Tag: cover crops

Book Review: The Self-Fed Farm and Garden, Eliot Coleman. Chelsea Green. November 2025. 208 pages, $29.95 USD, $40.00 CAN

Eliot Coleman has been one of my vegetable-growing gurus since he wrote The New Organic Grower in 1989, and his latest book, The Self-Fed Farm and Garden, confirms our alignment once again. Biologically based agriculture can create and maintain lasting soil fertility by relying on ancient peasant knowledge about the importance of returning organic wastes to the soil. It is time to focus on maintaining soil fertility by farm-grown systems in a clean, safe, self-contained method of production.

Eliot’s book is a valuable contribution to the Real Organic movement, a return to the less industrial roots of growing healthy food. Aim to keep every bed filled with a seasonal vegetable, fruit or a productive green manure crop. Organic farming is an embrace of the soil’s biological systems, not a focus on rejecting chemicals. It is not necessary or wise to import organic waste materials from elsewhere (probably to the deprivation of the land they came from).

Here are clear, concise descriptions of systems for developing and maintaining rich soil that will sustain itself over the long-term, using incorporation of green manures by shallow tilling, adding nitrogen to the soil by growing legumes, and using a crop rotation system to manage pests, weeds and the distribution of nutrients. As there are almost no purchased imports, this method is accessible to farmers everywhere, who have little money but a commitment to pay attention to their soil.

A self-sustaining system with no imported additions to the soil avoids risks of introducing incidental pollutants to your farm, such as PFAS from sewage sludge. Purchased composts and manures can contain pesticides, herbicides, heavy metals, antibiotics, hormones, and other veterinary medications. The only sure way to have clean and fertile soil is to grow your own organic matter right on the farm. A direct outcome of organic soil care is the production of crops with active immune systems, resisting pests and diseases.

Eliot distinguishes between green manures sown for the purpose of incorporating into the soil, and cover crops grown to scavenge soluble nutrients from the soil and protect the soil from erosion. The latter are cut and left on the surface, and do not provide as many nutrients as those incorporated. These groups overlap, and both are components of self-fed farm systems. I tend to call them all “cover crops”.

The Self-Fed Farm and Garden includes many quotes from earlier organic farming writers. In 1908, Liberty Hyde Bailey said, “Every well-managed soil should grow richer rather than poorer; and, speaking broadly, the farm should have within itself the power of perpetuating itself.”

Leonard Wickenden, in Gardening with Nature in 1954, addressed the claim that if you are selling products off the farm, you will exhaust the soil if you don’t deliberately replace the nutrients you remove. Wickenden pointed out that annual additions to replace a particular nutrient removed by a crop will likely only make a tiny change to the vast amount in the soil. Wickenden said: “Let your aim be to feed your soil – not your plants.” The soil is not an inert medium for moving nutrients to the crop. Feeding the soil with organic matter leads to “a process of day-by-day nourishment which will produce sturdy vigor in the crop.” As the OM decays, it adds many nutrients, including minerals pulled from the soil into solution by acids that develop.

Adrian Pieters in his book Green Manuring (1927) suggested that green manures alone might not be enough to maintain organic matter long term. However, it has become apparent that once a vigorous soil biology is established, it is possible to maintain soil fertility with very small inputs. One purchased mineral you might need is boron. (Granubor is made in the USA and every batch is traceable to its source.)  Another is local rock dusts, which need more research.

Alexis Carrel, in his book Man, the Unknown (1935), made this important point: “Chemical fertilizers, by increasing the abundance of the crops without replacing all the exhausted elements of the soil, have indirectly contributed to change the nutritive value of cereal grains and vegetables.” By “change”, he means “decrease”!

Eliot points out that his system of including a rye and vetch mixture on one-third of their land answers this concern. Sown in October, it is mown and shredded in mid-August, allowing the self-sown mature seed to grow for the second cover crop year.  The following April it provides a large mass of high-lignin residues to increase the total soil OM. The root system of this crop is huge, and the fresh green growth is tilled under and allowed to decompose for three weeks before planting vegetables. Every grower can design a green manure combination and sequence suiting their land and climate. Experimentation and careful monitoring will help determine the best choices.

