I’m prompted to write this post to alert growers to the publication of the revised USDA Plant Hardiness Zone Map (often incorrectly called the Cold-Hardiness Zone Map). Canada and Mexico are now included. Most areas are a quarter-zone warmer in winter than in 2012.
Click this link for more on the history of the USDA Plant Hardiness Map. Note that the original intention of this map, which shows the average annual minimum winter temperature, was to indicate which perennial plants (such as fruit trees or shrubs) would survive the winter in each location. It does also indicate which biennial and annual plants can successfully overwinter (on average). There are lots of things it was never designed for, such as indicating how long the winter lasts, or how many days will be below a certain temperature. It is very valuable for its purpose: showing which plants will survive in an average winter.
Zones 10 and 11 were added in 2012, and Zones 12 and 13 are added to the new 2023 map. Zones 12 and 13 are presently only found in Hawaii and Puerto Rico, where the average annual minimum temperatures are above 50°F (10°C) and 60°F (15°C) respectively. The new interactive map has closer definition between neighboring areas than previously, and can be examined at a finer scale. A city or town with heat-absorbing concrete, can be seen as warmer than surrounding countryside.
Comparison of plant hardiness zones mapped for the 11 largest Metropolitan Statistical Areas [MSAs (U.S. Census Bureau, 2003)] in the 1960, 1990, and recently revised Plant Hardiness Zone Maps.
This technical article by Widrlechner and others in HortTechnology in 2012 gives a short history of the Map, and explains how it can be used to predict winter-injury to plants, and avoid damage by changing shipment dates or adding plant protection. It explains how freeze injury can occur during three stages in the annual cycle of plants: firstly, extreme cold occurring during the fall, before plants have adapted to such temperature levels; secondly, during mid-winter when extreme cold can still overwhelm the plants’ adaptive survival mechanisms; thirdly, during late winter and early spring of plants “deharden” after satisfying their minimum physiological rest requirements, in unseasonably warm spells.
The article also discusses attempts in various regions to add in the effects of other weather features such as cloud cover, wind speed and snow cover. It also discusses the 1997 AHS heat zone map, and shows graphs correlating the Plant Hardiness Zone Map and the Heat Zone Map for three parts of the US. Note the date of publication: references to the “updated” map refer to the 2012 version, not 2023.
Pablo Batavian lettuce. The batavians are our most bolt-resistant heat-tolerant lettuces. Photo Nina Gentle
For summer weather, the American Horticultural Society in 1997 created a Heat Zone Map to show how many summer days are likely to exceed a certain temperature. It is not the mirror image of the USDA Plant Hardiness Map – it does not show the yearly average hottest temperature. I think an update of a heat zone map is due!
AHS Heat Zone Map 1997
According to the AHS map, I am in Zone 7 for summer temperatures (61-90 days a year reaching 86°F (30°C) or more) — right in the middle of the range. According to Weatherspark.com, from June 11 to August 30, our average daily high temperature is 86°F (30°C) or more. Summer nighttime temperatures are also an important feature of the weather, for us and our crops.
Twin Oaks is in USDA Plant Hardiness Zone 7a. (our zone remains unchanged after the November 2023 update, but we did move 5 Fahrenheit degrees milder from our 1990’s 6b to 7a in the 2012 revision). The average annual minimum winter temperature in zone 7a is 0°F–5°F (–18°C to –15°C). I have noticed that our local climate has changed on average, over the past ten-twenty years, to become drier, with milder winters and hotter summer nights.
Savoy cabbage with frost. Photo Lori Katz
Here are other features of our weather at Twin Oaks, Louisa, central Virginia:
Our average rainfall for a year is 37″ (100 cm), fairly evenly distributed throughout the year, at 2.2″–3.6″(5.6-9.1 cm) per month. February is the driest, May the wettest.
Our average daily maximum temperatures are 49°F (9.4°C) in December and January, 89°F (31.7°C) in July. The average night low temperatures are 29°F (–1.7°C) in January, 69°F (20.5°C) in July.
Our season from last frost to first frost is around 211 days. The average date of the last spring frost is April 24 (later than May 7 only happens one year in ten); the average date of the first fall frost is Oct 14 (earlier than Oct 1 only happens one year in ten).
