or a good crop rotation.

You need a very solid, heavy cover crop stand, to provide a thick mulch when terminated. There is a lot of difference in thickness of mulch from rye sown in August and in October. You also need a very competitive cash crop; a successful method of planting into the cover crop residue, and a back-up plan in case something goes wrong. For example, sowing corn into rolled and crimped hairy vetch does not work well, because corn is a heavy feeder and is not very competitive. A better idea is to undersow the corn at V5 or V6 (stages of vegetative growth) with white clover or crimson clover in September (in PA). It’s very important to get good seed to soil contact, and enough moisture. The clover grows after the corn dies. If the clover is left growing into the second year, cabbage can be transplanted into it.

Rye termination timing: When to successfully crimp

“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.”

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

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.

2023-2024 Vegetable Growing Conference Tips 4

 

Alkindus lettuce from High Mowing Seeds

This is the last of my series on tips I learned at sustainable farming conferences the past winter. The sessions reported on here were at PASA.

Harvesting Techniques for Small and Medium Scale Farms

This was presented by Julie Henninger and Andy Russell of Goodkeeper Farm in Gardners, PA. They run a Full Diet CSA, with 7.5 acres of vegetables including five high tunnels and outdoor vegetables, and turkeys, cows and pigs. Their well-organized workshop covered their Top Crops (head lettuce, baby greens, carrots, bunched greens and roots); Pre-Harvest Prep (check list, harvest pouch, rubber bands, sharp knives, bins, other equipment); Techniques; Post-Harvest Work; Pitfalls to Avoid and Meet the Farmers.

For a harvesting pouch they use a nailbag that clips on the waistband, to carry their knives and rubber bands. For harvesting crops, they recommend the Hoss harvest bag. Both leave both hands free for picking.

Hoss Harvesting Satchel leaves hands free.

Goodkeeper Farm practices flaming or tarping to deal with weeds before they become a threat to their crops. All their lettuce is transplanted using a paperpot transplanter. This Japanese designed implement is imported to the US and is now also being made in the US. They favor the red butterhead Alkindus lettuce. See photo above.

For carrots, they grow 6 rows on a 30” bed, spaced as 3 pairs of rows with 2” between the pair. As they harvest the carrots by hand, they broadcast rye, to get the cover crop established as early as possible, and keep live roots in the ground for the most time. They have made a carrot washer from a cement mixer, reducing the size of the belt to slow the machine down. See Root Washers for Produce Farms.

Root Washers for Produce Farms, from University of Vermont Extension Ag Engineering

Top of their tips for techniques is to ensure each person masters the tasks first, limiting distractions. A strong role model demonstrates the technique and the expected pace. After getting those two aspects as second nature, the learner can start to have conversations and other distractions.

In the Pitfalls to Avoid, they list damaging the crops while harvesting, overloading harvest bins, using the wrong harvest gear, failing to invest in good appropriate equipment, dull cutting tools, and actions such as gathering different size bunches, that require re-bunching – try not to need to touch the crops again after harvesting!

Winter Market Gardening

by Catherine Sylvestre, the farm manager at Ferme de Quatre Temps, in Quebec, and co-author (with Jean-Martin Fortier) of the book Winter Market Gardener. Read my review here.

Cover of The Winter Market Gardener

Catherine gave both an introductory presentation and an advanced session with an excellent handout. At their zone 5b teaching farm, they have 27,000 sq ft of sheltered growing: 4 high tunnels, 3 greenhouses and one multi-bay shelter. They offer a two year program for students wanting to learn sustainable farming. They close for a two week break over the winter holidays, and plan their crops to be ready for harvest either side of that break. They need to sow in June for harvests before the break. They have five Principles of Winter Gardening:

  1. Use simple shelters, plastic-covered tunnels, for best profitability
  2. Add minimal heating. By adding 3 Celsius degrees (5.4 F degrees), they double their yields, and avoid using rowcover. Evening out the temperature between day and night reduces stress on the plants. Nutrients are more active if the soil is warmer.
  3. Increase the cold tolerance of the crops. This increases the sugars in the cells, making them more cold-tolerant from then on. Increase the airflow and expose plants to cold temperatures. They start this hardening off at the first frosts, and find that 7-10 days of chilling is needed to create a lasting result.
  4. Be aware that light is the limiting factor (especially for spinach). Their light in November is only one quarter of what they get in August. They plan to grow many crops to size in September and October. Although Asian greens can make some growth Nov-Feb, many crops will not. The ratio depends on your latitude, and is less extreme where we are in Virginia. Grow crops that are less affected by light shortage. Adding artificial lighting is not financially worthwhile.
  5. Well, my notes don’t include #5! It was something to do with appropriate crops, I think. Crops they can grow under shelters with no additional heating: spinach, baby kale, tatsoi, mustards, corn salad (mâche), claytonia, if T19 rowcovers are added for temperatures below 0°C (32°F). They use two layers of rowcover for temperatures below -5°C (23°F) and three layers below -10°C (14°F). They use minimal heating for chard, pak choy, Chinese cabbage, kale, lettuces, turnips, radishes, arugula, sorrel, celery, cilantro, parsley. You could consider soil-heating with PEX tubing filled with glycol (poisonous), 24″ (60 cm) deep in the soil, below cultivation level. At Quatre Temps they use above ground perforated polyethylene tubing in the pathways (it’s OK to step on it, it’s not high pressure).
Tatsoi at Twin Oaks ready for harvesting of whole plants.
Photo Pam Dawling

In the advanced session, we learned more details of their techniques and systems.

  • They start seeds for their winter crops in large cells (4″, 10 cm) so that they can keep their summer crops in the ground for 1-3 weeks longer. When they transplant these, they are careful about spacing, aiming to increase the light falling on each leaf. They plant the crops twice as close in the row, with double-wide spaces between rows, compared to warmer, more light-filled times of year.
  • They irrigate twice a week for 20 minutes, but I don’t know the flow rate of their driptape. From November to January they do not irrigate at all, as growth is so slow.
  • They fertilize in two doses, a little at planting time and more in February, using a mixture of compost, chicken manure and cotton meal, with the addition of feather mela in February. Bacterial activity increase with soil temperature. “Fertilizing cold soils is mysterious. . .”
  • Diseases in winter are mostly fungal. Use strong transplants, with a Rootshield dip before transplanting. They open the sidewalls every 4 hours to remove excess humidity and pay close attention to airflow. If needed, they use Contans.
  • Aphids survive at 5°F (-15°C). At 50°F (10°C) an adult female can create 20 offspring (per day?). At Quatre Temps, they use a three week winter break with no crops to freeze out their shelters. It gets down to -4°C (25°F). They disinfect in spring, removing all plant material, cleaning the structure itself with water and SaniDate (although it also kills beneficials).
  • For heating, a heat pump is very expensive but very efficient. An electric coil is less expensive. A climate battery (aerothermal energy) costs $20,000 and includes 24” (60 cm) diameter pipes deep in the soil, and a large fan. They use one to pre-heat air for the air-tube heating system. Something most of us can only dream about.
  • After the winter break, they direct sow new crops. To provide food for April, they plan gradual crop successions to bridge the gap between winter and spring. This also evens the workload.

Senposai is our star of Asian greens at Twin Oaks. Here’s a bed of senposai outdoors in spring. it grows really well in the winter hoophouse. Photo Kathryn SimmonsCrops they have been trialing include perennial sorrel, which regrows early (mid-Feb); celery and parsley (both very successful winter crops); Tokyo bekana, senposai and komatsuna (grow well in low light); green onions in fall and spring (don’t do well with light levels they get in winter); chrysanthemums regrow well, even in low light.

Book Review: The Barefoot Farmer, Volumes I and II, by Jeff Poppen

The Barefoot Farmer Volume I, 1993-2000

Book Review

The Barefoot Farmer, Volumes I and II. Jeff Poppen, 2001 and 2021, 233 and 221 pages, 6 x 9 inches approximately, with drawings throughout. $20 each or $35 for two, via https://barefootfarmer.com.

The Barefoot Farmer Volume II, 2000-2011

Jeff Poppen at Long Hungry Creek Farm, TN, is a lively and fascinating farmer and writer. Jeff’s style is folksy, lyrical, reverent, amusing, at times whimsical or iconoclastic, and always attentive to what works, what benefits the land, and how to farm better.  No doubt you will heartily agree on some points, and heartily disagree on others! These two small books are compilations of pieces he wrote weekly for his local paper from 1993-2000 and 2000-2011, revised and updated. Jeff is a flexible Biodynamic farmer, who writes for all growers and farmers who care about good food and the long-term future. Jeff’s farming joy spreads wide, with gatherings at his farm, music, TV shows, community events and mentoring young farmers. In addition to these two books, Jeff has written a digest of Agriculture, the teachings of Rudolf Steiner, the founder of Biodynamics.

