Vegetable Storage Tips

Our winter squash storage cage. Photo Twin Oaks Community

Key factors to consider when selecting vegetables for long-term storage

  • Most storable vegetables are roots or tubers.
  • Winter squash, onions and garlic are the main exceptions.
  • And tree fruits such as apples and pears.
  • There are hard-headed storage cabbages too, but those varieties are getting harder to find, as fewer people grow for storage. Search the seed catalogs for the word “storage”. Other varieties are for fresh market, or processing, and won’t store for long.
  • Don’t plan to grow a specific crop unless you have the right kind of place to store it!
  • You also need a likely market. I love celeriac, but it’s not widely known, so I wouldn’t recommend growing lots until you have an idea of the demand.
  • Choose varieties that are sturdy and chunky, not slender carrots, for instance. (Shriveling is related to the ratio of volume to surface area.)
  • Ideally, practice that variety on a small scale the year before growing a very large amount, to see how it does in your soil.
  • If it’s too late to do that, try three different varieties and keep records of how they do.
  • Read the small print in the seed catalogs! Moschata winter squashes such as butternuts. Long Island Cheese and Seminole store all winter, but acorn squash do not. You can store acorn squash for a couple of months, but then move them along to people’s dinner plates.

Harvesting tips to maximize the storage life of stored vegetables

Carrot harvest cart
Photo Mari Korsbrekke
  • Storing vegetables is very much a Garbage In-Garbage Out type of thing. If you put unsound vegetables into storage, they will rot and the rot could spread.
  • Good storability starts with good growing techniques
  • During growth, fend off any serious pest predation, as crops with holes in may not store well.
  • Be sure you know the temperature at which each crop will suffer cold damage, and get it harvested before that happens.
  • Harvest when the crops are optimum size and in peak condition.
  • Ideally, harvest in dry weather.
  • Handle the vegetables gently. Bruises can happen invisibly, so if you drop something, don’t store it.
  • White potatoes can reach a storable state two weeks after the tops die in the field. If you are in a hurry, mow the tops off, then wait two weeks. Check that the skins are “set” and don’t tear, if you rub the potato with your thumb.

    Sweet potato harvest crates
    Photo Nina Gentle
  • Trim leafy tops from root vegetables, leaving very short stems on beets and carrots. During long storage, the stubs of the leaf stems may die and drop off, but this is nothing to worry about.
  • If you cut the tops off beets completely, the red color will wash out during cooking. Definitely don’t cut into the root part of beets when trimming. Some people trim the long ends of beet roots, but I never have. They don’t take up much space!
  • I do trim the roots from kohrabi, and for that task, I do cut into the bulbous part of the root, as the skinny root has such a high concentration of fibers that it’s like a steel cable! The cut surface soon heals over.
  • Look each vegetable over and only store ones without soft spots or deep holes. Carrots or sweet potatoes snapped in half can heal over and store just fine, but stabbed potatoes won’t. Superficial bug bites will heal over but not tunneling.
  • Small roots won’t store well. We have a “training tool” for new crew members which is a bucket lid with holes cut in it. If the carrot can pass through the carrot hole, it’s too thin to store well. Potatoes less than about an inch are not worth storing. Likewise tiny turnips.

    Bucket lid with holes for sorting root vegetables for storage.
    Photo Wren Vile
  • For traditional storage without refrigeration, most roots store best unwashed (less wrinkling). This can make them harder to clean later.
  • If you are going to store root crops unwashed, consider setting them in a single layer on the field and making a second trip round to pick them up into crates when the skins are dry. If you are going to wash them, the opposite is true! Get them into water before the skins dry, to help the washing go quicker. We don’t wash sweet potatoes, white potatoes or squash. We do wash all the other root crops, as it’s harder to get them really clean if the soil dries on them. Provided you store them in humid enough conditions, they will not shrivel.
  • Some crops need curing before storing (alliums, peanuts, sweet potatoes, white potatoes).
  • Tops of garlic and onions can be trimmed after the crops have cured and the leaves died. Making braids or ropes of alliums with their tops on can be a profitable option.

The best storage conditions for different types of vegetables

Crates of potatoes in our root cellar.
Photo Nina Gentle
  • In my book, Sustainable Market Farming, I have a whole chapter on Winter Vegetable Storage.
  • Growers have only good things to say about the CoolBot system from Store-It-Cold. Basically you build a well-insulated space (shed, room, truck body), buy a window AC unit and the CoolBot and follow their excellent instructions to install the device which lets you run the AC at a lower temperature, like a refrigerator, at a fraction of the cost.
  • Hang a thermometer in your storage spaces, so you know when to warm or cool them. Digital thermometers might measure humidity too.
  • You can get a small electronic device that will send an alert to your phone if the temperature goes too far out of range.
  • For storing white potatoes without refrigerators, the best place is a root cellar. You are aiming for cool and moist conditions: 40-50°F (5-10°C), with 85-90% humidity. You really don’t want to store potatoes below that range, or they go black when you make fries.
  • Most other vegetables fit into four other sets of storage conditions:

A. Cold and Moist (33-40°F/1-4°C, 95-100% humidity, works for most root crops, and also cabbage, Chinese cabbage, kohlrabi and leeks.

B. Cool and Moist is mostly potatoes, as I already mentioned. Pears, apples and cabbage also store well in these conditions but not sharing space with potatoes! More on that later.

C. Cool and Dry is for garlic and onions. 32-40°F/0-4°C and 60-70% humidity. It’s also possible to store alliums warm and dry at first, 65-85°F/18-30°C, but definitely not 40-56°F (4-13°C) for garlic, or 45-55°F (7-13°C) for bulb onions or they will sprout. Never warm after cold either.

D. Warm and Dry to Fairly Moist is for winter squash and sweet potatoes. Never below 50°F (10°C). Ideal temperature 55-59°F (13-15°C). Temperatures above 65°F (18°C) hasten sprouting. Also ripening green tomatoes like 55-70F/13-21C and moist (75-85%).

  • For the warmer options, barns or basements might be suitable in the fall, before they get too cold.
  • If you are planning a new barn, consider installing an insulated basement to be a root cellar.
  • There are traditional in-ground storage methods, such as clamps, pits and trenches. The easiest version of this, in the right climate, is to mulch heavily with about 12″ (30 cm) of insulation (such as straw, dry leaves, chopped corn stalks, or wood shavings) over the row, and maybe add low tunnels over the mulch.

    In-ground vegetable storage Drawing from WSU
  • Clamps are made by setting down a layer of insulation on the ground, piling up the crops in a rounded cone or ridge shape, covering thickly with straw, then working round the mound digging a ditch and slapping the soil up on the mound.
Vegetable storage clamp.
Drawing from WSU
  • Pits and trenches start by digging a hole, lining it with straw or an old chest freezer, layering in the vegetables with straw and covering with boards and a thick layer of insulation. Insulated boxes stored in unheated areas need 6-8″ (15-20 cm) of insulation on the bottom, sides, and top.
  • This all takes a lot of work, so look into the CoolBot idea first!

Suitable containers for storing vegetables

  • We use perforated clear plastic sacks for roots, cabbages and kohlrabi. They reduce the water losses that lead to wrinkling.;
  • We use net bags for onions and garlic; plastic milk crates for potatoes;
  • We use folding plastic crates for squash and sweet potatoes.
  • We leave horseradish, Jerusalem artichokes and leeks in the ground here in zone 7a, but we don’t get frozen soil for much of the winter.
  • We don’t use any packaging materials, but in England in the past I stored roots in boxes of damp peat moss, sawdust, sand or wood ash. I find it better to get the right storage conditions for the vegetables, rather than try to insulate them in their crates.
  • Set the containers on pallets, not directly on concrete floors, to reduce condensation.
  • When stacking your containers, allow gaps along the walls and between stacks, for airflow. Celeriac needs more ventilation than beets or kohlrabi, for instance.
  • Sometimes night ventilation offers cooler drier air than you can get in the daytime.

Vegetables that have particular needs for long-term storage

Sweet Potatoes in storage.
Photo Pam Dawling
  • Sweet potatoes must be cured before storage. This means hot humid conditions until the skins don’t rub off when you rub two together. After that you can move them to storage conditions (or turn down the heater and humidifier!)
  • It is important that sweet potatoes never go below 50°F (10°C) or they will suffer a permanent chilling injury that makes them almost impossible to cook. I know because I’ve made that mistake, leaving them in the ground too long, hoping they’d grow bigger.
  • White potatoes also need to cure until the skins toughen, in moist air (90% humidity) for 1-2 weeks at 60-75°F (15-24°C). Wounds in the skin will not heal below 50°F (10°C).
  • We sort our potatoes after two weeks of curing and find that sorting at this point usually reduces the chance of rot so that we don’t need to sort again.
  • They need to stay moist so they don’t wrinkle. They have fairly exacting temperature requirements so they don’t sprout.
  • Remember to keep white potatoes in the dark while curing as well as during storage.
Home vegetable storage options, from WSU
  • Some vegetables exude ethylene in storage: fruits, damaged produce, sprouting vegetables. Some crops are not much affected by ethylene (greens for example) and can be stored in the same space with ripening tomatoes, for instance.
  • Other vegetables are very sensitive to ethylene, and will deteriorate in a high-ethylene environment. Potatoes will sprout, ripe fruits will go over the top, carrots lose their sweetness and become bitter.
  • When storing ripe fruit, ventilate with fresh air frequently, maybe even daily, to reduce the rate of over-ripening and rotting.
  • Ethylene also hastens the opening of flower buds and the senescence of open flowers.
  • Alliums like it drier than most crops. Heed my warning about the “danger zone” sprouting temperatures. Not 40-56°F (4-13°C) for garlic, or 45-55°F (7-13°C) for bulb onions or they will sprout.

Tips for extending the storage life of vegetables

  • For non-refrigerated storage, unless using outdoor pits or clamps, several smaller containers of each crop are often a safer bet than one giant one, in case rot sets in.
  • For crops that store best at 32°F (0°C), if you can only store them in warmer temperatures (up to 50°F/10°C), provided they do have high humidity, you can expect to get about half the storage life they’d last for in ideal conditions.
  • After you’ve put your produce into storage, don’t completely forget about it! Keep a record of what is stored where and perhaps a check sheet for inspection. Monitor the rate of use and notice if you’d benefit from more or less of each crop next winter.
  • Regularly check the storage conditions are still meeting your goal, and check thorough the crops at least once a month, removing the bad ones. Shallow crates make this easier.
  • For root crops and squash, and maybe alliums, the initial storage period is the most likely to show up trouble. Later the crops become more dormant and less change happens.
  • Keeping root cellar temperatures within a narrow range takes human intervention, or sophisticated thermostats and vents.
  • If needed, electric fans can be used to force air through a building.
  • Make a realistic assessment of how long your crop will last in the actual conditions you are providing, and plan to move them all on before then.
  • You may be able to reallocate crops to some colder spaces as some of the original produce stored there gets used.
  • After long storage, some vegetables look less than delicious, and benefit from a bit of attention before the diners get them. Cabbages can have the outer leaves removed, and can then be greened up by exposing to light for a week at 50°F (10°C). This isn’t just cosmetic – the vitamin C content increases ten-fold. Carrots can lose their sweetness over time, unless frequently exposed to fresh air, by ventilating well.
Storage #4 green cabbage. The name says it all.
Fedco Seeds

Book Review The Ecological Farm by Helen Atthowe

Front cover of The Ecological Farm

 The Ecological Farm: A Minimalist No-Till, No-Spray, Selective Weeding, Grow-Your-Own-Fertilizer System of Organic Agriculture, Helen Atthowe, Chelsea Green Publishing, 2023. 368 pages, $44.95.

 In this inspiring book, Helen Atthowe explains her 35 years of experience farming fruit and vegetables in Montana, California and Oregon. This book will appeal to all those (especially orchardists) who are fine-tuning their land management. I think beginners could find it over-whelming, unless they take it in rich small doses! This is definitely a book to dip into and come back to as needed. It provides a Big Picture of ecological farming, not a step-by-step How To.