Such grey weather! But will it rain? Photo Wren Vile
Our climate is controlled by three weather systems, mainly by moisture from the Gulf of Mexico, but also by the Bermuda High Pressure area in summer and the recurrent waves of cold Canadian air in winter. Due to the erratic movement of thunderstorms, some parts of our area may experience long periods of drought. September–November is the dry season but also the hurricane season.
Our latitude is 38° N, which is very relevant to onion growing and to daylight length.
Our period when daylight length is less than ten hours and little plant growth occurs, lasts from Nov 21 to Jan 21.
Climate Summary from Weatherspark.com
To learn some of your other weather details, see Weatherspark.com.
Front cover of Many Hands Make a Farm, by Julie Rawson and Jack Kittredge, Chelsea Green Publishers
Book Review
Many Hands Make a Farm: 47 Years of Questioning Authority, Feeding a Community and Building an Organic Movement, Jack Kittredge and Julie Rawson, Chelsea Green Publishers, November 2023. 208 pages, 6 x 9 inches, with an 8-page color photo insert. $24.95.
This little book is not a how-to-farm book, but a very readable memoir-plus-life-philosophy of two activists who also raised a family and farmed organically, built their local community and served in founder and leadership roles in the Northeast Organic Farming Association. They favor minimized external energy use, natural healthcare and debt-free living. If you have some of the same goals, this book could be inspiration and encouragement. As well as the Many Hands Organic Farm CSA, their paid jobs on the board of NOFA and Jack’s job as a board game designer kept them afloat financially. Somehow they also found time to engage in music and theatrical arts and social justice work. They wrote their book in their separate voices, as interwoven sections. It’s usually easy to tell who is speaking.
The foreword is by Leah Penniman (co-founder of Soul Fire Farm and author of Farming While Black), who became a farm intern at Many Hands in her late teens, and was praised as “no question the best worker on the farm”.
Julie and Jack met in Boston in 1976. They shared values of trusting in nature, surrounding themselves with life, using their talents, respecting details, and staying skeptical but open. Each of the authors had many years of organizing and political activity under their belt before they met and moved in together in Boston, where they made a small garden, complete with compost bin and rabbit hutch. They ate well, sold 10,000 copies of one of Jack’s board games, saved money, had their first child, and after five years, planned to move to the country. They bought a 55-acre parcel of a 400-acre ex-dairy farm near Barre, Massachusetts.
They camped there, read, planned, and planted fruit trees, and had their next child. They needed to build a house, which would require saving for a year. They wanted to use the sun and earth for heating and cooling, wood for cooking and hot water, greenhouses and root cellars. They designed matching their dream, foregoing a furnace in favor of woodstoves; earth-berming the basement; running all their plumbing in a central column far from the external walls to avoid freezing; and building a basement root cellar with fan-assisted air circulation.
Their house has three floors plus an attic, providing maximum living space for minimal foundation structure. Despite such careful planning, they do see some flaws. If starting over, they would include barns and sheds attached to the house, under the same roof. When the electricity is out, the well-pump doesn’t work. They had not planned a secondary water source. Condensation of warm moist air on cold pipes and walls came as an unpleasant surprise.
Learning that half the total cost of a house was for labor, they decided to provide that themselves. Also learning that half the total cost (these can’t both be true, can they?) was for interior finishing (flooring, walls, insulation, cabinets, and trim) they decided to do that too. Wisely, they brought a mobile home to the site to live in until the house had electricity, hot water and a septic system. They organized construction weekends for their friends. They wrote a weekly newsletter to boost morale and keep the workforce up-to-date. Julie and Jack worked as hard as they could (Jack leading the construction, Julie leading the cooking and childcare, not so revolutionary, but efficient for the short term).
In December, after 5 months of amateur construction work with a bit of professional help, the shell was closed in and they moved into the house (having spent one-quarter of the total cost). By then they had four young children. Moving into a shell of a house turned out to be a good decision for them, partly because they could change plans as needs became apparent. For example, adding a window in the north wall so they could see from indoors just what was happening outside. It was to take them ten years to finish the interior work, and it was better to live with daily improvements than to wait a long time for the perfect home.
Jack learned computer programming, took contract roofing work and did odd jobs locally, to repay the emergency family loans for closing in the house. Julie, meanwhile, together with neighbors, started the Barre Farmers Market, where she sold her crops.