One handful of fertile soil is thought to hold many more living creatures than there are humans on Earth. The whole farm can be considered a living organism. Biologically self-sufficient organic farming or gardening will maximize the health of the whole farm. When he began farming, in New Hampshire, Eliot received gifts of piles of rotted horse and chicken manure and granite dust waste. These additions helped him grow magnificent crops from the beginning. Eliot acknowledges that his farm was not self-sufficient from day one, and he lists seven related questions, including how long his initial inputs would be enough to feed the soil, and whether a food producer could create and then maintain fertile soil entirely from internal systems. To test out this latter idea, he has set aside two acres to see how long it takes to bring the fertility of that patch of soil up to the standards of the rest of the farm, using a dedicated green manure program.

Organic farming books of the 1960s used to focus on listing which organically acceptable soil amendments could be used as substitutes for bagged NPK, and organic gardening magazines in Eliot’s early years of farming were kept afloat by advertisements for organic products. Those products make profits for the manufacturing companies, not for the grower. Eliot says the focus on purchased inputs gave the impression that this is the main foundation of organic farming, ignoring the vital practices and methods of maintaining a healthy soil. Take care of the soil and the plants by using sustainable methods, not by substituting USDA Organic-labelled products for industrial chemical fertilizers and pesticides! It is time to refocus on organic techniques, as Real Organic is doing. Organic Matter is the vital amendment to continue to focus on every year, to prevent soil exhaustion, not minerals.

Shallow incorporation of crop residues and green manures helps provide a secure food supply, without need of purchased compost or manure. The Self-Fed farm is not a No-Till farm. Edward Faulkner, author of Plowman’s Folly, often hailed as the parent of no-till, was not opposed to tillage, but to the moldboard plow in particular. His later book, A Second Look, advocates for shallow incorporation of residues and green manures, to maintain soil fertility.

I encourage No-Till farmers and gardeners to read The Self-Fed Farm, and consider the pros and cons of each system, or more precisely, the situations where no-till is appropriate and those where shallow incorporation of green manures provides the best for the soil.

European farmers settling in North America practiced a kind of soil-mining, extracting crops without consideration of the future. Once yields became too low, they moved west and repeated the process. Fertilizer inputs from Peruvian bat guano from the 1830s led the shift towards bought-in inputs, a one-way transfer of materials from a source to the farm. When the guano deposits were completely exhausted, the chemical fertilizer industry began to grow.

In England in 1843, superphosphate started to be manufactured, by treating bones with sulfuric acid, rendering the phosphorus very accessible. Previously bones had been steamed and ground to make their nutrients more accessible.

Another popular purchased chemical fertilizer was Chilean nitrate, from the Atacama. This was a further shift towards substitution of a purchased product for a process performed on site by the farmers themselves, growing leguminous green manures to use the nitrogen in the air to feed the soil and crops.

In the early 20^th century, the Clifton Park System of Farming was written up by Robert Elliot, to help other farmers successfully maintain perpetual soil fertility without purchased inputs. The sequence involves rotating crops and pastured livestock: 4 years grazing on deep-rooted grasses and legumes, 4 years using the tilled pasture to grow annual grains on half, beans and vegetables on the other half. This system is called ley farming.

USDA Organic Certification has moved from an understanding of the relation between soil quality and food quality, to a box-checking business that wiggles around Organic restrictions. Now hydroponics, and compost made with effluent from Concentrated Animal Feeding Operations can be included under the USDA Organic umbrella. Fertile soil is a cornerstone of organic farming, but hydroponics uses NO soil! Traditional organic farmers knew that crops grown in water or an inert medium provided with liquid fertilizers would lack some nutrients. “Organic hydroponics” are a fraud, requiring many inputs and large amounts of energy for lighting, pumps and filters.