Helen clearly pays exquisite attention to her farming, conducts research and share her knowledge with others. She operated an Organic orchard in California, together with her husband Carl Rosato, who very sadly died in a farm accident in 2019. Helen and Carl together pioneered ways to raise tree fruit with no pesticides at all. Helen has expertise in ecological weed, disease and pest management, minimal soil disturbance, and managing living mulches, providing soil fertility without manure-based compost, and cultivating habitat for beneficial species. There is lots to learn from this book.

The endorsements for The Ecological Farm are staggering: fifteen well-known ecological farmers (fourteen men and one woman, what’s with that?). Clearly, this work is held in high regard by many experts in the field. The love of farming goes beyond achieving high crop yields, embracing connection with the land and all its forms of life. Helen says “The process of creating farms and gardens opens my eyes to awe, attunes my ears to listening, and offers the gifts of curiosity, discovery and deep connection.”

The ecological approach in this book goes beyond organic, which in the wrong hands simply substitutes a different set of substances for the banned ones, and doesn’t look any deeper. Helen has measured the effects that her actions have had on her land and crops, and shares her results so that we too can grow nutrient-dense foods and leave the environment in a richer, more balanced state than we found it.

The book contains dozens of Helen’s own beautiful full-color photos of plants, pests, birds, fruit trees and vegetables in various combinations. There are prepared forms for monitoring problems and planning interventions. There is a Vegetable Crop Growing and Troubleshooting Guide, a section on Vegetable Crop Insect Pests and Interventions, one on vegetable crop diseases, and similar sections for tree fruit crops.

The first half of the book sets out ten empirical and practical Principles for Managing Ecological Relationships. As the name emphasizes, it’s about managing relationships, not managing crops for highest yields, regardless of what else happens. The connections that form healthy farming ecosystems require us to pay attention, and avoid outside inputs in favor of balancing what is happening on our own farm. There are some excellent charts of applying the ecological principles.

The Principles include creating above- and below-ground diversity; minimizing soil disturbance; maintaining growing roots year-round (living plants secrete 30-60% of the carbon they capture from the air during photosynthesis down into the soil); growing your own carbon; adding organic residues all season; focusing on carbon fertilizers; recycling rather than importing nutrients; fertilizing selectively; weeding selectively; and creating beneficial habitat as close to the crops as possible.

There are many ways to build soil organic matter without removing large quantities of inputs from someone else’s land (not sustainable or fair, as Helen remarks); many ways to build habitat for beneficial organisms; many actions that can steer plants, animals and fungi towards better balance, so that the soil microbial community will thrive and cycle nutrients continuously.

Helen tells that when she started farming, she behaved like a “nitrogen hoarder”, focused on maximizing the amount of nitrogen the soil had available, and topping it up with compost and cover crops if the soil held less than the requirement for the next crop. Her soil management went through a three-stage evolution: She started to view the abundance and diversity of active microbes as the important bit, and the nitrogen level as merely a sign of that activity. Next, she moved to consider the whole soil organic matter system, rather than the parts as separate features to measure. Thirdly, she researched soil carbon and realized that microbially-active carbon was essential fuel for the soil microbes, and deserved more attention.

Actual measurements showed that, contrary to careful calculations, her soil levels of nitrogen, phosphorus and potassium were becoming too high. Helen had been generously adding sheep manure and clover compost at 7-10 tons/acre (18-25 tons/ha). She changed to using mown clover as her main fertilizer, and learned to manage the carbon:nitrogen ratio, with the goal of achieving steady decomposition of organic residues and increased microbe populations and diversity. Simply adding more high-nitrogen material will not provide good crops! We need to build carbon in our soils, and optimize organic matter decomposition and nutrient cycling.

Helen discovered that the C:N ratio of mowed clover living mulch residue varied according to the time of year, being highest (least nitrogen, nodules not yet formed) in July and lowest (most nitrogen, clover flowering) in August and September. This affects nutrient availability and decomposition rate. Vegetable crops do best in Helen’s system if she tills once a year and regularly applies both high-C and low-C residues on the surface. The continuous organic surface residue supply is much better than an annual large dose. Timing when and how we apply organic residues influences their C:N ratio, and hence how we build up carbon in the soil.

Minimizing tillage is another way to build soil organic matter. Incorporated clover releases nitrate-nitrogen into the soil much more quickly than surface-applied cut clover. If your soil has an active and diverse microbial community, incorporating legume cover crops in spring can give a quick burst of nitrogen (for a few weeks), then a sustained regular release of more as it slowly decomposes. With no tillage there is a lag time. No-till does keep the fungal food webs unbroken, which has advantages. It is important to focus on the carbon fertilizers rather than fast-release nitrogen fertilizers. Since 2016, Helen has used only mowed living mulch as fertilizer for most crops, paying close attention to the timing of mowing. The vegetable plots also benefitted from the living mulch in the row middles growing over the bed after the food crop was finished.

I had to look up “row middles” to understand the methods better. With rows of fruit trees, row middles are the aisles between rows of trees. They can be planted in cover crops, which can be mowed and the cut material blown into the tree rows to act as mulch. The photos of vegetable production (other than her home garden) seem to show aisles wider than the beds, so that less than half of the land is in vegetables and more than half is in cover crops. This fits with the method of growing lots of cover crops as the main source of soil fertility. And with Helen’s method of always leaving half of the living mulch row middles unmowed to provide good habitat for beneficial insects. Over here on the East Coast, I am more used to intensive vegetable farms with narrow aisles between beds, perhaps because land is more expensive, perhaps because Bermuda grass is so invasive as to scare off anyone who might consider permanent paths. Jennie Love, a flower farmer in Philadelphia, uses Living Walkways. Hers are 21″ wide, mostly grass and weeds, and require mowing every single week. Helen’s are more focused on legumes, especially clovers.

To focus on a soil organic matter system driven by microbial activity, attention goes to C:N ratios, optimal decomposition speed and nutrient cycling of the cover crops, mulches and composts. As Helen admits, this can be overwhelming, so don’t change everything at once! As you gain experience growing your own fertilizers, you can cut back on imported fertilizers. Do provide a diversity of organic materials throughout the growing season. Having just one kind, all at once is, for the soil, like us eating a whole giant cheese pizza! Soil “indigestion” takes the form of an over-population of just a limited specific microbial community.

Decreasing nutrient inputs and increasing application of organic residues leads to an increase of mycorrhizal fungi. Including chipped woody compost increases the soil carbon. Adding cover crops increases not just the soil nitrogen but also the carbon as more microbial bodies are born, feed and die. Raw organic matter is to be avoided as it acts like an unmanageable surge that can burn plants (by releasing high levels of salts and toxic byproducts) and leach nutrients. In hot humid climates, it is best to aim for slow decomposition to balance the climate’s effect causing fast decomposition. Aim for ten weeks’ worth of nutrients, not more, and watch for foliar signals of nitrogen or phosphorus deficiency that last for more than 3 weeks – a sign that things are out of balance.

In early spring (if early harvest is a priority) you will need to provide easily available nutrients. The first couple of years after switching your focus to carbon, you may be frustrated by the slow rate of decomposition and the lower yields. It takes weeks longer for surface-applied plant matter to release its nutrients than it does for tilled-in plant matter. This requires patience, planning and also has financial implications. Wait 2-4 weeks after incorporating organic residues, or 4-6 weeks after spreading them on the surface, before planting. Animal manure is not essential for soil fertility. After all, animal manure is simply plant matter that has been partially digested. By applying the plant materials to the soil surface, the digestion is done by small soil animals. It’s not so different!

Letting living mulch grow tall in very wet or very hot weather will help dry or cool the soil, but don’t let the cover crop out-compete the food crops for water! Adding cut covers is also a way of adding to soil moisture. Helen is a fan of minimizing tillage, not of banning it.  Tillage decreases organic matter, microbial diversity and abundance, and disrupts the fungal chains. Strip tillage tills out narrow strips to plant into, from an existing sward of cover crops. Tillage incorporates organic residues, adds air, and stirs up a burst of biological activity, helps warm up spring soils, reduces weeds and breaks up compaction. These benefits can be put to use rather than scorned. “Practice tillage with intention” as Helen advises.

Likewise, compost can be useful when starting on poor land, or needing to address some other kind of imbalance. Don’t rule it out completely! There is plenty of information about making good compost here. Did you know the critical temperature for killing most weed seeds is 145˚F (63˚C)? This book also offers a recipe for a liquid fertilizer for “emergency use” on crops showing a nutrient deficiency.

Author Helen Atthowe.
Credit Cindy Haugen

I appreciate reading work by growers such as Helen, who have done the research and experimentation and responded to the science. An average of one page of footnotes per chapter backs up her claims. I’m not a fan of myths and “woo-woo” gardening. This book includes many useful charts and graphs, so you can see the facts. A four-year experiment started with a 50-year old grass, clover, alfalfa and weed pasture, was divided into two fertility treatments. The first was strip-tilled, with the mowed living mulch blown onto the 4′ (1.2 m) wide crop plots each spring. The second was similar, with the addition of 4″ (10 cm) of clover/grass/weed hay mulch in the late summer before the spring strip-tilling. The hay was cut from another field on the farm. Crop yields were economically sustainable in both plots all four years, and there were almost no insect or disease problems. Yields improved in the second and third years. Yields of some crops were higher with the hay addition – peppers and onions significantly; dry beans and cabbage slightly.

The information on choosing cover crops advises using mixes of crops with different C:N ratios, and including legumes whenever possible. This chapter includes recommendations on inoculants, cover crops for various soil types, and “biographies” of four perennials, 15 annuals and the biennial yellow sweet clover.

The book reminds (or informs) us that being able to stop using pest control sprays starts with building the soil, making it comfortable for soil microbes and creating habitat for natural enemies of the pests. The next step is growing healthy plants, by providing optimal conditions of light, temperature and water, and managing plant competition from weeds or over-thick sowing. After that, focus on the balance of nutrients in the soil, especially carbon.

Suppress pests, rather than focusing on killing them. Spraying insecticides, even organic ones, can disrupt balance and leave you inheriting the task of the creatures you killed. Killing all the prey starves the predators who were keeping the prey in check. Learn to intervene with the least possible impact. Tolerate non-threatening amounts of pest damage. Approach in this order: prevention, pest diagnosis, research, monitoring and ecological decision-making. Minimal-impact interventions include trapping and pest-specific microbial insecticides like Bt (which could require ten sprayings to achieve 98% damage-free Brussels sprouts); moderate-impact interventions include broader-spectrum microbials and materials like soap, horticultural oils and minerals; heaviest-impact interventions (those likely to injure non-targets) include using neem oil, pyrethrin, pyrethrum powder and spinosad.

Designing and maintaining a disease-suppressive ecosystem is the title of the section that focuses on preventing diseases. Crop rotations and diversity of crops and other plants are at the top of the list.

Plant competition is the description of the effect of weeds and over-thick planting. We are encouraged to focus on the weeds most likely to cause problems leaving those that can peacefully co-exist with the crop. Knowing and understanding weed ecology is important: when and where does this weed do best? How can you make your vegetable gardens less comfortable for the weed?

Perennial weeds that spread underground need good attention. Helen deals with quack grass, which takes about four years to become a serious invasion problem, when three passes with the tiller 7-10 days apart in spring are needed. I’ve lived with quack grass (couch grass), a cool-weather invasive. It’s a challenge, but I do think the warm-weather Bermuda grass (wire grass) is worse. Tilling also deals with that.

Crop rotations, especially of crops that grow in different seasons, underground crops that need soil disturbance to harvest them, and crops that rapidly cover the soil, are a big help. Helen recommends growing a full-season perennial cover crop on 25-50% of your garden beds or farm area in production each year to break annual weed cycles.

Some cover crops, including cereal rye, hairy vetch, red clover, sunflowers and mustards all exude allellopathic compounds that inhibit germination of nearby seeds (weeds and crops). Often incorporating the cover crop in the soil works better than chop-and-drop, as buried plants decompose without much air, giving a stronger effect. Also tilling reduces the immediate competition from weeds. Tillage can increase yields even if you believe no-till is best! It’s a trade-off. Tillage reduces soil health. Perhaps the sweet spot is minimal tillage, such as strip tillage. Landscape fabric (reused for ten years) offers another method of weed management.