Julie had left college early to save the world, and married young. When she met Jack she knew she had to leave that marriage in order to start a family with Jack. This was morally difficult for her, even while emotionally imperative. Children came along quickly (four in five years), born at home. They were raised to do chores, go to bed when told, do their best at school, tell the truth, treat others with respect, and suffer the consequences of inappropriate behavior.
Julie Rawson, author of Many Hands Make a Farm. Credit Clare Caldwell
All the children went to public school, as much to learn socialization as to get an education. Conversations round the dinner table expanded the scope of their education, as did talking in Spanish, encyclopedia quizzes and maps as wall décor. The NOFA community provided models of farm family life, including expectations of children doing chores. This gave them a good work ethic, leading to chances of paid jobs on other farms as they grew older.
Other children and young teens were drawn to the household as frequent visitors or as temporary residents. Julie calls them “children of the heart” and was happy to offer them a sanctuary from which to navigate their first rough transitions in life.
On the farm, Julie and Jack built up their soil at every opportunity, gathering organic matter wherever they went. Initially they fed themselves from a quarter-acre. After a few years, they expanded to sell at the farmers’ market. Later, Julie started a CSA (Community Supported Agriculture system) with 25 members, growing on an acre and a half, with hired workers, and a work-share option of four hours per week for a full share. They bought a Troybilt rototiller and wore out a complete set of tines every year in their rocky soil. This method worked for 30 years, upgrading to a wider tiller that could be pulled behind the four-wheel tractor they had bought, and a bed shaper. Julie calls herself a tillaholic, enjoying the results while becoming aware of the longer term damage happening.
In 2014 she became convinced by an impassioned talk by Graeme Sait, to focus on maximizing carbon in the soil as part of addressing climate change. Avoiding the oxidation of soil that comes with fluffing it up with a rototiller helps sequester carbon and reduce erosion. Julie became a convert to no-till, despite opposition from some of the workforce, and sold the tiller. Using mulches and more perennial crops are key parts of this strategy. They bought lots of rock dusts and added them to their fields, following the teachings of agronomist William Albrecht. By-then-grown son Dan was a big part of making this change happen.
The operating principles at MHOF are:
Cooperate with nature, focusing on building good soil, not on eliminating pests.
Healthy soil microbes are the highest goal, and the foundation of a strong farm.
A healthy plant is resistant to insects and disease. [Yes, healthy plants are those that are not diseased. That’s a tautology. It is agreed that a plant requires all three features of the disease triangle: a susceptible host, the presence of a disease-causing organism (the pathogen) and a favorable environment for the disease. But, is it your fault if your plant does not resist the disease? This statement seems to blame the victim for problems that occur.]
Exceptional health leads to exceptional results, another example of a statement proving itself.
Biodiversity is key, providing resilience and strengthening the farm as a whole.
Help the land grow nutritious food, by attending to soil fertility: test soils and amend as needed.
Mulch matters, adding organic matter, feeding the soil micro-organisms, keeping the nutrients cycling round.
Healthy natural landscapes include both plants and animals, and farm landscapes also benefit from animals.
Cover crops have many soil benefits and many uses.
Green growth is essential for feeding the soil micro-organisms year-round, as well as adding to the carbon in the soil.
Silage tarps are valuable to suppress vegetative growth. Yes, the plastic is not a sustainable material. But many growers have concluded that on balance silage tarps can do more good than harm. The time on the soil is short (March to May at MHOF) and the impact is less than tilling, or leaving the soil bare. The worm casts seen on the soil surface when the tarps are removed seem to prove no long-term harm.
About eight years after the kids had grown and left home, in 2007 MHOF started working with Almost Home, a program for former prisoners of the county jail, who had addiction problems. They raised money to pay these people. Two or three at a time stayed for some years, and became friends. Julie was happy when the physical work, fresh air and hearty healthy food brought about positive change in the lives of some of these struggling people. After eleven years of this challenging work, they decided to retire from the stressful work with the ex-prison men, some of whom relapsed into addiction, including two who died of overdoses.
MHOF also hired Clare Caldwell as Julie’s farming partner, and some more full and part-time staff. Clare brought breakfast sandwiches to the ex-con workers, and is got along with all kinds of people. She has been at MHOF since 2008, including birthing and raising three children in that time. She and Julie work together very well while competing in the nicest possible way to do the hardest work.