The articles have been re-arranged by themes, with part of each book on specific aspects of his farming, particular seasons, individual crops, farming past, present and future. The first book starts with the importance of organic matter, compost, and learning from what is happening under our noses and eyes. By watching what a bug does, we may better understand why it’s there and how it relates to the whole local environment. We may learn to make changes in what we do, rather than focusing on eliminating the cause of the holes in the cabbage leaves. Understanding our soil structure will give us appreciation of how the growing and dying of roots improves soil.

Here is an example of Jeff’s humor, realism and humility: “Although I make many tons of compost during the winter feeding of our cattle, it is just not enough. So I’m admitting to an overabundance of idealism and a lack of poop.” He cleans out other people’s barns.

Cover crops increase the canopy of leaves collecting solar energy, transforming it into more plants and then more animals. Mother Nature sends in weeds to cover bare ground. Thomas Jefferson apparently wrote that an acre of buckwheat is worth ten loads of dung. Jeff observed how a field of buckwheat rescued a sweet corn patch. In a dry spring the corn seed did not emerge, so Jeff over-sowed with buckwheat to put some roots in the ground. The buckwheat sprouted with the dew (no rain or irrigation). When the buckwheat reached flowering (still no rain), Jeff noticed the corn had grown, presumably benefitting from the buckwheat roots moving the dew deeper into the soil.

Jeff’s description of broadcasting cover crop seeds is quite poetic, and starts with “I quiet myself.” Many people who have broadcast seeds will recognize the attentive state and loose limbs that are needed to do the job well.

Jeff Poppen Outstanding In His Field

Jeff’s farm became a Community Supported Agriculture farm in 1997, with 32 members paying a monthly fee to receive a box of seasonal produce and opportunities for community events at the farm.

The first book divides crops by season, starting with potatoes in spring, which Jeff chits (pre-sprouts) as we do. By setting the potatoes in flats indoors for a few weeks, the certainty of plant emergence and therefore the yield can be increased, and if the conditions aren’t right on the hoped-for planting date, planting can be postponed, while the potatoes continue to grow. Jeff tried many varieties of potatoes and found that the ones that did best were Kennebecs and Red Pontiac from the local feed store. Funnily enough, we’ve also come down to planting those two, here in central Virginia!

They grow Ebenezer onion sets, knowing they will not store. In the fall, Jeff replants remaining non-storing onions packed in a trench. These provide early green onion tops next year. Onions from seed are started in a coldframe in late September. He plants the bareroot starts out in mid-March. Walla Walla do well for big onions to eat soon, but Copra do best for storage.

With asparagus, Jeff learned the same lesson I did: do not follow instructions to plant new crowns 12″ deep! They will do better 5″ deep. Really!

A week after planting big seeds (potatoes, squash, beans, corn), before seedlings emerge, Jeff runs over the rows with a spike-tooth harrow (large-scale) or rake (small-scale), dispatching tiny weeds without damaging the seeds below the surface. There are many practices like this that we could gainfully employ to reduce our weeding work. When hoeing, observe your plants, and any problems. Squash any pest bugs as you go. Fill gaps in the row from a seed packet in your pocket.

Jeff grows rye and Austrian winter peas for the cover crop preceding winter squash, then in mid-April mows strips down in each place he wants a row, and adds manure. When the squash vines start to run, Jeff mows down more of the cover crop, now flowering, making a no-till mulch right where it’s needed.

Jeff explains the American system of growing some crops on hills, which has always mystified me, an immigrant. He says the root areas dry out more, mimicking the desert conditions they came from. Another reason is helping to locate a large amount of fertility right where these large plants will need it initially. 6-8 seeds are planted in a circle in the center of the 2′ diameter hill, with hills many feet apart.

Jeff describes a sweet potato planting stick made by his neighbor. A stick with a notch in it and an attached wire is used for both pushing the slip down into the soil, and measuring the distance to the next plant. These newspaper articles still contain original comments such as that Jeff has left his surplus sweet potato slips at the feed store for anyone who wants to take some. Later he’ll offer home-grown kale seed, and invite people to leave their bags of leaves at the feed store for him to collect.