Part Two of the book (approximately half of the pages) covers an ecological approach to crop management and troubleshooting. I didn’t take as many notes of that. After the introduction to some techniques like interplanting, succession planting, making your own microbially-amended seed growing mix, and using season extension tools, the book focuses on thirty popular crops, with tips on crop management, pests and problems.

A tidbit I learned with spinach is that fall-sown plants that reach the two-true-leaf stage before winter will resume growth in late winter. I also learned that the western striped cucumber beetle has a reddish thorax, making it look more like our striped pigweed flea beetle without such sturdy leg muscles.

The crop management sections include soil and fertility needs and special ecological preferences. The problems sections describe symptoms first, then causes, then resistant cultivars and other strategies for avoiding that problem in future. A valuable reference, and good winter browsing when reviewing the season past and preparing for the coming year. The index covers a substantial 18 pages, in three columns, promising to be comprehensive!

Helen Atthowe still acts as advisor to her previous farm, Woodleaf Farm in eastern Oregon, and is a farm consultant in the US and internationally. I notice that Helen is a speaker at the November 2023 Carolina Farm Stewardships Sustainable Farming Conference.

Helen Atthowe, November 2017.
Photo from Veganic World

Planting winter hoophouse crops

Our first hoophouse radishes germinated three days after sowing. We sowed Cherry Belle and White Icicle. We would have sowed Easter Egg if we’d had enough seed left after the outdoor fall sowings.
Photo Pam Dawling

We’ve already prepared our first bed in the hoophouse and sowed our first few crops (spinach, radishes, scallions, tatsoi, Bulls Blood beets and cress). We spread the bed prep out over 5 days and the sowings over 2 days. I’ve written lots about our fall hoophouse planting, so I’ll give you links, mention a few updates and stick to photos otherwise.

Mid-October photo of September-sown tatsoi and August-sown Tokyo bekana. Fast-growing crops make good use of small windows of time.
Photo Pam Dawling
  • Hoophouse Winter Schedule Tweaks and Improvements (pack more crops in, get higher yields, reduce or spread the workload). One change we made was to sow some early catch crops in areas that weren’t needed for all-winter crops until later. We mostly used tatsoi and Tokyo bekana, both fast–growing leafy greens. We intended to grow some early beets too, but the seed didn’t germinate. A new crop last winter was cress, Creasy Greens Upland Cress and Belle Isle Upland Cress from Southern Exposure. They take 50 days to maturity (in spring). We had two good intentions we did not manage to follow through on. One was to let some of the cress flower, to feed beneficial insects. And I think we got too impatient. The other was to notice which one of the two kinds we prefer and just grow that one. We didn’t manage to keep good enough records on that, so this winter we are obliged to repeat the experiment, with more good intentions!
Belle Isle Upland Cress from Southern Exposure Seed Exchange
  • Using all the space in the winter hoophouse (filler crops for random spaces, fast-growing catch crops, radish sowing dates for seamless harvests.)
  • Fall hoophouse bed prep and shadecloth removal (packing away the giant piece of shadecloth until May, spreading compost, broadforking and raking the beds, direct sowing the first bed, sowing seeds in an outdoor nursery bed to transplant into the hoophouse a few weeks later). This post includes a step-by-step guide to hoophouse fall bed prep. Our soil is improving each year, becoming easier to broadfork and rake. That counters the aging process of our human bodies! One change we made last year was to measure and pin down the drip tapes 12” (30 cm) apart, and use the drip tape as a guide to making furrows (drills). This is easier than using the row marker rake, as we used to do.

    Our hoophouse with shadecloth for growing summer crops. Photo Pam Dawling. We have now sewed the two pieces together, to avoid the gaping hot spot in the middle!
  • Hoophouse fall bed prep (includes an appreciation of spiders and a video of spider “ballooning”)
  • Sowing hoophouse winter crops (more details on bed prep tools and techniques, including the row marker rake if you want to use that, and links to posts about winter lettuce varieties we used in 2017/2018.)
  • Planning and Growing Winter Hoophouse Vegetables (hoophouse crop map, many links to other posts including a video and three slideshows, crop rotations, choosing winter hoophouse crops, posts about specific crops (with all the details), back up plans in case something goes wrong, and harvesting.)

    Mid-October emergency back-up seedlings for the hoophouse.
    Photo Pam Dawling. We needed to compensate for poor germination that year.
  • Preparing your hoophouse for fall and winter (includes one of my slideshows, and a more detailed discussion of lettuce types and sowing dates, information about salt build-up and our wash-down strategy in a 3-slide mini slide show, when we close and open the doors and windows, and a Be-Prepared Winter Kit list)
  • Planning winter hoophouse crops – our step-by-step process for hoophouse crop planning.

    Spinach seedlings (from pre-sprouted seed) emerged on the third day after sowing. here they are on day 4. Photo Pam Dawling
  • Winter hoophouse growing (includes a round-up of earlier posts, and a discussion about the value of crop rotation in the hoophouse, and a list of 20 benefits of having a hoophouse.)
  • Spinach variety trial conclusions This year we are growing Acadia.  Johnny’s do not recommend this variety for late fall or winter sowing, but it did very well in our hoophouse, sown in September, October, November and January.
  • September in the hoophouse: sowing spinach 
Two jars of sprouted spinach seeds and grits to prevent the damp seeds clumping. presprouting spinach seeds for a week in a fridge gets round the impossibility of getting spinach to germinate in hoophouse soil at 80F (27C) as it is September 11.
Photo Pam Dawling
One side of our hoophouse on Sept 10. Three beds with cover crops of buckwheat and sunnhemp (which got bitten down at a young age by Something), and one bed under solarizing plastic in hopes of killing nematodes. Photo Pam Dawling
Zipper spider on the pepper plants in our hoophouse September 10.
Photo Pam Dawling

Cover Crops for September: wheat and crimson clover

Crimson clover is a beautiful and useful cover crop.
Photo Kathryn Simmons

Note: the day after I posted this I found I was mistaken in believing barley to die at a warmer temperature than oats, so I’ve edited it.

Focus Cover Crops for September: Winter Wheat and Crimson Clover

In August I wrote about cover crops such as millets, southern peas, buckwheat which are frost-killed. If it’s still too early to sow your winter cover crops, sow summer cover crops. Before I get to the wheat and crimson clover, I’ll mention some other useful seasonal cover crops.

Winter-killed, not frost-killed, cover crops

There are also cover crops that are not frost-killed, but die later in the winter, at colder temperatures, such as oats and barley. Only sow oats or barley if you are sure you can get them turned under or killed by cold winter weather before they seed. They will not mow-kill, so if the weather doesn’t kill them, you will have to turn them under. Be careful buying feed-grade seeds (rather than Organic seed-grade), as they can contain weed seeds including GMO canola.

Late corn undersown with oats, now mowed high, and the sweet potato patch now sown in winter wheat and crimson clover.
Credit Ezra Freeman

If the area is clear of vegetable crops by 40-60 days before frost, sow oats to winter-kill. If possible add a legume (soy and spring peas are easy, and will be killed by the frost, so they won’t complicate food crops next year). For us with a first frost date of October 14-20, the cut-off date for oats is September 7, or September 15 if we really push it. Sowing too late means you don’t get enough growth in the fall, and the soil is not adequately protected from erosion or from weed growth.

We sow oats after growing early sweet corn, spring broccoli, spring-planted potatoes, cabbage, kale, or early season spinach, lettuce, beets, carrots. Spring oats die after three nights at 20°F (-7°C), or a single plummet to 6°F (-17°C), leaving the plot quick to prepare for early crops next year. Winter oats are hardier, but my goal with growing oats is for them to die in winter. After oats or other winter-killed cover crop, we like to plant our early spring food crops, peas, cabbage, broccoli, carrots, March-planted potatoes, spinach and the first sweet corn.

Don’t let your cover crop barley go to seed! Photo USDA

Fall-sown barley (Hordeum vulgare), grows even faster than oats, but not as quickly as winter rye, and it won’t die as early in the winter as oats. Barley dies at 17°F (-8°C). It usually will die in Zone 7 and colder regions. The dead barley residue protects the soil through the winter, and dries into what Barbara Pleasant calls “a plant-through mulch” in spring in cold zones.

See Planning Winter Cover Crops, a post that includes my Short Simple Guide to Winter Cover Crops and my slideshow Cover Crops for Vegetable Growers. Oats, barley, wheat and rye sown too early can head up and seed before you get to winter, making them less useful, and more of a weed problem.

Winter-hardy grass cover crops to sow in September

It is too late for us to usefully sow cover crops that are not frost-hardy, as they won’t make enough growth before getting killed.

Winter rye and winter wheat are two grass cover crops that can be sown in the mid-Atlantic in September. Wheat is easier to incorporate than rye and has less of an allelopathic effect on small seeds, the inhibition of germination that lasts three weeks after rye is turned under. It’s true wheat doesn’t produce as much biomass as rye, so there’s the tradeoff. We sow wheat if the area is ready for cover crops 20-40 days before frost. This allows us to make faster use of those plots in the spring, compared to plots sown to rye.

Winter wheat
Photo USDA

For us wheat is a good, trouble-free winter cover crop. Winter wheat prevents erosion, suppresses weeds, scavenges excess nutrients, adds organic matter, encourages helpful soil microorganisms, and the fine root system improves the tilth. It is less likely than barley or rye to become a weed; easier to kill than barley or rye; cheaper than rye; easier to manage in spring than rye (less bulk, slower to go to seed); tolerates poorly drained, heavier soils better than barley or oats. If you have leftover seed, wheat can be sown in spring – it will not head up, but “wimps out” when the weather gets hot.

The challenges of wheat are that it does not have good tolerance of flooding, and is a little more susceptible than rye or oats to insects and disease.

Secondary cover crops in September:  Include legumes where possible

With careful planning, you can grow next year’s fertilizer for your later spring-planted vegetables! Legumes grow nitrogen-fixing bacteria on their roots, which can feed the next food crop. You may need to buy a suitable inoculant if you are introducing a new legume species. You may decide to inoculate anyway, for insurance, even if that type of legume is already somewhere in your garden. Before sowing the legume seed, dampen it, sprinkle the inoculant over the seed at a “pepper on your dinner” rate, and stir it in. Then sow the seed. Be sure not to make the seed wetter than slightly damp, or you’ll need to spread it out to dry a bit before you sow.

Two other key parts of being successful are to sow the legume early enough to establish before winter halts growth, and to plan not to need that plot next year until flowering time for that legume. At flowering time, legumes have the maximum amount of the nitrogen nodules they will have. Don’t let the legume flowers set seed, or they may become a weed problem. Take notes on when various legumes flower. If you have a legume that doesn’t reach flowering, it’s not the end of the world, you just get less nitrogen for your money, and won’t be able to supply all the N needs of the following food crop.

September (40-60 days before frost) is a good time to sow clovers here, provided you can supply enough overhead irrigation. They will make some growth in our climate before winter, and then a lot more once spring arrives.

Crimson clover cover crop with bumblebees.
Photo Bridget Aleshire

Crimson clover is a good September choice, if you won’t need to prepare the area before it flowers (in central Virginia 4/16-5/2, most usually around 4/20).

For a cover crop to survive the winter, sow winter wheat with Austrian winter peas, crimson clover, hairy vetch, red clover, white clover or fava beans. Hairy vetch takes a few weeks longer than crimson clover to reach flowering. Which you choose will depend what you want to grow there next spring and when you need to plant it.

Clover for green fallow in early September

See August’s post for info on planting a Green fallow plot (Full year cover crops)

Time is running out on this for us, but you may still have enough warm weather where you are. A green fallow crop (all-year cover crop) will replenish the soil and reduce annual weeds for the following year. In late August, or early September, four weeks after transplanting your fall brassicas, especially cabbage and broccoli, but also kale and collards, broadcast a mix of clovers: 1 oz (30 g) Crimson clover, 1 oz (30 g) Ladino white clover and 2 oz (60 g) Medium red clover per 100 sq ft (9 m2). Crimson clover is a winter annual and will be the biggest and the first to flower, in April. Medium red clover is a biennial and will be the next to flower. White clover is perennial and will take over the plot as the others subside. Be sure to get the medium red clover, not the Mammoth kind that dies when mowed. Likewise, for maximum benefit, get the tall Ladino white clover, not the low-growing “wild” type. In March, mow down the old brassica stumps and let the clovers flourish. You will be mowing this patch about once a month from March to October next year to prevent the crimson clover and the annual weeds from seeding.