Jack Kittredge, author of Many Hands Make a Farm. Credit Clare Caldwell
The farm has an implicit guide for farm managers:
If you can’t say anything nice about someone present, don’t say anything at all. It’s OK to rag on those absent, with the understanding that “what’s said on the farm stays on the farm.”
Never ask someone else to do something that you wouldn’t do yourself (within your physical limitations).
Do exercises and affirmations before the crew arrives. Put a smile on your face. You’ll feel more alert, calmer and more open to what happens.
Be sure each day is well organized in advance. Have a written task list posted for those who forget.
Good morale follows from being occupied in something you enjoy or are good at. Know each person’s skills. Be ready to switch people around if your first estimate doesn’t work out.
Change things up. An hour is long enough for most people on any one task. Have contingency plans for different kinds of weather.
Give people as much authority as they want and can manage. Silently “interview’ workers for their next potential role on the farm.
Organize yourself out of a job. Hand over and move on. Line up the next task. Jack and Julie are now shedding overall responsibility for major parts of the farm management.
Hold a high standard for all your workers. Be clear about job descriptions and remuneration.
Distinguish between long-term workers, working shareholders and volunteers, making expectations clear.
Make it fun. Some like to sing, play word games or discuss thorny topics. Others do not.
Celebrate birthdays and important events. A cake, some music, a mention in the newsletter.
Eat together. Offer breakfast, have someone make lunch for the crew. Expect all to help with cleanup.
Offer incessant honest praise and appreciation.
Don’t be afraid to apologize and own your mistakes. This builds trust.
Resolve conflict by immediately addressing it in a non-judgmental way. Make agreements about future interactions.
Take all comers, at least once. Give everybody a fair chance. Half a day, or a day.
My reviewing came unraveled when I read that Julie and Jack did not support Covid distancing, masking or vaccinations. They believed their immunity levels (and existing intake of supplements) were strong enough to protect them from this newly emerged virus, as it does for flu. I’m happy for them that when they got Covid they both got mild cases. And may have avoided spreading it to people more vulnerable than them. Not everyone has been so lucky. Some of us have lost family members, or got Long Covid. My sympathies go out to the bereaved and those with chronic illness. I don’t get why anyone would choose to ignore the scientific evidence (once it started to emerge). Clearly the authors do believe much medical science and do take treatment for other conditions, and add preventative supplements to their fantastic diet. As they say, the politicization of the disease didn’t help us. Nor does demonizing people with different opinions, who may be living in a different situation.
After selling to a hotel chef, then a small health food store, then the Barre Insight Meditation Center every time they held a retreat, they finally had a lucky break as CSAs became more widespread and well-known.
In 1990, the federal government appropriated the word “Organic”, setting up a national inspection, certification and labeling organization. The individual statewide organic organizations joined in the National Organic Program. Soon Organic standards were allowing fudges to organic food production, such as outdoor “porches” for laying hens in densely packed poultry sheds.
Both Jack and Julie were working for NOFA, Jack on the financial and campaigning sides, Julie on coordinating the bulk organic supplies order and gathering volunteers. The NOFA Summer Conference included people from seven northeastern states, and had been run by the Vermont chapter. Sadly, it owed lots of money to two Vermont colleges, and some other chapters refused to share the debt. Julie and Jack saved the conference by finding a good location in Massachusetts, and persuading the MA chapter to host the event from 1987. They were able to get the conference back as a money-earning event and repay the Vermont loans.
They also revived publication of a NOFA newsletter, gearing up from one issue per year to six. Controversial issues were fearlessly aired (mosquito-eradication pesticides, sewage sludge as fertilizer, the industrialization of farming, big farm subsidies from taxes, the national expectation of cheap food, GMOs, and animal ID chips (dropped by the government after huge resistance from farmers).
The newsletter editors also ran seminars from 2008-2018, in conjunction with the Bionutrient Food Association, where Dan Kittredge worked. Interest in nutrient density of food lead into thinking about carbon sequestration, and no-till farming as a way to reduce carbon burn-up (carbon dioxide build-up).
Around 2015, Jack (in his mid-seventies) started to retire from NOFA/Mass involvement, and in 2020 Julie retired from her role as director. Their graceful exits were marred by a major disagreement with the NOFA Interstate Council at the end of 2020. Jack focused an issue of the newsletter, The Natural Farmer, on whether or not hydroponics should be allowed within Organics. Jack’s openness to airing dissent brought forth a blistering criticism from those who thought this idea unworthy of the newsletter.