The fall garden needs prompt planting. August 4 leaves them 70 days to frost, and is their last chance to sow beans. Cabbages follow their early beans, using the remains of the moisture and compost left by the beans. To ensure the seeds get enough moisture to germinate, he presses them firmly into the soil. He likes to do this by walking heel-to-toe along the row. Yes, he does farm barefoot. And attends conferences barefoot. He wears shoes for tractor work.

Next is a section on putting food by. This includes moving storage crops into more ideal long-term locations, as well as solar drying, canning, jellies, jams, pickles and soups canned in jars. Seed saving follows, including chickpeas (garbanzos) which their local organic gardening club trialed.

Celery is a valuable plant for attracting beneficials if it flowers. In the summer the center of the celery plant dies; we always cut ours out, enabling the side shoots to grow into big plants themselves. I was interested to see that Jeff does as we used to do, moving some large plants into the greenhouse (hoophouse in our case) to supply stalks all winter. Several berry crops are mentioned and I was amused to read that when Jeff asked an orchardist how to keep birds out of his cherry trees, the orchardist replied “Plant mulberries!”

Jeff has done a lot of work with apples, collecting and trying different kinds, and grafting. At the turn of the 20th century there were 6,000 apple varieties (in the US?). Before the turn of the 21st century, we were down to 2,000. Jeff writes about many of his favorites, Lodi, Yellow Transparent, Early Harvest, Little Strawberry, Golden Sweet, Pink Sweet, Grimes Golden (susceptible to cedar-apple rust), Mollie’s Delicious, Liberty (resistant to many diseases including fireblight), Winesaps, King David, Jonagold, Jonagrimes, Gala, Blushing Golden, Rusty Coat, Fuji, Yates, Arkansas Black – all good. Avoid Ben Davis.

Pruning is an important skill (“When do you prune fruit trees? When the pruning shears are sharp”). Jeff avoids winter pruning, apart from removing damaged wood and shaping the tree, and favors May-early June pruning for fruit bud formation. Winter pruning stimulates vegetative growth rather than the formation of fruit buds. When there is plenty of growth happening, fewer fruit buds grow for next year. Jeff has grafting tips too, including that masking tape works well for top grafting.

Volume II includes advice on pears, which are easier than apples to grow without pesticides, if you choose good varieties. Jeff favors Magness, Warren and Maxine, which are resistant to fireblight. Choose a site on a hill, to spill the frosts away, and late-blooming varieties to avoid losing fruit to late spring frosts.

The first book goes beyond the garden into the fields. Jeff is an advocate of integrating livestock into all vegetable production, to improve self-reliance and food quality. Jeff says the annual dropping of manure from one cow can fertilize 4 acres if carefully used, whereas the cow herself only needs two acres of pasture. Cows provide a valuable service, even if you don’t avail yourself of dairy products or meat. Hindus are vegetarians, but may keep cows. Jeff says that ancient wise people forbade the eating of meat, so that cattle, sheep and goats survived the years of famine, keeping the future of their agriculture safe. Rudolph Steiner said that farming is never sustainable without livestock. He proposed that with the proper number of animals, a healthy farm can produce all its own food, feeds and fertilizers.

Jeff gives a brief explanation of Biodynamics and the role of the field sprays, cow horns filled with manure or ground quartz paste, and buried. He makes it clear that fertilizing with horn manure and horn silica do not replace manuring in the usual way. It is vital to continue good farming practices. The six Biodynamic compost preparations, used in tiny amounts in compost and manure piles are thought to radiate living forces and make the compost or manure more effective. It is not necessary to believe this to try it and see what happens. Jeff is on record as saying that when he first learned about the horn manure, he thought it was a load of hogwash. He also noticed that the farms it was used on were wonderfully fertile. He has been using Biodynamic methods (mostly) ever since.

I believe that there are many ways of being a good farmer, and I respect all good farmers. The keys seem to be attentiveness, fantastic memory or good record-keeping, and modifying what you do based on what happened with what you last did.

Jeff writes about planting by the Stars/Zodiac Signs; the fire, earth, air and water elements; and fruit, root, flower and leaf plant parts that correspond in this system. He tries to work with the moon and the planets, but the weather is the determining factor in what they do each day. His approach is that nature is forgiving, and if you plant on the wrong sign, the seeds can sit in the soil until the right sign comes round again. It is probably unscientific to disregard anything, he says.