Cover crops to sow soon after your first frost date

I’ll say more about this next month, and because I want this website to be useful to a geographically wide range of growers, I’m including a preview here. If the area is ready for cover crops up to 10 days past the frost date, sow winter wheat or winter rye with hairy vetch or Austrian winter peas. Winter rye is hardier than any other cover crop and can take later planting dates. But it is a bit harder than wheat to incorporate in the spring. Sow winter rye from 14 days before to 28 days after first fall frost. See Working with the time you have left in the Summer Cover Crops post. Austrian winter peas can be sown later than other legumes, it’s too late for clovers.

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

The book Managing Cover Crops Profitably (third edition) from the Sustainable Agriculture Research & Education Program (SARE), is the best book I know on the subject. You buy the book for $19 or download it as a free PDF from SARE.

Success with Spinach for Fall, Winter and Spring

January spinach from our second hoophouse sowing.
Photo Pam Dawling

Success with Spinach for Fall, Winter and Spring

Spinach is a much-loved crop for us. We sow outdoors and in the hoophouse in early September for harvesting from fall through to spring (April). We sow outdoors in late September for a crop to overwinter as small plants and be harvested in the spring. We also sow in our coldframes in mid-September. These are more sheltered than the beds outdoors, and the spinach makes faster growth. We sow more spinach in the hoophouse in October and November. We sow in the hoophouse in January to transplant outdoors and in the hoophouse in February for spring harvests. We are able to keep harvesting spinach (leaves, not whole plants) from October 15 to May 25, all the way through the winter. Central Virginia is too hot to have spinach during the summer (we switch to chard).

Spinach over-wintered in our cold frame
Photo wren Vile

Unsurprisingly, I have written about spinach several times.

Spinach Variety Trials Conclusion in May 2019. Our top general favorite is Acadia, although Reflect does better outdoors overwinter. This post includes links to earlier posts about spinach varieties, including Spinach Trials Update, April 2018.

What causes spinach leaves to turn yellow, in May 2019

yellowed spinach in May. We had transplanted too soon after tilling under some big weeds.
Photo Pam Dawling
A bed of healthy green Reflect spinach on May 3
Photo Pam Dawling

What makes vegetable crops bolt and how can I stop it? March 2021

Spinach Varieties

Choose varieties that do well in climates similar to yours, in the conditions you have when you plant and harvest. We used to grow Tyee for all plantings, and were very happy with it. But it has been pulled from the market because it had disease problems in the Pacific North West, where spinach seed is grown. We have tried and not continued Chevelle, Corvair, Renegade (grows fast, but has thin leaves and bolts early in spring), Avon (Downy Mildew in winter).

Also see the 2015 Greenbank Farm Spinach Variety Trial. The farm is in Washington State. They evaluated 10 varieties of savoyed and semi-­‐savoyed spinach with two side-­‐by-­‐side replication in spring. Abundant Bloomsdale, Bloomsdale Long Standing, Butterflay, Giant Winter, Dolce Vita, Longstanding Bloomsdale, Lyra, Solstizio, Tyee, Winter Bloomsdale. The overall star of their trial was Solstizio from Nash’s Organic Produce.

Spinach plants on February 5. left to right: Avon, Renegade, Escalade, Acadia.
Photo Pam Dawling

Paul and Sandy Arnold in Argyle, New York, made a great slide show reviewing Spinach Varieties in High Tunnels.  I think it’s no longer available online, but I did learn that in 2019, their top Winter Spinach Varieties were Escalade, Carmel, Whale, Space, Reflect; top Summer Spinach Varieties: Banjo, Seaside, Woodpecker.

In 2011-2012, High Mowing Seeds in northern Vermont did a spinach variety trial with 24 varieties. Three farmers in Iowa conducted a 2021 trial of spinach varieties and seedling methods. They compared yield, bolting and yellowing among three spinach seeding methods: seeder (1x rate), seeder (2x rate), hand-seed (2x rate); and between two varieties (Kolibri, Kookaburra). Two of them found no statistically significant difference of seeding method on yield; one found no difference in yields between the two varieties, but using a seeder at a double rate produced significantly higher yields than the other two methods.

When to sow fall spinach

Spinach does not germinate in hot soil! Use a soil thermometer and wait for the soil to cool to 68F (20C), or see the next section about sprouting spinach seed in a cold place. If you have no soil thermometer, see my post chickweed, hen-bit and dead-nettle, and use the info that was originally written with lettuce in mind, for spinach! There are photos there of these three plants at seedling stage. These are winter annual weeds here, that don’t grow in summer. Once we see their seedlings emerging in late August (a cool summer year like 2023) or September (most years) we know the soil has cooled enough to sow lettuce and spinach directly in the ground.

A trick for getting good timely germination of spinach seed is to put it (in sturdy resealable plastic bags or jars) in the freezer for about two weeks. Take the seeds out of the freezer the day before you want to sow (or start sprouting them), but – important – do not open the bag or jar. Leave it to warm to ambient temperature before opening. Otherwise the warm humid air will rush in and coat the cold seeds with condensation, reducing the shelf life of whatever seed you have left over for another time.

See our Spinach Variety Trials and Planting Plan, in February 2018:

  • September 6 is our first sowing (sprouted seeds) in the hoophouse for winter harvest 10/30-2/15, or later if it doesn’t bolt.
  • We sow outdoors on September 7 (sprouted seeds) for growing under rowcover and harvesting in fall and winter.
  • September 18-20 we sow in our coldframes and outdoors for harvest in early spring, until late May.
  • October 24 we make our second hoophouse sowing, to feed us November 25 to May 7.
  • On November 9,we make a third hoophouse sowing, intending to use these plants to fill gaps in our hoophouse as other winter crops come to an end.
  • January 16 we make more sowings in the hoophouse, some to continue to fill gaps there along the edges of the beds where they won’t fight with the tomatoes and so on, which we transplant starting March 15. Most of the spinach sown on this date is for transplanting outdoors on February 21.
  • January 29 we sow in flats in the greenhouse if we see we haven’t got enough bare-root transplants in the hoophouse.
  • February 10 If we don’t have enough transplants, then on this date we sow outdoors with rowcover, for spring harvests until May 25 if we’re lucky. We have backup plans on backup plans for this!
  • In the hoophouse we continue transplanting spinach to fill gaps until March 31.

 

Sprouting seeds before sowing is a way to success in hot or very cold weather.
Photo Pam Dawling

Sprouting Spinach Seed

This very easy work-around involves soaking the spinach seed in water overnight, draining it, and putting the jar on its side in the fridge for a week. If you remember, give the jar a quarter-turn each day to even out the moisture. You are not growing bean sprouts! A little neglect will not cause harm. The ideal is to have short sprouts, not long ones, as those break off more easily.  Sow the seed in the furrows gently, by hand. If the sprouts have got tangled, add some water to float them apart, drain them, spread them on a tray, or a layer of rowcover, to dry a bit, then mix with some inert dry soil-friendly material like uncooked corn grits or bran, which will help them not stick together.

Sowing Spinach in Speedling Flats and Floating them in Water

Another option is to start the spinach in flats and transplant it all. That’s a lot of work, but we found we could save on the daily attention time and the transplant time by using 120-cell Styrofoam Speedling flats. Sow one or two seeds per cell, then float the flats all day in water. Depending on your scale, this could be a baby bath or a stock tank. Remove the flats each evening and let them drain all night (while it is hopefully cooler). With just twice a day visits and no hand-watering, this is a big time saver, and we have got good germination rates.

Transplanting spinach from a Speedling flat. Butter knives are the tool of choice for easing the little wedges out of the tapered cells.
Photo Denny Ray McElya

When it comes time to transplant, the tool of choice is a butter knife. Use the knife to wiggle a wedge-shaped hole in the bed. Slide the knife down the sloping side of the cell, and, holding the base of the plant with one hand, use the knife hand to lift and flick the plug out. If all goes well, the plug will be then be resting on the now-horizontal knife, and you can slide it into the pre-made hole and firm it in.

Growing Spinach

Spinach makes growth whenever the air temperature is 40F (4.4C) or more. So any winter protection you can provide, in the way of cozy microclimates, rowcover, coldframes, or a hoophouse, will increase your yield. Spinach is more cold-hardy than many people realize. It dies at 0°F (-18°C) unprotected outdoors. Savoyed varieties tend to be a little hardier than smooth-leaved types. Large-leaved savoyed spinach outdoors with no protection can get seriously damaged at 10F (-12C). Small-leaved plants are OK down to 5F (-15C).

Weeding rowcovered spinach in winter.
Photo Wren Vile

Our outdoor spinach gets hoops and thick rowcover (Typar, 1.25 oz/sq yd spunbonded polypropylene, with 75% light transmission, and about 6 F (3.3 C) degrees of frost protection). It can last for 6 years or more. When we got 0F (-18C) the spinach leaves that touched the rowcover got big patches of beige/tan dead cells, but the plants recovered to produce more leaves.

Ben Hartman (author of The Lean Farm) wrote Testing the Limits of Cold Tolerance in Growing for Market magazine in February 2014. He reported that his young hoophouse spinach in Goshen, Indiana, with mid-weight rowcover survived -16F (XXX). Ben points out that spinach less than 1″ (2.5 cm) tall is very cold-tolerant. Bigger plants need more protection if it’s going to get that cold.

 You can read more about growing spinach in my Cooking Greens monthly series.

Growing bare root spinach transplants

Small spinach seedlings for bare root transplants. Photo Pam Dawling

We grow our spring spinach transplants (as well as kale and collards) in the soil in our hoophouse, sowing them in late January. See bare root transplants . You can find more links and info in that post. Growing bare root transplants saves a lot of work and a lot of greenhouse space.

Harvesting Spinach

Our goal is sustainable long-season harvesting. This is important for winter crops, as making a new sowing during cold dark days will not produce much food until spring comes around. It’s like the goose that lays the golden eggs – keep the leafy “golden eggs” coming

We harvest spinach by cutting individual leaves and leaving the plant to continue to produce more.

Our rule is “Leave 8 for later” – cut off large outer leaves close to the base of the plant, being sure to keep at least 8 of the inner leaves growing on each plant. Over-harvesting leads to decline.

When we finally pull up the bolting plants in spring, I’m always amazed to see how many leaf-scars there are on each plant, showing just how much we’ve harvested.

Hoophouse spinach. Far row: bolting Renegade; Near row: Escalade.
Photo Pam Dawling

For those relatively new to this blog but living in a similar climate zone, I want to point you to The Complete Twin Oaks Garden Task List Month-by-Month. It includes a link for each month’s task list. I notice from the site stats that some of you are finding your way there, but now there are so many years’ worth of posts it’s perhaps harder to find. Happy browsing!

Book Review, The Seed Detective by Adam Alexander

 

The Seed Detective: Uncovering the Secret Histories of Remarkable Vegetables, Adam Alexander, Chelsea Green Publishing, 2022. 306 pages, $22.00.

Adam Alexander is a seed collector, seed conserver, seed distributor, gardener, and a fascinating writer. He set out to find the origin of many vegetables, dividing the book into crops arriving from east of his home in Wales, and crops arriving from the west. He is a researcher and traveler, gourmet foodie, and one-time market gardener who couldn’t sell red Brussels sprouts.

He has joyfully searched out and found many rare, sometimes endangered (and in at least one case, the last known) seeds. He grows out the seeds he is given, and returns some seed to the person who lent them to him. He is very respectful of people’s cultures, and won’t grow for financial gain any crop that has been entrusted to him. He has enchanting stories of his efforts to seek out the seeds he’d heard about, in vegetable markets and dusty cupboard corners.