For the conference, Julie proposed a debate about Covid vaccination and the New York state law closing religious exemptions. This idea was seen by many farmers as pointless and divisive. Instead, the topic went to an issue of The Natural Farmer, edited by Jack as his final issue. Some readers wanted to pull the issue, but it was too late. Is it censorship to exclude controversial topics, or is it avoidance of unhelpful conflict in order to focus on moving forward on agreed topics?
After 36 years working for NOFA, Julie (now 70) was happy to return to full-time farming, and continue educational work through a weekly farm newsletter and the Many Hands Sustainability Center, with weekly hosting of boys from a school providing for those recovering from sexual abuse; and seven workshops per year for members of the public. Jack is preparing to pass on their legacy, the farm, to a land trust. This means that their 55 acres cannot be further built on, and remains available to future buyers at a lower, non-development price.
Here are two people who were clear in their goals, applied themselves with gusto, achieved all their important aspirations, wrote it up, and roundly deserve to rest on their laurels.
This photo by Stephen Nix from 2019 shows me giving a presentation on cold-hardy winter vegetable crops.
I’ve just got back from the Carolina Farm Stewardship Association Sustainable Farming Conference in Durham, North Carolina. We were 875 people strong.
This year I gave two presentations:
SESSION B: SATURDAY, NOVEMBER 11, 10:15-11:30 AM
Crop Rotations for Vegetables and Cover Crops
This workshop offers ideas to design a planting sequence that maximizes utilizing cover crops and reduces pest and disease likelihood. Pam discusses formal rotations and ad hoc systems for shoehorning minor crops into available spaces. She also discusses cover crops suitable at various times of the year, particularly winter cover crops between vegetable crops in successive years. Pam provides examples of undersowing cover crops in vegetable plantings and no-till options.
Session Audience: Beginning farmers and growers wanting to increase soil health with limited space and established farmers looking to add cover crops to their rotations.
Hoophouses are ideal for growing hot-weather crops that struggle outdoors because of temperature, bugs, or diseases. In addition to growing food crops, spring and summer hoophouses are valuable for germinating seeds and growing plant starts, sowing cover crops to improve soil health, and producing flowers. Pam discusses how to cool hoophouses, tackle soil-borne diseases, and use the structures for other purposes, such as curing crops and drying seeds.
Session Audience: Farmers looking to add hoophouses to their operation or established growers who want to extend and improve hoophouse growing into the spring and summer seasons.
Cucumbers, summer squash and two beds of early tomatoes in our hoophouse in late May. Photo Nina Gentle
The handouts and the slideshows will shortly be available on the CFSA website. We had packed rooms and lively discussions. I learned new things too! One grower suggested I add Red Ripper southern peas as a possible smother crop (as an alternative to my ideas of sweet potatoes, watermelons or West Indian gherkins) for a hoophouse in summer when you want to keep roots in the ground to feed the soil microbes, but you just don’t need or want to be in there every day.
Another experienced grower of ginger suggested providing high nitrogen during the first half of its growing period (the vegetative half) and high potassium for the second (root growing) half. He has started planting his ginger in a row right next to his hoophouse, on the outside, to catch all the roof runoff water, rather than inside. He found he could not provide ginger inside the hoophouse with enough water without flooding everything else.
Plans are underway for the 2024 conference, at the Hotel Roanoke for January 19, 20, and 21. While each VABF conference has been special in its own right, 2024 will be one for the ages. VABF will be partnering with VSU’s Small Farm Outreach Program to combine conferences for the first time in each organization’s history to bring even more people together around the importance and practice of biological farming in the Commonwealth of Virginia.
The inaugural VABF-SFOP Summit brings together farmers, gardeners, eaters, educators, industry professionals, and advocates of sustainable, regenerative, biological, and organic agriculture. The three day summit includes: Pre-Summit intensive workshops, 40+ concurrent sessions, locally sourced farm meals and book sales with author signings and over 40 tradeshow exhibitors. Summit highlights include a youth program, farm tour, a silent auction and networking opportunities including regional meetings and fireside chats, morning yoga for farmers, the Taste of Virginia Expo & Social and SFOP annual awards.