While I admire the extensive research Eliot has done into traditional European farming practices, I find myself wondering about all the invisible female European vegetable growers, all the vegetable growers in other continents and other cultures, while not dismissing the research provided here. A person can only spend so much time on research, I get that. And Eliot has been a leader in not only research and production, but also education via his books, and workshops.

When Eliot and family began at their Maine farm, they cleared spruce and fir trees, opening up a sandy soil with a very acidic pH of 4.3. For several years they added limestone at 1 ton per acre to raise the pH to 6.0-7.0, more suitable for vegetables and bacterial life. Since then, they have only needed to add small amounts of limestone from time to time. I found similar results on our farm in central Virginia – after a few years of adjusting the pH, the soil has rarely needed more lime.

My heart was warmed to see the title of chapter 4: In Defense of Intelligent Tillage, as I am one of those growers who has questioned the Never Till philosophy and welcomed the “till when you really need to” approach. I saw the damage that “Till often to control the weeds” did to the soil, beating up the soil particles, destroying some soil life and speeding up the combustion of the organic matter by adding so much air. To achieve the benefits of incorporating green materials into the soil, it is necessary to mix them into the top 4” (10cm), where the roots of the young plants will be. Cutting and dropping cover crops on the surface is useful, but incorporating them feeds microbes and larger organisms, which then produce more stable soil aggregates and a better-functioning soil. For the benefits of green manures to outweigh the downsides of tillage, a large biomass of green material is needed.

A 2007 study at ARS Beltsville, Maryland, showed that organic farming’s use of manure and green manures can build soil OM quicker than chemical no-till farming. The result took several years to become clear. Pasa’s Soil Benchmark Study, measuring physical and biological soil health, showed that tilling for weed control and bed preparation on an organic farm was not detrimental compared with no-till. Both methods can work on organic farms.

The third example given is the Rodale Institute, which had very strict no-till rules for farms to be accepted under their Regenerative Organic Certification program started in 2017. Few organic vegetable farms could meet those standards, causing the Rodale Institute to take stock and change the rules. Now soil disturbance is allowed to incorporate crop residues and green manures, control weeds, prepare beds for planting, break up compacted soil or improve drainage.

The fourth example is in The Soil and the Microbe, (1931) by Waksman and Starkey, where the age at which the crop is incorporated in the soil is considered. Younger crops with low C:N ratios decompose more quickly and provide more nitrogen, compared with mature green manures with higher C:N ratios that decompose more slowly. These add more long-lasting OM due to the fiber and lignin they contain.

Eliot is thoughtful in his considerations, just as he was in comparing the ecological costs of plastic greenhouse coverings in his earlier books. Here we look at the fuel needed to do the tilling. Not mentioned are the ecological costs of large plastic tarps used by many no-till farmers to kill weeds and crop residues in organic no-till farming.

There is an appendix of green manures, when to sow them, when to incorporate and which crops could follow. This is a model of how to design a system for a self-fed farm or garden in Maine, or elsewhere when modified. In zone 7a, I would avoid ryegrass, for instance, as it quickly becomes an invasive weed.

This book contains many useful tips on growing cover crops/green manures, even if you are farming far from Maine. Winter-killed green manures in Miane include bell beans, annual alfalfa, buckwheat, forage radish, peas and oats. These can sometimes be raked aside to plant early crops without tilling. Those surviving the winters there include forage chicory, rye, hairy vetch, and red clover. Once you know your lowest winter temperature, you can determine which cover crops to grow over the winter. Climate chaos has made winter-kill of oats uncertain in cold-hardiness zone 7a.

Pay attention to fall sowing dates of cover crops. A Washington State University study of mustard found that an August 13 sowing provided bountiful biomass, a September 3 sowing provided very little, and a September 10 provided nothing worthwhile. As days get shorter and colder, the number of days to maturity of a crop increases rapidly. Don’t delay! But don’t plant too early, as this can lead to cover crops setting viable seed before winter. In central Virginia we know not to sow winter rye in August for this reason.