The second volume opens with the mission statement of their farm: “Our aim is to grow high quality food and help others do the same, and to educate ourselves on how this is most efficiently accomplished.” There are several sections with topics similar to those in volume I. Jeff believes in using a moldboard plow, slowly, in the fall, to open up new fields for gardens. He likes to let the winter weather convert the exposed soil to a friable state. He recognizes that plowing has gone “out of fashion” and that the soil life suffers and must be replenished. He knows when to stop cultivating soil to avoid destroying the structure. He recognizes when he needs to use a subsoiler or a chisel plow (rebreaker) to break up the hardpan that develops.

In volume II, Jeff often writes about his experiences farming without any irrigation, 2000-2011. Compost, mulch, good humus, can help a lot. Here’s a trick Jeff used in a dry summer to get the fall garden to sprout: right after bushhogging the old beans, summer squash and cucumber beds, he made new furrows and sowed seeds. He walked over the rows, pressing in the seeds. The moisture from the shredded plants and the shade of the old plants (now mulch) was enough to germinate the seeds. Before the use of chemical fertilizers, market gardeners added 50-75 tons of composted manure per acre each year, and had a quarter of the garden space in cover crops at any given time. How much compost to use has been much debated in recent years. Are you really seeing damage if you use more than some people recommend? Or are you seeing better growth, higher yields? Paying good attention is key.

Jeff says “I’ve two answers for most garden questions: Either “add more compost” or “I don’t know.”

In another section, Jeff explodes some garden myths, teasing out the threads of truth they contain. Are heirloom seeds always better than hybrids? For some crops, open-pollinated varieties do well. OP, not necessarily heirloom. For other crops, hybrids do better: broccoli, sweet corn, tomatoes, peppers. Let’s appreciate the skill and hard work of plant breeders who have brought us varieties with better disease-resistance, increased productivity, better weather-resistance, and yes, sometimes better flavor. Let’s see what actually grows best in our particular gardens, for our particular needs.

To qualify for Organic certification, compost must reach 150F, but Jeff prefers not to let his compost get hotter than120F, to preserve more of the original microbes. He also prefers not to turn compost as the certificate requires, but to let it sit undisturbed for a year to encourage fungal growth. Organic certification is not always the measure of good practice. It allows use of some fertilizers that can leach in the soil and harm good microbes. It allows some toxic pest control products extracted from plants. (Maybe not as many nowadays as when written in 2009.) Jeff has moved away from Organic certification, as some other farmers have done, because he considers he can do better than Organic.

Crop rotations optimize the use of soil nutrients, because different crop families use them in different proportions, and return them to the soil in different proportions. Jeff’s approach is to alternate not only crop families, but also plants with varied edible parts: roots, leaves, fruits, to prevent the soil becoming sapped of particular nutrients.

When writing about warm weather crops, Jeff claims that tomatoes like to grow in the same spot every year. This I have strong doubts about. Maybe it works in places with few soilborne diseases and pests. Jeff says they have been lucky (up to 1999).

Some plants do better after particular others. Potatoes don’t do so well after carrots, beets or other crops requiring lots of tillage. Heavy nitrogen feeders such as corn, do well after nitrogen-fixing legumes. Big seeds can be sown in rougher soil than tiny seeds. Jeff rotates crops intuitively, considering the big picture. This is perhaps a method best used by experienced growers with knowledge of the big picture, and not so helpful for beginners, or team-run farms.

Similarly, prioritizing tasks for the day, is easier once you have more than a decade of experience under your belt! If it’s going to rain soon, do the tasks impossible after rain. If it ends up not raining, what will you regret not doing? Don’t just choose the job you most like doing. Keep your mission in mind.

Weeds are best controlled before visible! Prepare the bed, leave it a few days, rake shallowly and plant. A few days after planting, if it is dry enough, rake lightly again, right over the seeded bed. With potatoes, the hoeing between planting and emergence can be deeper, and is very worthwhile. With early-sown carrots, take advantage of the period before the carrots germinate to get rid of millions of fast-germinating weeds. Develop good hoeing posture, keeping your back straight, hinging at the hips, and switching sides back and forth. Don’t get very good at hoeing only to your best side! Jeff paces himself, dividing the length that needs hoeing by the time that seems reasonable. It’s more important to get to the end, doing an 80% perfect job, than to hoe only part of the row, leaving the rest to grow bigger weeds. He reckons on 10 feet per minute. The 80/20 Pareto Principle guides much of his work: “In my life, 20% of the weeds are ignored, 20% of the blueberries are left unpicked, 20% of the grass is unmown, and 20% of my life is a mess. But my cup is 80% full.”