Join us for enlightening and inspiring keynote presentations.
One delves into the incredible journey of organic grower JM Fortier and how his small-scale farming practices have “not only transformed his local community but also ignited a global movement that’s changing the face of agriculture worldwide.” Be inspired by the incredible journey and learn how you can apply his lessons to your own farming practices.
As an author, JM specializes in organic and biointensive vegetable production. His award-winning book, The Market Gardener, has inspired hundreds of thousands of readers worldwide to practice ecological human-scale food systems. His new book, The Winter Market Gardener, co-written with Catherine Sylvestre, has just come out.
With over 20 years of experience, JM Fortier has dedicated his career to developing, testing, and perfecting biointensive growing techniques on microfarms such as Les Jardins de la Grelinette, the Ferme des Quatre Temps, and the Old Mill.
His teachings have been adapted to different online organic farming courses in over 90 countries. His message is one of empowerment with the intention to educate, encourage, and inspire people to pursue a career and lifestyle focused on growing food with care, by and for people who care.
Niaz Dorry
The other keynote address is by Niaz Dorry, Executive Director of National Family Farm Coalition; Coordinating Director of North American Marine Alliance.
Many farmers and food providers don’t recognize their power. Join us for a session to get to know your power: the power in what you do, in the food you provide, in the economies you build, in the stewardship you bring to our collective environment, and in the love you bring to the land, water, and animals in your care. Once we know our power, we must work to build even more power through creative collaborations and market transformations that can lead to policy changes that reflect your collective values and vision for an equitable food system and a peaceful future.
Niaz has been a community organizer for over 30 years. The life changing moment came in 1994 when as a Greenpeace campaigner she switched from organizing in communities fighting for environmental justice to organizing fishing communities. From the start she recognized the similarities between family farmers’ fight for a more just and ecologically responsible land-based food system and that of community-based fishermen fighting to fix the broken sea-based food system.
She has been serving as the coordinating director of the North American Marine Alliance since 2008. One of the first things NAMA did after Niaz took the helm was to join the National Family Farm Coalition as its first non-farming member. The two organizations entered into an innovative shared-leadership model on May 1, 2018, putting Niaz in the new role of leading the work of both organizations and further cementing the relationship between land and sea.
Garlic scallions ready for harvest in early spring. Photo Wren Vile
I have often written about garlic, and here I am going to focus on planting garlic. But before that, I want to encourage you to make the most of the opportunity to also plant a bonus crop: garlic scallions.
Garlic scallions are very little work,
They come with no extra cost,
They provide a very tasty and visually attractive crop.
They will be ready to harvest in the Hungry Gap, the early spring period before any new crops are ready to harvest, when our palates are tiring of stored roots and hardy leafy greens.
You may have run out of garlic bulbs and be craving that strong flavor to brighten your meals.
Ours are ready to harvest from March 10 until we run out or they are visibly bulbing up (April 30?).
If you are selling crops, garlic scallions can bring a big return for a small bunch, because most people will be happy with 3-6 garlic scallions.
Both garlic scallions and Garlic Scapes can extend your garlic sales season.
Garlic scallions prepared for sale. Typepad.com
The easiest time to plant garlic scallions is right after your main planting for garlic bulbs, in the fall. In preparation for planting your garlic cloves for bulbs, break apart the bulbs and sort the cloves. You won’t grow large bulbs of garlic from tiny cloves, so you’ll want to separate out the good ones for bulbs. Put the tiny cull cloves in small buckets and save them to grow garlic scallions. Much more productive than throwing them on the compost pile!
You can also plant for garlic scallions at other times of year. I don’t know what the limits are. You can certainly plant in a hoophouse later in the fall than you could plant outdoors. You can certainly plant softneck varieties outdoors for scallions in January (weather permitting) or February.
Some growers are finding they can get a better income from garlic scallions than from bulb garlic, and so they are working to extend the garlic scallion season.
As an alternative to planting small cloves, you can plant whole cull bulbs, and turn a misfortune into a windfall. I don’t mean bulbs with fungal infections, but bulbs that ended up too small to sell, or use at home. Plant the small bulbs at a wider spacing than tiny cloves, maybe 5″-6″ (12-15 cm) apart. You’ll grow ready-made bunches of garlic scallions!
Garlic scallions in February. Photo Pam Dawling
Planting Garlic Scallions
We plant small cloves for garlic scallions in early November immediately after planting our maincrop garlic.