He has a website, podcast, videos and seed list at https://theseeddetective.co.uk/ He has 499 varieties of vegetable seeds, and grows out around 70 of them each year, in his garden, which includes a polytunnel (hoophouse). For some of the crops, he works with the Heritage Seed Library in the UK. If you live in the UK, he will send you a packet of seeds for a donation of £1 plus £1.50 for postage. As I write this, in August, many varieties are out of stock. Seeds are maturing, be patient.

Adam explains why garlic was fed every day to Egyptian pyramid builders; how chilies from 6000 BCE were found in a Mexican cave; why there is so much confusion between squash, pumpkins, zucchini/courgettes and marrows; and why giant Christmas lima beans are popular in northern Myanmar.

Christmas Lima Beans from Southern Exposure Seed Exchange

Agricultural history and archeology contain intriguing stories, and Adam tells these tales with humor, passion, insight. Maritime history is included, so we understand why and how certain beans were valued as storable foods for the crew on long journeys, incidentally spreading the leftover beans in the land of their arrival.

From the east, Britain received various peas, fava (broad) beans, carrots before they were orange, leeks (no, they really are not native to Britain!), asparagus, lettuce, garlic and many brassicas with unfamiliar names. From the west came tomatoes, green (“French”) beans and their dried offspring, maize in its many types, lima beans, runner beans, chili peppers and the whole squash-pumpkin hyphenated extended family (except Lagenaria siceraria gourds).

This book includes global histories and geography, and starts from a British perspective in the demarcation of East and West. There is a mistaken reference to Thomas Jefferson’s New York State home of Monticello. Elsewhere, the author correctly locates Monticello in Virginia. Jefferson did rent a house in New York City while Secretary of State. “The only person who never makes a mistake is the person who never does anything!” (Theodore Roosevelt)

Adam truly wants us all to enjoy healthy food – this is far from dry research. Vegetables have been industrialized to maximize profit for some at the expense of those who toil in the fields. Crops have, in some cases, been patented. Their flavors and nutrients have been ignored. We can change this. We can rebuild biodiversity, bring back flavor and the enjoyment of eating vegetables! We can put plants “at the heart of good cuisines and health” as Tim Lang says in his Foreword.

In his previous life, Adam was a film and television producer, used to traveling widely. In his introduction, Adam tells of an evening when his film crew took over the kitchen of their hotel in Donetsk, because they were hungry and the kitchen staff were on strike in protest at the foreign film crew staying there. Adam was able to shop well, with a very favorable currency exchange rate. He found some tennis-ball sized sweet red peppers with a fiery heart. They enjoyed their dinner and Adam was able to take some seeds home. This started his seed detective journey. From then on, he used every opportunity to seek out farmers’ markets and ask the stall-holders about local varieties. He started to build a seed library, because he realized some of the seeds were in danger of going extinct.

His began to wonder about how those crops had arrived in that country, and what was their place of origin. There were eight Centres of Diversity identified by Nikolai Vavilov, who created the world’s biggest seed bank, the All-Russian Research Institute. Since then, additional Centres of Diversity have been recognized, such as in Australasia and Africa. In this book, we meet plants from just three of those Centres: the Fertile Crescent in the Middle east, Mesoamerica, and the northern parts of Peru, Ecuador and Bolivia. These hilly or mountainous, tropical or sub-tropical regions are now associated with drought, but at the time of domestication 12,000 years ago, were rich in natural resources including rainfall. Our current day vegetables are the result of Neolithic farmers selecting plants to save for seed.

According to the historian Mary Beard, the Romans were the first society to export their food culture as part of their brand, Cabbages, kale, cauliflower, broccoli, asparagus, lettuce and leeks all traveled with the legions, as familiar comfort food to fuel them for the invasions. Sophisticated Arabic irrigation systems enabled Moors invading Spain in the eighth century CE, to plant saffron, apricots, artichokes, carob, eggplants, grapefruits, carrots, coriander and rice, which all became basic ingredients of Spanish cuisine. Vegetables have been traveling the globe for a long time! Here I cannot include much of the particular seed tales, so read the book!

Adam Alexander shopping for seeds. https://theseeddetective.co.uk/my-book/

Adam’s first tale is of a local pea variety in Laos. Through an interpreter, he asked a market stall-holder about some pea seeds she had for sale. To his every question, her unvarying reply was “Of course”. They were peas, they grew tall, she saved the seed herself, and had been doing so for a long time, and of course, the whole pod was edible. When he got them back to Wales and planted them in late spring, they grew, and grew, topping his extended trellis. They produced abundantly and were delicious. His short row of peas also produced over a kilo of seeds!

Peas were domesticated in the Fertile Crescent over 8,500 years ago, from a twining winter annual in Syria. Peas we eat today come from two species, the round (mostly grown for drying) and the wrinkly (most fresh-eating peas). 2,000 years ago, the Syrian pea crossed with a wild climbing pea from the eastern Mediterranean area. This “modern” pea spread across the much of Asia and Europe. A third species of pea was independently domesticated in Ethiopia. In Europe up until the seventeenth century, most peas were grown to be dried and stored for winter. Later, farmers developed peas for fresh eating. At the end of the nineteenth century, the USDA had recorded 408 varieties of peas grown commercially, but by 1983, 90% had been lost, and only 25 appear in the records. This threat to human survival is mirrored with all edible crops.

Mysteries and scandals abound. One tall pea tale involves seed reputedly grown from one live among three seeds taken from an Egyptian tomb. It was shown to be identical to a common Dwarf Branching Marrowfat pea. And yet the charlatan continued in business, selling to gullible gardeners. In 1861 the Royal Horticultural Society in London tested 235 varieties of peas, and found only 11 worthy of merit (but what were their criteria?)

One of the peas in Adam’s collection is named Avi Joan, and came from Catalonia. Over ten feet tall, covered with pods of sweet tasty peas, still good when mature. A truly local variety, with only one known grower, it could have died out, but now has many growers in the UK.

The other tales of seeds from the east cover fava beans from Syria, carrots from Afghanistan, becoming orange in Holland, leeks domesticated in Egypt and Mesopotamia at least 4,500 years ago, Greek krambé (leafy greens) 2,600 years ago, asparagus depicted in Egyptian hieroglyphs in the third millennium BCE and growing wild (feral?) in Britain 2,000 years ago, lettuce domesticated eight thousand years ago perhaps in Kurdistan and Mesopotamia, and garlic originally from Kyrgyzstan and Kazakhstan. The oldest garlic remains, dated to the fourth millennium BCE, were found in an Israeli cave near the Dead Sea.

Popping garlic for replanting at Twin Oaks.
Photo Bell Oaks

After this Adam considers arrivals from the west. Excavations in Mexico have given us a timeline of South American ancestors transitioning from being hunter-gatherers to farming 12,000- 9,000 years ago, after the supply of game decreased, and pressure on gathered crops reduced availability. Many crops were introduced from outside the immediate area, including amaranth, maize, squash and chilies. About 3,000 years ago, almost all the diet was farmed. About 500 years ago, these foods reached the Europe, the Middle East and Asia.

At this point we must acknowledge that European colonizers violently displaced and killed most of the native people in North America and the Caribbean and brought in abducted and enslaved Africans. In the history of Europe, we mentioned invaders from one country to another, in much earlier days, in some cases thousands of years earlier. The past history of the human race was not all peaceful. Current events are not all peaceful. The flow of foods from one culture to another is generally a better aspect of ourselves.

Columbus, when returning to Spain from the Bahamas in 1493, brought maize, tobacco, sweet potatoes, chilies and two species of beans. Twenty years later, Cortés brought from Mexico avocadoes, pineapples, cocoa, squash, more bean species, tomatoes, cassava and potatoes. These crops from a small corner of southern Mexico have become embedded in European food culture.

Tomatoes are all descended from the wild tomato Solanum pimpinellifolium, indigenous to coastal Peru. “Common” beans, Phaseolus vulgaris originated in an area from Northern Mexico to Argentina, and were grown in Britain by 1597.

Pinar del Rio Bean Seed Bank at Finca Hoyo Bonito, Cuba. Display of black bean seeds. Photo Pam Dawling

Identifying the wild ancestor of corn took scientists until the 1930’s, because the changes from teosinte to modern day maize are profound. Teosinte is a short weedy grass without any cob-like ears. It has a head consisting of about 12 kernels in two rows along a hard stem. It is now accepted that a single domestication event brought maize into the world. Domestication was a feat of impressive crop selection from genetically diverse teosinte enabling rapid mutations. The common idea that evolution takes centuries of gradual changes is not true. As if by magic, maize suddenly appeared at archeological sites. It didn’t take many generations of Neolithic plant breeding 10,000 or more years ago in the Balsas Valley in SW Mexico to open the way for breeding the 20,000 landraces of teosinte and maize that exist today.

The oldest evidence of lima beans is from 8,500 years ago, in Guitarrero Cave in Peru.

In northern Mexico and Puerto Rico the limas are the smaller more drought-resistant and heat-tolerant Sieva type. Ships returned to Europe and to Portuguese and Spanish colonies in Columbus’s time with lima beans to feed the crew. Portuguese ships from the fifteenth century on sailed round the Cape of Good Hope to southern India. The pallar types of Lima beans from northern Chile and Peru, probably crossed the Pacific to the colony in the Philippines, from the sixteenth century onwards. By the end of the eighteenth century, both types of lima beans were commonly found in China and India.

Lima beans do not grow outdoors in the British climate, but their close relative, runner beans, native to high elevations of Mexico and Central America, do very well. There is some evidence that they were domesticated by 4,000 BCE. They reached England around the beginning of the seventeenth century.

Chili peppers to grow from The Seed Detective collection

The next tale is of chili peppers (spelled chilli in the UK). What is the fascination with eating the hottest possible peppers? The earliest find of domesticated chilies is in a cave in the Tehuacán Valley in south-central Mexico, and dates from 5,000-6,000 BCE.  Five species have been domesticated, starting 7,000 years ago in Mesoamerica. The species with the hottest peppers, C. chinense, is native to the Caribbean, the Yucatan and Central America, and includes the habanero, (there is no tilde over the n, no ny pronunciation – that is just English speakers trying too hard to sound foreign!), the Dragon’s Breath, the Trinidad Moruga Scorpion and Scotch Bonnet, popular in Jamaica.

The Arawak people in the Bahamas were eating chilies when Columbus arrived in 1492 and they had arrived in Europe by 1542. Chilies traveled so fast that a Dutch botanist named the C. chinense species believing they came originally from China! People in India might not realize chili peppers came from Mexico! Chilies became such a big part of cuisine on the Indian subcontinent that every region now has its own special variety. Surprisingly, chilies did not reach North America until the Spanish brought them at the end of the sixteenth century.

Lastly we turn to the pumpkin and squash family (Cucurbita). Domestication of squash started 10,000 years ago in the Americas. Before Columbus brought back squashes from the Americas, white-flowered bottle gourds (Lagenaria siceraria) were widely grown in the so-called “Old World” for the edible seeds and as containers, and sometimes the flesh was eaten (some was toxic). This led to confusion in names between the two incompatible genera.

Today we divide squash into 4 species. C. pepo is native to North America, where it has been cultivated for thousands of years. Acorn squash and maxima squashes, such as those cultivated by the Algonquin, were valuable to the early colonizers who did not have ovens, but were able to bake hard-skinned squashes (emptied of seeds and refilled with milk and spices) in the fire ashes.

There are two types of C. moschata (native to Mesoamerica, probably northern Peru), the ones we know as Butternut squash, and the giant crooknecks, such as Tahitian Butternut, not to be confused with C. mixta Cushaw squashes (native to Florida). Many names were used for different subgroups of squashes, pumpkins, melons, gourds, cucumbers. Immature squash of many kinds have been consumed, and often called zucchini. Most canned pumpkin and commercial pumpkin pies are made from butternut squash.

Green Striped Cushaw Winter Squash, a Mixta variety, also known as Striped Crookneck. Photo Southern Exposure Seed Exchange

C. maxima is probably a descendent of wild C. andreana, native to parts of Argentina and Uruguay, where it became one of the key crops of the Native Guarani people. 1,500-year-old whole squashes have been found in Salta, in the mountains of northwest Argentina. The Spanish brought C.maxima north, where it became a widespread part of the cuisine of Native Americans, and by the end of the sixteenth century, it was found across the European colonies there. C. maxima squashes reached Japan in the eighteenth century, where they were bred to make distinctive varieties and types like Kabocha and Kuri.