It’s worth pulling up pigweeds that miss the hoeing. Millions of pigweed-loving microbes die and become food for the crops. But if the pigweed continues to grow, pigweed-loving microbes multiply and more pigweed seeds germinate.

The later chapters of volume II are about livestock, pasture and hay, and biodynamics. Not being a biodynamic or livestock farmer myself, I paid less attention to these chapters.

Barefoot Biodynamics by Jeff Poppen April 2024

Jeff has another book coming out in April: Barefoot Biodynamics.

He also has some YouTubes, see https://www.youtube.com/watch?v=msKw7rrfHJo

 

2023-2024 Conference Tips 3 – Climate Change, less usual edible plants

Carrots under shade cloth in summer.
Photo Pam Dawling

2023-2024 Conference Tips Part 3 – Climate Change, Less Usual Edible Plants

I reported earlier on good tips I got from the CFSA Conference and the VABF-SFOP Summit.  Here I’ll continue the theme.

At the VABF-SFOP Summit, I also attended workshops on Meeting the Climate Challenge with Mark Schonbeck, and Eating and Marketing the Whole Plant with Chris Smith. I’ll tell you more about those now, then move on to the Pasa Sustainable Agriculture Conference.

Meeting the Climate Challenge: Sharing Stories, Co-Creating Solutions with Mark Schonbeck

Mark’s slides and handout will be available soon on the VABF website. In our region we are experiencing hotter summer nights, which are hard on plants (and livestock, I’m sure). At 95F (35C) most crops close down completely or slow their growth. For every 1.8F (1C) in warming, 3-10% of the Organic Matter is lost (burned up) and nitrous oxide emissions may increase 18-28%. Daffodils are flowering up to 5 weeks earlier, fruit trees are budding out earlier, risking losing the fruit to freezing nights. In the spring we are getting later cold snaps below 10F (-12C) in March.

We are having a longer frost-free period, with more generations of bugs. Downy mildew of cucurbits is spreading further north than previously.

Our kale beds after heavy rain. Photo Wren Vile

In Virginia we are getting more intense and heavier rains, with more flooding. The erratic nature of the rains means we can experience flash floods, followed by droughts and wildfires. Heavy rainfall leads plants to grow shallower roots, which then die if a sudden drought follows.

Keeping living roots in the soil will increase climate resilience, as will other ways of building healthy soils, such as diversified rotations, and varied agricultural enterprises. Here’s Mark’s list of

6 Organic Principles of Soil Health:

  1. Keep the soil covered
  2. Maintain living roots
  3. Return organic residues to the soil
  4. Minimize soil disturbance
  5. Diversify crops
  6. Integrate livestock.
Teff cover crop.
Photo Wikipedia

Increasing the use of cover crops will help with 1, 2, 3 and 5. Teff can be considered as a summer cover crop in alleys between plastic mulched beds. Mixing with clover gives better soil coverage. I have not yet tried this myself. Oats/barley/peas/mustard sown in March will grow big by June, adding lots of biomass. Oats/radish/legume cover crop mix will winter-kill. Silage tarps and landscape fabrics can help hold the soil in place.

Installing terraces, berms and swales will help with water management. Installing drip irrigation will help manage droughts. Protected growing, in hoophouses or caterpillar tunnels, will help protect from many kinds of extreme weather. There are steps we can take to mitigate climate change, and more information is becoming available.

Eating and Marketing the Whole Plant with Chris Smith

Chris is the author of The Whole Okra, and part of his presentation was about the many uses of okra, beyond cooking the pods. Okra leaf chips are the latest thing he has tried. The leaves are used for soup in Nigeria. The flowers can be eaten or dried for tea. The oil from okra seeds is nutty, citrusy, a bit like olive oil, although the yield is small, at 9-20%. The oil presscake can be ground for defatted flour.

Book Edible Leaves of the Tropics by Franklin Martin, Ruth Ruberte and Laura S Meitzner

Chris showed us a remarkable book Edible Leaves of the Tropics, by Franklin Martin, Ruth Ruberte and Laura S Meitzner. Plants for a Future  has a database of 8000 plants, including edible plants.  The Book of Greens by Jenn Louis and Legume Species as Leafy Vegetables by Robert P Barrett (online) are also valuable resources on edible plants.