Some green manure crops can be sown (broadcast or drilled with a small push seeder) while a vegetable crop is in place, to succeed them once the food crop is finished. This increases productivity and reduces tilling. Eliot sows sweet clover under established winter squash plants. Undersowing is time-sensitive and worth experimenting with several times to get best results. Generally undersowing green manures 3-4 weeks after the food crop is planted is about right. Cultivate to remove weeds, then sow the cover crop right away.

Chapter Six provides more information on specific green manures. Cereal rye and hairy vetch (4:1 ratio); field peas and oats sown August 15-September 7 to winter-kill in January; bell beans (small fava beans) drilled in late summer along with broadcast oats, to be winter-killed; buckwheat during the frost-free period, ending 4 weeks before the expected first frost (to be winter-killed); forage radish sown in fall to be winter-killed and suppress nematodes before a tomato crop the next year; Mighty Mustard (Brassica juncea) sown as a soil biofumigant for a pasture being tilled under to grow vegetables; red clover with ryegrass (1:1) for a quick green manure anywhere; forage chicory (or Belgian endive); spinach crop residues before peppers; sweet corn (undersown with soybeans) before potatoes.

Insects and diseases on the crops are indicators of unideal growing conditions. Using pesticides is shooting the messenger and ignoring the message. Many bad things can be avoided by growers paying attention and supplying what the soil needs. But I still believe that bad things can happen to good people.

At Four Season Farm, 40-50 different vegetable crops were grown, belonging to ten botanical families. Crop rotations are designed to avoid growing the same or a closely related crop in the same place in successive years. Green manures need consideration too, in rotation planning. At Four Season Farm, the 3 acres are divided into 75 plots 30’ x 50’ (9.1m x 15.2m). Fall harvest crops are growing in 25 of those, followed by the rye and vetch biomass green manure.

Seven of the remaining 50 plots are covered by 7 moveable high tunnels, with their “partner” plots growing a green manure as soil regeneration in preparation for being covered by the high tunnel next. The remaining plots are subdivided into eight 30” (76cm) beds with 12” (30cm) paths. Ideally the groups of eight beds are planted up at the same time for efficient management. After harvest those beds get the residues incorporated and a green manure is sown two weeks later. The goal is always to minimize the amount of time with nothing growing. Green manures between food crops in the rotation are chosen to fit the length of the gap and the time of year, as well as the preceding and following food crops.

Adding 4-legged livestock can provide safe manure (and milk and/or meat), but can complicate your life a lot, if good organic animal feed is important to you.

Converting crop residues and weeds into compost makes another excellent soil-improver, and by making it yourself, you learn what works and what doesn’t. Compost-making can require a lot of work, and not all growers find it worthwhile.  Eliot makes compost in small amounts with residues that can’t be directly tilled in. Are the compost microorganisms different enough to make the process worthwhile? This is not the place for that debate. The answer may depend on how long you have been farming that land, how long your growing season is, whether you have byproducts from any value-added foods you sell, and how many green manure crops you manage to include each year. I am a believer in compost, but my situation is not identical to Eliot’s.

You may find, as Eliot did, that increasing your crop area by 20% enables you to include more green manures in your rotation and reduce the stress of fast turn-arounds, which are becoming harder as the climate becomes less predictable. The book includes tips on growing successful green manures, and also a section for adapting the info in the book to home gardens.

Eliot and his wife Barbara are resuscitating their 50’ x 50’ (15.2m x 15.2m) home garden, divided in half. One half will grow vegetables each year (with buckwheat as green manure in intervals between following vegetable crops) and the other half a grass-legume pasture. They plan to mow the buckwheat high before 20% is in bloom.

On his 86^th birthday, in 2024, Eliot and Barbara retired from daily market farming and leased Four Season Farm to younger farmers.