A fascination with growing giant pumpkins (or squash) has developed in the last 500 years. This is not about the food supply any more than the quest for the hottest chili is.

Today, desires for nutritional value, flavor and quality are moving public opinion away from the drive to more, bigger, better at any cost. That path led us to poor quality food without much flavor, that relied on pesticides rather than pest resistance or tolerance, fungicides rather than disease-resistance, and heavy inputs of chemical fertilizers to achieve the touted high yields.

Research and development on how to feed the planet with the climate in chaos, population growing and available land shrinking, is turning more towards cultivating biodiversity and valuing sustainable and traditional farming methods. It is important for the well-being of us all that we do not divide the people who are scraping together to buy the cheapest, mostly ultra-processed, unhealthy food, from the people who can afford to feed themselves organic, sustainably produced food. Small-scale diverse vegetable farming is capable of generating more income per acre than large-scale monocropping. Our task is to ensure food justice.

Diverse farming will give us resilience in the face of climate change. Collaboration between farmers in distributing their produce is a success for us all. Home gardeners providing food for their households are part of the bigger picture of feeding the world. I learned from Adam’s book that there are more than a million acres of gardens in the UK, which represents more than 8% of all land growing crops. Maintaining local varieties can produce high yields, and, again, give us resilience. Restoring and maintaining seed libraries of local varieties around the world will bring us more strength than being in thrall to agrochemical mega-businesses. The website has a Save-and-Sow section with growing tips.

Author Adam Alexander

Tomato Varieties We Tried in our Hoophouse

Hoophouse squash between beds of tomatoes in July.
Photo Alexis Yamashita

Each year we grow two 96′ (29 m) beds of early tomatoes in our hoophouse. We plant them mid-March, start harvesting at the end of May, and pull them up at the end of July or beginning of August. By that point the plants have reached as high as we can go and the outdoor plants have started producing large amounts, so we don’t need to ask more of the hoophouse plants. Each year we grow varieties that we’ve had years of success with, plus a few new ones.

Cherry Bomb tomato.
Photo Johnnys Selected Seeds

Last year I wrote My favorite tomato varieties, about the four we trialed then: Pink Boar, Geronimo, Cherry Bomb and Estiva. We decided to grow Pink Boar and Cherry Bomb again, but somehow we didn’t! Pink Boar developed more splits and more disease in the last few weeks as the season reached its end. Cherry Bomb was out of stock when we placed our seed orders, so we tried another red cherry, Sakura.

Sakura red cherry tomatoes from Johnny’s

Sakura is a 55 day indeterminate red cherry. It did well, resisted disease. But when I checked why it didn’t seem very productive, I discovered that a confused planter had planted only one Sakura and an extra Black Cherry instead! Next year, maybe we’ll try Cherry Bomb again, or try really planting two Sakura!

We stopped growing Stupice, a 62 day indeterminate red, in favor of

Mountain Magic tomatoes in mid-July.
photo Pam Dawling

more Mountain Magic, 66 day indeterminate reds. A plan is just a plan. Somehow, a bunch of Black Cherry (64-75 day indeterminate purple) got substituted for some  Mountain Magic and some Garden Peach at planting time, due to more worker confusion. We love Black Cherry, but they take longer to pick than larger tomatoes. Some might argue that Mountain Magic at 2 oz (56 g) are not that much bigger then Black Cherry at ½-1 oz (14-28 g), but as you see, they are at least twice as heavy. The disease-resistance of Mountain Magic, Glacier and Garden Peach was medium this year.

None of us missed the Stupice, with their green/yellow shoulder problem. As I noted last year, the lack of red lycopene in the shoulders might be due to too much heat. We did try not pruning the Glacier (56 day determinate red) at all this year, and we got less of a green shoulder problem with those, so that’s worth remembering. We’d like to keep that one, as it is so fast at ripening. Sungold is still faster, though catalogs claim Glacier should be one day ahead.

Tropic tomato in mid-July. Photo Pam Dawling

This year, I wanted to try several large red round fast-maturing tomatoes, and a couple of different colors. To be chosen for our hoophouse crops, tomatoes have to mature in 80 days or less. Our main red is Tropic (80 day indeterminate red). It’s good at setting in heat and has a good flavor, but this year had a lot of disease. This summer has been peculiarly mild, up until mid-August, so not a good test of heat-setting tomatoes.

Skyway tomatoes from Johnny’s

We tried two plants each of Skyway (78 day 8-12 oz (112-168 g) indeterminate red) and, for the second year, Estiva (70 day indeterminate red). Both looked impressive: big shiny unblemished fruit. But no flavor worth reporting. Estiva had good disease-resistance, and split resistance, but was slower to fruit than the 70 day claim.

Estiva tomatoes from Johnny’s

We planned to try Premio (60 day 4 oz (56 g) indeterminate red), but didn’t get any seed. Maybe next year?

Mountain Fresh Plus tomatoes from Johnny’s

We did try Mountain Fresh Plus (75 day determinate large 8-10 oz (112-224 g) red, short plants) for a second time. “The most widely-grown market tomato in the East and Midwest” Johnny’s Selected Seeds. We are a fan of many of Randy Gardner’s “Mountain” series of tomatoes, but not this one. It wasn’t very productive, and the flavor wasn’t exciting.

 

Tropic remains our main red slicer.

 

Jubilee tomato in our hoophouse.
Photo Pam Dawling

Jubilee (80 day indeterminate orange) is our main orange slicer, and that did very well, with medium disease resistance this year. The fruit looked a little different this year. Possibly we were still sowing seed we bought during the pandemic, which came labelled “Probably Jubilee”. It’s also called Golden Jubilee.

Mountain Spirit tomato from Fedco

We also trialed Mountain Spirit (77 day indeterminate large yellow/red) and Purple Boy (80 day indeterminate large purple, Park Seeds). Neither of these wowed us much. Production was low and flavor was only so-so. We had hoped Purple Boy would be a good substitute for Cherokee Purple, which splits and yields poorly in our hoophouse. Mountain Spirit had a mushy texture.

I’m concluding (provisionally!) that large fruited tomatoes are not such a good idea for us. We do better with more productive, more modest sized tomatoes.

We came up with an idea to reduce the chance of misplanting in future. We didn’t want to write labels for every single potted tomato, so we have been labeling just the rows of 3 or 6 in a standard 1020 flat, which holds 18 pots. This means we often have more than one variety in a flat. We have small numbers of purple, brown and green pots, so we can use those for particular varieties. Mostly we have the standard black pots. Our new idea is colored dot stickers, which are often to be found in our office is oddly large numbers. I wonder if anyone else ever uses them?

Tomato seedlings potted up in the greenhouse.
Credit Kathryn Simmons

Cover crops for August: Oats and Barley

From the USDA Barley Plant Guide

Note: I edited this post in September when I found I was mistaken in believing barley was less cold-hardy than oats.

Focus Cover Crops for August: Oats, barley and other winter-killed cover crops

In August we are looking ahead, thinking about how our cover crops will be impacted by future cold weather. In July I wrote about hot weather grass cover crops, including Sorghum-Sudan hybrid (Sudex), and the millets, which are not frost-hardy.

German/Foxtail and Japanese millets are day-length sensitive. Growth is considerably less if they are sown after the summer solstice, so they are likely to be of limited use as cover crops once we reach August.

Browntop Millet could be useful in August in the mid-Atlantic. Proso/Broomcorn Millet I’m not so sure about. Pearl/ Cattail Millet is not day-length sensitive. To winter-kill and avoid seed formation, sow 60-85 days before your expected first frost.

See Working with the time you have left in the post Cover Crops in Summer. See No-Till summer cover crops in that same post (Soy, southern peas, foxtail millet). Also there, see Five Easy Summer Cover Crops that Die with the Frost (buckwheat, sorghum-sudan grass, soybeans, southern peas and sunn hemp.)

Buckwheat cover crop in flower.
Photo Pam Dawling

Buckwheat can be sown up to 28 days before the first frost.  See my article about buckwheat. Soybeans can be sown up to 45 days before frost. A mix of sunn hemp, soybeans or southern peas and other frost-tender cover crops can be grown during August (60-80 days before frost) before planting garlic in mid-fall. This method will work more easily if you mow the cover crop around your frost date, so that it is easier to make furrows in the soil. Forage radish, lab-lab beans or bell beans sown now will die back and leave almost bare soil. This is a boon for the very earliest spring transplants or sowings.

Or, instead of sowing a cover crop now, you could sow a fast-growing vegetable crop. Kale, spinach, Tokyo bekana, radishes, chard, lots of salad crops, senposai, mizuna, tatsoi, or land cress. Try Eat-All Greens, an idea form 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.

Twin Oaks Eat-All Greens on October 19.
Photo Bridget Aleshire

Winter-killed, not frost-killed, cover crops

In August, we can sow winter cover crops to be winter-killed for easy soil cultivation before early spring vegetables. Oats and barley are in this category. Oats will be killed by three nights of 20°F (-7°C) or a single night of  6°F (-14°C). Sow oats 5-8 weeks before your average first frost to get good size plants before they get winter-killed. We sow in late August and early September in Zone 7a. See Cover Cropping Your Garden by Chris Blanchard in 2002:

“Inexpensive and easy to grow, oats are a standard early fall cover crop in the northern and middle sections of North America.  A quick-growing, non-spreading grass, oats will reliably die in Hardiness Zone 6 and colder, and often in zone 7.”

It used to be nine years out of ten, here in Louisa County, VA, but our climate is shifting to be too warm in winter to reliably kill oats. This past winter (2022/2023) oats did not die. They were cold-damaged, and set back, but definitely not dead.

We can no longer rely on our winter cover crop oats getting winter-killed. March photo by Pam Dawling

Fall-sown Barley (Hordeum vulgare), grows even faster than oats, although not as fast as winter rye, and it won’t die as early in the winter as oats. Barley dies at 17°F (-8°C). It usually will die in Zone 7 and colder regions. The dead barley residue protects the soil through the winter, and dries into what Barbara Pleasant calls “a plant-through mulch” in spring in cold zones.

See Planning Winter Cover Crops. If the area has been fully harvested of food crops by 60-80 days before frost, sow a frost-killed cover crop or even a fast-growing food crop.  In central Virginia, it’s a mistake to sow rye as early as August, as it can set seed.

Winter-hardy cover crops to sow in August

Not all winter cover crops can be sown as early as August in the mid-Atlantic. Don’t sow winter rye, or it may head up before winter and drop seeds. Only sow oats or barley if you are sure you can get them turned under or killed by cold winter weather before they seed. They will not mow-kill. Be careful buying feed-grade seeds (rather than seed-grade), as they can contain weed seeds including GMO canola.

Clovers can be sown in August (provided you can supply enough overhead irrigation). September is a better time to sow clovers here, if you are sowing them in bare ground. They will make some growth in our climate before winter, and then a lot more once spring arrives.

Secondary Cover Crops in August: Undersowing for more cover crops

  • Choose vigorous food crops, but cover crops that are only moderately vigorous.
  • Timing is critical: Sow the cover crop late enough to minimize competition with the food crop, but early enough so it gets enough light to grow enough to endure foot traffic when the food crop is harvested. Often the best time is at the last cultivation.
  • The leaf canopy of the food crop should not yet be closed. With vining food crops, sow the cover crop before the vines run.
  • Ensure a good seedbed and a high seeding rate.
  • Irrigate sufficiently. The food crop will have good roots by then, but the cover crop seed will be just below the surface and will need some help to germinate.

 Green fallow (Full year cover crops)

Fall broccoli undersown with a mixed clover winter cover crop.
Photo Nina Gentle.
  • Our main use of clovers is to undersow fall brassicas such as broccoli and cabbage, with a mix of Crimson clover, white clover and medium red clover in August, to form a green fallow crop (all-year cover crop) for the following year, replenishing the soil and reducing annual weeds.
  • 2 weeks after transplanting the brassicas (August), we hoe and till between the rows, or wheelhoe.
  • We repeat at 4 weeks after transplanting, and broadcast a mix of clovers (late August-early September): 1 oz (30 g) Crimson clover, 1 oz (30 g) Ladino white clover and 2 oz (60 g) Medium red clover per 100 sq ft (9 m2)
  • In March, we bush hog the old brassica stumps and let the clovers flourish, mowing once a month to prevent the crimson clover and the annual weeds from seeding.