We choose a small space that is easily accessible in late winter and early spring, where we often walk by.
We make 3″ (7.5 cm) deep furrows with a hoe, only about 2″ (5 cm) apart. A lot fits in a small space.
We tumble the small cloves into the furrows, any way up, shoulder to shoulder.
We close the furrows, tamp down the soil, and cover with a mulch of spoiled hay. Tree leaves or straw would also work.
Some growers have experimented with replanting small whole cull bulbs. This could be a good way to salvage value from a poorly-sized garlic harvest.
Softneck garlic varieties can make worthwhile growth for scallions even if planted January-March. By planting later than this, it is possible to stretch the harvest period out later.
Some growers find they can get a better income from garlic scallions than from bulb garlic.
Garlic scallions ready to harvest outdoors in late March. Think what might work in a hoophouse! Photo Pam Dawling
Harvesting Garlic Scallions
We harvest garlic scallions from early March until May. 3/10 to 5/15 or later in central Virginia
Once the plants are 7″–8″ (18–20 cm) tall
We simply loosen the plants with a digging fork (rather than just pulling) and lift the whole plants out of the ground.
We trim the roots, rinse, bundle, and set them in a small bucket with a little water.
Scallions can be sold in bunches of three to six depending on their size.
Some people cut the greens at 10″ (25 cm) tall and bunch them, allowing cuts to be made every two or three weeks.
We tried this, but prefer to harvest whole plants.
We grow a lot of bulb garlic and have a lot of tiny cloves available, hence a lot of garlic scallion plants.
Our springs are short and don’t really provide opportunity to make multiple harvests.
The leaves keep in better condition if still attached to the clove.
If you do have more than you can use fresh, they can be chopped and dried, or frozen for making pesto later in the year.
Harvesting garlic scapes in May Photo by Wren Vile
Both hardneck and softneck garlic do best planted in the fall, though softneck garlic may also be planted in the very early spring if you have to (with reduced yields).
Plant when the soil temperature at 4″ (10 cm) deep is 50°F (10°C) at 9 am. If the fall is unusually warm, wait a week.
Cloves for planting should be from large (but not giant) bulbs and be in good condition. Bulbs should be separated into cloves 0–7 days before planting.
Planting deeper helps keep the garlic at a steadier temperature (milder during the winter, cooler once spring heats up)
When properly planted and mulched, garlic can withstand winter lows of -30°F (-35°C).
Garlic roots grow whenever the ground is not frozen, and the tops grow whenever the temperature is above 40°F (4.5°C).
If you miss the window for fall planting, ensure that your seed garlic gets 40 days at or below 40°F (4.5°C) in storage before spring planting, or the bulbs will not divide into separate cloves.
Plant garlic in cold areas with the goal of getting a good amount of root growth before winter has a firm grip, but not to make top growth until after the worst of the weather.
In warm areas, zones 7 and warmer, the goal is to get enough top growth in fall to get off to a roaring start in the spring, but not so much that the leaves cannot endure the winter.
If garlic gets frozen back to the ground in the winter, it can regrow and be fine. If it dies back twice in the winter, the yield will be lower than it might have been if you had been luckier with the weather.
Grey Duck Garlic logo
Grey Duck Garlic has a helpful chart by USDA winter-hardiness zone. I’ve combined their information with that I gathered previously.
In zones 0-3, if no permafrost, plant garlic in September.
In zones 3b-5, plant late-September to early-October. Plant 2-3 weeks after the first frost but before the ground freezes solid for the winter. Another way of counting is 6 weeks before the ground freezes.
In zones 5-7, plant in the second half of October. If your area does not normally get seasonally frozen ground, you could plant later.
In zones 7-9, plant in early-mid November; up till late November in zone 9.
In zones 9 and 10, look for soil to be less than 85°F (29°C) at 2″ (5 cm) deep – garlic can be planted in December or even as late as February if you have vernalized the planting stock. (Vernalization for hardneck garlic = 6 weeks of cold temperature below 40-45°F/4-7°C; softneck is less demanding) Without sufficient vernalization, the bulbs will not differentiate (divide into separate cloves).