DIYseeds.org educational films on seed production

Go to https://www.diyseeds.org  then search for info on growing seeds.

Male squash flowers can sell at $1/flower for an 8-week season. Winter squash yields can increase if some of the early male flowers are removed! Wisteria, redbud and black locust flowers are edible. Kudzu offers many food options (eat it up!) Roots of dandelion, burdock, thistle, sassafras, daylily, dahlia, runner bean and chayote are all edible.

Soil Health, Climate Adaptation and Mitigation Planning, Rachel Schattman, Sara Keleman and Nic Cook

In February 2024, I participated in the Pasa Sustainable Agriculture Conference.  The first session I attended there was Soil Health, Climate Adaptation and Mitigation Planning, with speakers from the University of Maine Climate Science department. They reported that the NE has seen a 15% increase in Growing Degree Days since 1948, and the frost-free growing season in Maine has increased by 14 days since 1895. California has seen a 40-50 day increase in that period. In Maine the temperature changes are greater in winter than in summer. Since 2012, half of the US has shifted to the next warmer winter-hardiness zone. It is helpful to watch indicator species to determine when to plant particular crops. (See my post on Phenology). Warmer temperatures mean that the air holds more water (7% more for each C degree). This means slower storms, more storms heavier rainfall. They also experience droughts, and distinguish between agricultural drought, meteorological drought, and hydrologic drought – be sure which kind your conversations are about.

Young blueberry plant in snow. Photo Bridget Aleshire

Sea level rise is dramatic on the East coast because of past glaciation. The other main impacts they are seeing on agriculture include False Spring (fruit bud kill after a “warm snap”), winter soil erosion and rain ponding, and new pests, diseases and invasive species, warm season heat stress including crop quality deterioration, greater irrigation demands and needs for shade and ventilation (drought can decrease yields 30%), storm intensity including hail and high winds, longer power outages, soil compaction and nutrient runoff, increased rainfall leading to delayed planting and crop losses. These are all possibilities to prepare for. The silver lining is that there may be new crops we can grow, or longer seasons of familiar crops. NRCS, Extension and other resources are available. Climate-Smart Farming and Marketing is a program for farmers from Maine to South Carolina, offering financial support and technical help to farmers implementing climate-smart practices such as cover cropping, agroforestry, reduced tillage and prescribed grazing.

Prescribed grazing is the intentional use of ruminant animals (hoofed herbivores such as cows, sheep, and goats) on the landscape. Unlike conventional grazing, prescribed grazing utilizes a grazing plan that dictates the location and duration of graze periods. This plan is informed by the ecology of the grazing area.” (Community Environmental Council).

Garlic beds next to rowcovered broccoli beds, under a stormy sky.
Photo Wren Vile

We were helped through an 8-stage planning process:

  1. Risk Assessment (prioritizing which aspect of climate change to deal with first). Heavier rains, then high temperatures, wildfire and smoke, plant diseases.
  2. Vulnerability (looking at your system, climate, location, and seasonal time period). Consider both Exposure to the risk and your farm’s Adaptive Capacity.
  3. Option ID. Consider all of small, medium large and total transformation of your farming. Divide your options up into 4 quadrants on axes of cheap-expensive, difficult-easy; low Greenhouse Gas-high GHG, reducing risk-increasing risk; low impact-high impact, quick to install-takes a long time.
  4. Evaluate tradeoffs (financial, ecological, social). Rank your options and select one that meets as many of your priorities as possible.
  5. Try to meet several goals with one solution. Consider seeking advice or funding.
  6. Monitoring and assessment. How will you measure the improvements?
  7. Revising/tweaking. Reflect and assess. Consider success at each stage.
  8. Share what you learned. Don’t expect perfection, or that others will expect that from you.

Next followed a section on funding. Currently there is lots in Inflation Reduction Act coffers for efficiency increases, renewable energy, conservation practices. Try REAP (Rural Energy for America Program), USDA, NRCS, Rural Development Office for your state, SARE funding for experimentation and trials, state agriculture departments, advocacy organizations, regional non-profits, Chesapeake Bay Trust, Farmer Resource Network, county grants, Beginner Farmer grants, grants for historically under-served farmers, Ambrook Accounting software for American farms..

Take a buddy with you to the offices!

Farmer Resource Network

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!