See my Mother Earth News post: Late summer and fall intercropping of cover crops in vegetable crops, aka undersowing.

If you have difficulty getting even coverage when broadcasting clovers or other cover crop seeds, try seeding half the crop walking in one direction, and then seed perpendicularly across your original path

In mid-August, we undersow our last sweet corn planting with oats and soybeans, as the winter cover crop, which winter-kills, leaving a plot that is easily worked up next spring. Our 6th sweet corn is sown 7/16. 4 weeks after seeding, we cultivate and sow oats and soy. In mid-March we follow with our spring potatoes. Both oats and soybeans have some tolerance for shade and for foot traffic (harvesting corn!).

Late season sweet corn undersown with oats and soy
Photo Kathryn Simmons

Sweet corn can be undersown with clover rather than soy or oats in some climates. We tried clover but found it harder to germinate in hot weather, and harder to keep the tiny seed damp. Buckwheat can be undersown in corn as a short term summer cover, but according to Sue Ellen Johnson, (co-editor of Crop Rotation On Organic Farms: a planning manual, it grows rather straggly in the shade of the corn. Soy has the advantages of tolerating shade as well as foot traffic.

We tried an idea from NY State, or undersowing winter squash with buckwheat and tilling it under just before the vines run (that was June), but here in the south, the vines ran too fast. We ended up having to wade in among the vines to pull up the buckwheat by hand!

You can drill cover crop seeds using a push seeder. See VABF Using Manually-Operated Seeders for Precision Cover Crop Plantings on the Small Farm. Don’t worry if the seed ends up deeper than ideal. It will still germinate. On a small scale, you can sow by hand, either broadcasting and raking in, or in close rows using a hoe, as if sowing

Cover Crop Planning

My book Sustainable Market Farming has a chapter on cover crops and 9 pages of charts about particular options.

The book Managing Cover Crops Profitably (third edition) from the Sustainable Agriculture Research & Education Program (SARE), is the best book I know on the subject. You buy the book for $19 or download it as a free PDF from SARE.

Stale seedbeds, triage farming, vertical farming

This week I have for you several sources of information related to small-scale sustainable farming.

Hoe the small weeds in this bed of young lettuce soon, and the closing canopy of the lettuce will shade out most weeds after that. Photo Bridget Aleshire

Triage Farming

Growing for Market has posted Triage Farming by Matt S. as a free article on their website

Matt tells of becoming farm manager on a new piece of land, with terrible drainage problems and lots of grass weeds.

“There are five spheres in which a farm can be challenged. Most farms deal with serious disadvantages in one or two of these. We were handicapped in four.” The five are location challenges, site challenges, infrastructure and equipment challenges, institutional challenges (dealing with the bureaucracies), human challenges. They didn’t have human challenges!

As a response to kicking around dried mud-balls full of grass bristles, Matt invented Triage Farming. Triage (from the French trier ‘separate out’) was a concept that came into wider use during WW1 as medics had to sort injured soldiers into three groups: those that would be OK without treatment really soon, those that were going to die whether they had treatment or not, and those who would get the most value from immediate treatment. In farming it means prioritizing using your limited resources to their maximum effect when it’s impossible to accomplish all you hoped to do.

This is not a sustainable way to farm (or live). It’s a way to preserve sanity and be most effective when things have got out-of-control. It doesn’t leave a feeling of satisfaction. But nor a feeling of despair. It can be ruthless, sloppy and minimalist.

Maybe you have never had such moments, but I have. If you have, then I recommend this article. Keep a copy handy, especially in the heat of the summer. You’ll likely not agree with every decision Matt made, but the article will help you raise your head and look around, rather than keep pushing on the task at the top of the schedule you made back in January.

Matt helps with deciding which crops to grow, and how much, if you know it’s likely to be a difficult year (new site, brand new crew, etc). He works through each of the five challenge spheres he identified and explains his response to that aspect: suitable crops for different location challenges, suitable equipment, approaches to weeding (timely, untimely, and “carnage weeding”), tools and equipment for different situations, dealing with various bureaucracies, and how to delegate to other workers.

Matt has an uplifting style, which also helps when the going gets tough.

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False and Stale Seedbeds

Future Farming Center Banner

I just read a very clear 25-page publication about using false seedbeds and stale seedbeds, including flaming. False and Stale Seedbeds: The most effective non-chemical weed management tools for cropping and pasture establishment. Dr Charles N Merfield, 2013. Lincoln, New Zealand: The BHU Future Farming Centre www.bhu.org.nz/future-farming-centre

Screenshot 2023-07-31 at 13-45-27 False-and-stale-seedbeds–the-most-effective-non-chemical-weed-management-tools-for-cropping-and-pasture-establishment-2015-ffc-merfield.pdf

“False and stale seedbeds are based on three rules:

  1. most weed seeds are dormant,
  2. tillage is the most effective means of germinating weed seeds, and
  3. most weeds only emerge from the top 5 cm / 2” of soil.
  • Both false and stale seedbeds work by the very simple process of germinating the weeds then killing them and then growing the crop.
  • False seedbeds use tillage/cultivation to kill the weeds.
  • Stale seedbeds use thermal weeders or herbicides to kill the weeds.”

Both false and stale seedbeds are made by preparing the bed 7-10 days before you plan to sow your crop, watering if the conditions are dry, then killing the carpet of emerged weeds, by very shallow tilling, hoeing or flaming. Getting the tillage correct is critical, including having a good weather-eye. Flaming will kill broad-leaved weeds, but only set grasses back by about a week. Alternatively, cover the prepared bed with a tarp to germinate and kill the weeds.

The 5-15% of weed seeds that are non-dormant are mostly in the top 5 cm/2” of the soil, and germinate very quickly. These can be very effective techniques, and this publication explains them well, and has good photos of crops, and machines such as the milling bedformer and the roller undercutter, and some fancy flamers and steam weeders, which might be equipment to aspire to, while working with spring tine weeders and shallow tillage. The explanations help with getting a better understanding of weeds seed germination, and so how to succeed with pre-plant tillage and post-crop-emergence cultivation. Timing is important, as is having the right tools for the job.

There’s also a good relevant article in Growing for Market:

Tools and strategies to reduce time spent weeding by Sam Hitchcock Tilton

Definitely read this if you are spending a lot of time weeding, or your crops are over-run by weeds. Work towards reducing your weed population each year, by preventing weeds from seeding. “Realize that one lamb’s-quarters or kochia or bindweed or galinsoga plant going to seed can be a much bigger problem next year than 10 or even 100 non-reproducing plants are now. So marshal your precious weeding resources smartly.”

Timely hoeing, while weeds are tiny and quick to die, can prevent the need for pulling weeds by hand, if you are working on a quite small scale. If your scale needs other tools, here you can learn about equipment to physically control weeds as part of your cropping system. If you are using a 4-wheel tractor, consider hillers, mini-ridgers, finger-weeders, Spyders, beet knives (L-blades), tine weeders, basket weeders.

A Thiessen walk-behind tractor cultivator, with Spyders up front, with the front of the Spyder angled towards the crop row (to pull soil away from the row), and torsion weeders at the back to weed in the crop row.

The article includes some equipment for 2-wheel walk-behind tractors, such as the Thiesson cultivator, Buddingh and Tilmor basket weeders, Even wheel hoes have weeding attachments.

Sam also describes stale seed-bedding, and advises rolling the prepared bed before tarping or watering, to provide the weed seeds good contact with the soil.

Sam’s article includes excellent photos, a tailored-for-beginners’ explanation of which tool does what and many links to other website and videos.

As Ben Hartman points out in The Lean Farm, hand-weeding is in a sign of failure to act sooner, that has led to a time-wasting scramble to correct the situation. read my review of The Lean Farm.

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Here’s an article from USDA on Killing the Crop Killers—Organically

As an alternative to bromide fumigation to kill pest nematodes, and other pests, try anaerobic soil disinfestation (ASD), an organic treatment that temporarily removes oxygen from the soil, is inexpensive and easy to apply. This method involves using a source of carbon, such as orchard grass, or mustard seed meal, tilled into the soil

Lean Times Hit the Vertical Farming Business.

Vertical farming is a code for a type of high tech hydroponics. See this article on the BBC website. Yes, hydroponics uses a large amount of energy to grow the plants. Yes, growing plants takes skill and attention. Yes, growing only a few crops is risky: people will only eat so much lettuce. Aerofarms has filed for bankruptcy, and several other “vertical farming operations” have hit financial troubles too.

Balance that with this post by Lee Rinehart from ATTRA:

Real Organic: Reflections on “The Deep Roots of Organic in Soil” by Paul Muller.

Soil is complex, with a universe of microorganisms, and cycles of carbon, nitrogen, hydrogen and many other elements. Farmers are part of the cycle. Organic farmers are seeking to make continuous improvement to the life in the soil, by observing patterns and lifeways, mimicking the native systems. We are not the center of the universe. Wendell Berry says “We don’t know what we are doing because we don’t know what we are undoing.”

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Plastic in the Organic Supply Chain Conference Report

From Modern Farmer

In early May, the Organic Center and the Organic Trade Association held the Organic Confluences conference about Reducing Plastic Across the Entire Organic Supply Chain. “While plastics serve many practical purposes on organic farms as well as for packaging and distribution, plastic production, use, and disposal cause massive amounts of pollution, which disproportionately affects low-income people and communities of color in the United States and around the world. At the conference, farmers, researchers, policymakers, wholesalers and retailers, nonprofit organizations, government agency staff and many others gathered to define the challenges in reducing plastic use, identify research needs, highlight success stories, and discuss what needs to be done to solve this growing problem.” Read a report about the conference on the eOrganic website here, with links to the conference program and slide presentations.

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Young spinach seedlings.
Photo Pam Dawling

Spinach Trial Underway to Inform Organic Seed Production

The Organic Seed Alliance is evaluating 272 spinach accessions from the USDA-ARS Germplasm Resources Information Network (GRIN) seed collection at their research farm in Washington State to assess timing of bolting and seed yield potential as part of a NIFA OREI funded project. This fall, they will share the trial results as well as their knowledge on spinach seed production and seed cleaning techniques through a webinar hosted on eOrganic, but meanwhile, read more about the project on their blog post here!

The seed production trial information is a part of an effort to aid in developing better varieties for organic farmers. “Research on the role of soil microbes on nutritional content, nitrogen use efficiency, and abiotic stress such as extreme temperatures is also underway by the project lead researcher Vijay Joshi at Texas A&M, and Ainong Shi and Gehendra Bhattarai at University of Arkansas. Together with the results of the seed production trials this project will help inform organic spinach breeders and farmers, and anyone working with seed from the USDA-ARS Germplasm Resources Information Network (GRIN) seed bank.” Results will be posted on the eOrganic project website.

eOrganic logo

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Tomato Breeding Project Fueled By Over 1,000 Backyard Gardeners

 

Some of the Dwarf Tomato Project’s diverse harvest. Courtesy of Craig LeHoullier

This 12-minute segment from Science Friday is an interview with Craig LeHouiller, who is a gardener/garden writer / tomato breeder in North Carolina. He is the author of Epic Tomatoes. In this segment he talks about the open source Dwarf Tomato Project. He and collaborator Patrina Nuske-Small aimed to preserve the flavor and beauty of heirloom tomatoes, without taking up too much space. They started crossbreeding heirloom tomatoes with smaller dwarf tomato plants. They signed up over 1000 volunteers across the world. They now have over 150 varieties of dwarf tomatoes, everything from cherries to beefsteaks, in every color. You can buy seeds from Victory Seeds, who have dedicated themselves to offering every dwarf variety produced.

 

Book Review The Home-Scale Forest Garden by Dani Baker

The cover of Dani Baker’s book The Home-Scale Forest Garden

The Home-Scale Forest Garden: How to Plan, Plant and Tend a Resilient Edible Landscape, Dani Baker, Chelsea Green Publishing, May 2022. 325 pages, 8″ x 10″, full color photos, $34.95.

 The Home-Scale Forest Garden provides plenty of detailed information to help others succeed in creating small-scale resilient low maintenance edible havens. Dani Baker started creating her forest gardens over ten years ago on Wellesley Island in the St Lawrence River, between New York and Canada (zone 4). She and her partner raise certified organic produce, grass-fed beef and goats. She tells of her successes and failures, and the strategies she developed to overcome the challenges of very wet soil, deer attacks, climate chaos and more.

The first third of this book covers planning and planting a small forest garden.  The main part of the book is a directory of plants, to help you choose plants for every level, (or “story” as the permaculturists call them). Everything from canopy trees to vines and fungi and the full range in between. The last part of the book helps with creating compatible plant groupings. Appendices give a table of nutrient accumulator plants and which nutrients each accumulates; a chart of blooming and harvest times, and a calendar of monthly maintenance tasks.

Forest gardens are modeled after nature, rather than farms: low maintenance, mixed plantings, permanent soil coverage, continuously increasing carbon sequestration. This kind of garden is regenerative: the ecological state improves each year as humus builds up. Yes, some of the plants take a long time to reach maturity and provide harvest. But herbs, berries and perennial vegetables can be harvested from your first year.

Dani and her partner David Belding bought 102 acres in the northern US, close to the Canadian border, when they retired from full-time careers, thinking to dabble in landscaping and keep a couple of horses, not to farm. The land was formerly a dairy farm, more recently hay ground with a small vegetable market farm. In their first spring, they planted a small vegetable garden, as Dani had done as a teenager. They sold all they grew, so the next year they doubled the size of the garden and bought two pigs. Retirement wasn’t boring! The garden increased to ¾ ac (0.3 ha) and the farm gained chickens, ducks, goats, beef cows and more pigs. Dani focused on the gardens, David on the livestock.

In their seventh year, Dani attended a permaculture workshop, inspiring her to create her own forest garden, fenced to keep the livestock and wild predators out. They did not want to reduce the pasture, so they chose a scrubby 100 x 200’ (30 x 61 m) area near the road. Your forest garden might be as small as 25 ft2 (2.3 m2).

They cleared the brush and designed a garden including an events space, a pond with a bridge, a patio and various plantings. Quite a bit of hardscaping (paths) was involved, meaning that long-term planning was important – no tilling everything up in November anymore! Three years later they doubled the size of their forest garden, and also expanded into the adjacent woodland, to plant under existing trees. This wooded area had standing water a lot of the year, so Dani created hügelkultur mounds, which are fully explained in chapter 4. Basically they are piles of wood trimmings that become raised beds.

For those already thinking they would miss tomatoes too much to do this, be reassured that both are possible for people with enough land. Dani has an area of market garden beds near the house. It’s also possible to integrate some annual crops within a forest garden in the early years when trees are small and plenty of light can reach the lower levels of plants. Ultimately the two kinds of gardens do better apart, as their needs and cultivation methods are different.

This is a book applying various methods, including some found in permaculture books, but it’s not a permaculture theory book, and Dani does not consider herself a permaculturist. There are none of those diagrams of the concepts of guilds, swales and redundancy in functions. You don’t have to be a believer to find value in these practices.

The six principles the author values and uses are:

  • “maximizing diversity,
  • maximizing solar absorption,
  • maximizing water conservation
  • designing for sustainability,
  • building-in redundancy and
  • minimizing human labor into the future.”

Her hedges and ground cover areas all have diverse species, and you can read which ones. By including wide paths and a patio area, Dani has created lots of edges allowing sunlight in.

Using all the vertical space increases the plants absorbing the sunlight. The seven plant levels include

  1. the overstory of trees to 30′ (9 m) or more
  2. the understory of fruit, nut and other short trees, 10-30′ (3-9 m) tall
  3. the shrub layer of berry bushes and other plants, 3-12′ (1-3.5 m) tall
  4. the herbaceous layer of perennials that die back and regrow annually, 2-10′ (60 cm-3 m) tall
  5. the ground cover layer close to the soil, including strawberries and leguminous cover crops
  6. the root layer of plants with edible roots, such as sunchokes
  7. the vining layer, with height depending on the available supports

A fungus layer can be added, but fungi aren’t plants, so you might consider them off-list.

Those creating very small forest gardens, even in a container, will have to select some layers and not others.

To maximize water conservation, create a lot of leaf canopy, keep the soil covered, choose appropriate plants, collect rainwater and runoff and increase water-absorbing mulches. At the beginning, you can cover the soil with wood chips, improving conditions both immediately and longer-term. Notice where water collects on your land and match water-loving plants with damp locations. Ponds can collect and store water, to be used as needed for watering plants, as well as increasing the habitat for more species of small and larger creatures.

Design so that you do not usually have to actively water plants–the goal is a self-sustaining garden. Be sure to include nitrogen-fixing plants, some deep-rooting plants that accumulate nutrients, some that attract beneficial insects and some “aromatic pest confusers” to make pests unwelcome.

The concept of redundancy is to provide multiple ways a need can be met, (and multiple needs met by any one function). This increases sustainability and reduces the chance of the garden failing. Water can be provided by rain, ponds and a hose. Ponds provide other functions too, increasing the network of support.

All of the above contribute to reducing future human labor, which is a fine goal for anyone, but especially those creating gardens during their retirement years. Setting up a forest garden and getting it firmly established can be quite a lot of work, depending on the scale. After that, it will provide for you, and the rest of the ecosystem.

Dani Baker, author of The Home-Scale Forest Garden

It is very important to plan your forest garden before planting anything, or making any changes to the space. You are creating long-term changes, not an annual garden that will be tilled up for a fresh start every year. Not all your plans will work out as expected, but not to worry: those who have a plan are best-placed to understand when and even how to make a change. Dani has examples, including how the dog changed the access through the hügelkultur area.

Part of your plan might be to try out plants that haven’t previously thrived in your climate. You can do this by finding the best microclimate in your garden for these crops, and improving those microclimates to suit the crops better. You can experiment on a small scale somewhere else on your land that has a suitable microclimate, to see if it will work. Assuming you don’t have huge financial resources, you’ll want to mostly grow plants you know will do well. Nut trees take a long time to provide a harvest, and who knows what the climate will be like by then? You might rather stick with berry bushes.

The first practical step, after dreaming, is to closely observe the land you plan to use, throughout every season and every type of weather. Pay attention to soil types, drainage, slopes, shade, microclimates, shelter or not from prevailing winds. Make a sketch of the various areas within your site and indicate the flows of water and wind, the sun and shade. Check the USDA winter-hardiness zone and soil types (ask your Extension agent). Dig holes after rain to assess how quickly the soil drains, and note where the rivulets run. Decide if you need to install culverts or drains. Decide if you want to include a pond, and if so, where would be the best spot.

Next, make a scale map, with accurate measurements of lengths in all directions. Mark existing trees, stumps, shrubs, slopes, rock outcroppings, flow of surface water and any human-built structures. The book explains how to triangulate distances from two known points. Add contour lines. Check the map against the territory, ensuring its accuracy.

With an accurate map you can start to pencil in your ideas, balancing all the factors already discussed. Site the big trees, ensuring you give them adequate space. Fill in with the next tallest plants, and work down by height. Make sure your taller plants won’t shade smaller ones that need good light, or ponds that benefit from solar warming. Site windbreaks where you need them, and plants that tolerate wet soil in the dampest spots.

Dani offers planning tips, like cutting discs of paper for the large trees, and moving them around your map to get the best configuration. She quotes from Martin Crawford, who wrote Creating a Forest Garden. He suggests:

  • Choose fast-growing species that will serve their ultimate purpose
  • Plant trees and shrubs close enough to create a continuous dense mass when mature
  • For windbreaks, plant a line of trees perpendicular to the direction of the wind, then plant smaller bushier plants downwind
  • Don’t expect other plants to thrive close to a windbreak, because roots compete
  • Reduce weed competition to speed forest development

Dani chose hügelkultur beds for the places that often had standing water. It was a good solution for making raised beds that would keep the plants’ roots out of the water. You will need to accumulate lots of resource materials, (unless you are making a tiny forest garden). Where possible, get the heavy piles of organic matter delivered to the high point of the land, so you only ever move it downhill!

If you need heavy equipment on the land to construct walkways, ponds, bridges, gathering areas, or install culverts, do all this before any planting. Next, do any slow-change techniques like sheet mulching to kill weeds, or grazing, or rooting with pigs (who love quack grass). Land prep before planting is explained: build raised beds, make hügelkultur mounds on a base of dead logs and branches, build swales and give them an initial planting of annual vegetables to provide roots to stabilize the mound until time for a permanent planting, and how to frost seed. Implement your deer and livestock exclusion plan, before planting a single perennial. Later, consider adding bird and bat boxes and insect hotels.

Planting large perennials is different from dealing with annual vegetables, so be guided by this experienced author. Make yourself a nursery in a separate, shady area, where you can heel-in trees and shrubs that arrive before you are ready to plant them, store “extras” and where you can propagate from plants you already have.

Here in the book you’ll find step-by-step instructions for planting bare-root trees and shrubs in the dormant season. For perspective, there is a photo of a large number of metal nametags from perennial plants that failed in Dani’s forest garden! Some failures stem from poor decisions by the gardener, others from mislabeling by the seller, or a poor or damaged specimen, or injury in transit, or bad luck (sometimes known as insufficient or faulty information). There are also instructions for planting containerized trees, transplanting, pruning, fruit-thinning, weeding and watering. And dealing with pests. Wire trunk guards can protect young woody plants from girdling by rodents, which can kill the plant.

Once you have a certain woody plant in your garden, you can propagate from that to provide more. For berry bushes, this might only add one or two years before the new plant fruits too, getting good value from your initial purchase. The book explains layering, hardwood cuttings, division and seed.

In Part 2 you can browse and select plants that seem a good fit for your forest garden. The section on nut and fruit trees explains grafted trees, “southwest injury” where bark splits in spring due to expansion and contraction of the trunk on sunny south-facing afternoons, only to get very cold at night. This is why tree trunks are sometimes painted white. Chilling periods are explained: a minimum period of cold temperatures required during dormancy for successful fruiting. Allow for global heating when you decide which fruit trees to buy!

In the plant directory, each of the descriptions includes a summary of the plant’s native range, mature height, width of canopy, soil conditions, sunlight needs, and hardiness range. A system of icons indicates some of the key functions or benefits that plant provides. Dani adds some notes in her personal observations. These sidebars include things that went wrong; extra benefits and how to take advantage of them (wild groundcovers); extra needs (such as cross-pollination, stratification and scarification) and how to provide for them; or when to forego them (blueberries, because they require acid soil); practices that can work even if you expect them to fail (transplanting shrubs in the fall in zone 4, planting shrubs with fine fibrous roots in dry locations); particular pests (raspberry vine borer, plum curculio);

There are 13 tall trees, 21 shorter trees, 27 shrubs, 38 herbaceous plants, 16 ground covers, each with a beautiful photo. Each section has some species you will likely be familiar with and some unusual ones, such as Korean nut pine, hazelbert, shipova, buffaloberry, New Jersey tea, Good King Henry, saffron crocus, water celery and cinnamon vine (air potato).

The chapter on successful groupings of varied plants will give you plenty of ideas, and tips for calculating how to include enough nitrogen-fixing plants to supply all the other plants in your garden. With plants for pollinators, rather than calculating, just go for diversity and spanning the growing season so you have something in flower all the time. Plant elderberries on the edge nearest your potato plants and they will attract beneficial wasps that parasitize Colorado potato beetles. Plant groupings are suggested for sites in full sun or partial shade. There are tips for planting orchard rows and hedge-lines with shrubs and smaller plants in between the biggest trees. You can even save time and plant a (carefully chosen!) group of nine plants in one hole!

If you become enchanted by the ideas and the photos in this book, you can start to make a plan, and maps, and a plant list, and turn your dream into reality. Even if you only have a large planter on a patio.