In zones 11-13, I think plant in January or February after vernalization – check with local growers or your Extension Service, as there’s very little info out there. Also see the section below on growing garlic in the tropics. See Grey Duck Farm’s Southern Garlic Grower’s Guide by Susan Fluegel
If planted too early, too much tender top growth happens before winter.
If planted too late, there will be inadequate root growth before the winter, and a lower survival rate as well as smaller bulbs.
Garlic beds next to rowcovered broccoli beds, under a stormy sky. Photo Wren Vile
Garlic Growth Stages
Garlic and onions are biennial crops grown as annuals. They have 3 distinct phases of growth: vegetative, bulbing and blooming (bolting) The switch from one phase to the next is triggered by environmental factors. It is important to understand that it does not work to plant onions or garlic at a random date in the year.
Vegetative growth (roots and leaves). For large bulbs it is important to produce large healthy plants before the vegetative stage gives way to the bulbing stage. If planted in spring, garlic plants will be small when bulbing starts, and only small bulbs are possible.
Bulbing is initiated when the daylight reaches the critical number of hours. Garlic bulb initiation (and the end of leaf growth) is triggered by daylight increasing above 13 hours in length (April 10 here at 38°N). Soil temperatures over 60°F (15.5°C) and air temperatures above 68°F (20°C) are secondary triggers. The rate of bulbing is more rapid with high light intensity and increased temperature.
Flowering (Garlic scapes): Scapes are the hard central flower stems of hardneck garlic. Removing the scapes can increase the bulb size 25%, and also provides an additional food crop. In general, plant flowering is triggered by some combination of enough vernalization (chilling hours – maybe 10 weeks below 40°F/4.5°C), plant maturity, daylength and temperature. In cold weather the plants suppress the flowering signal. When the daylength and the temperature are both right, they trigger flowering.
Additional Stages:
Fattening up: Garlic can double in size in its last month of growth.
Drying down: Hot weather above 91°F (33°C) ends bulb growth and starts the drying down process.
Popping garlic for replanting at Twin Oaks. Photo Bell Oaks
Cover Crops for November: Winter Rye (with Austrian Winter Peas early in November)
Winter rye headed up. Mow or turn it under very soon! Don’t let it shed seed. Photo Pam Dawling
The first half of November is the last chance to sow winter cover crops in central Virginia
Our average first frost is October 14-20. If yours is later, see my post Cover Crops for October. It is still worthwhile to sow a few cover crops up to three weeks past your average first frost, and I’ll tell you about those, with ideas on what to do if your climate is past that point.
If the area is ready for cover crops up to 10 days past the frost date, sow winter wheat or winter rye and hairy vetch or Austrian winter peas.
See Planning Winter Cover Crops, a post that includes my Short Simple Guide to Winter Cover Crops and my slideshow Cover Crops for Vegetable Growers.
Last Chance Cover Crops in November: Rye
Rye grows impressive roots that improve the soil. Kauffman Seeds
Winter rye can still be sown in the mid-Atlantic in the first half of November. Winter rye is the cereal grain rye, not ryegrass. Ryegrass comes in annual and perennial forms, but neither is a good winter cover crop here. They don’t produce as much biomass as cereal rye, and can become weeds in our climate.
Winter rye is hardier than any other cover crop and can take later planting dates. Some people do sow winter wheat in early November rather than winter rye, so if you don’t have rye seed, use wheat. It can be tricky to have the cover crop seed you want, without risking buying more than you need. Sometimes it pays to use what you already have, as it may not give good germination if saved over to next fall.
Winter rye has an allelopathic effect (inhibition of germination) on small seeds, that lasts three weeks or more after rye is turned under. This means you will need to be fairly confident that the weather will allow you to till the rye in with three weeks to go before sowing carrots, spinach or other spring crops with small seeds. Transplants are not affected in the same way. If necessary, reconfigure your crop rotation plan over the winter. Plan for the next food crops after winter rye to be ones planted after late April, such as late corn plantings, winter squash, transplanted watermelon, sweet potatoes, tomatoes, peppers, June-planted potatoes, fall brassicas, and second plantings of summer squash, cucumbers, beans.
A field of winter rye with a strip of crimson clover in early May. Photo Bridget Aleshire
Adds lots of organic matter if grown to full size.
Improves the soil’s ability to absorb and store water.
The roots hold the soil together and greatly reduce erosion.
Can be used to scavenge nutrients left over from a previous legume crop or to hold onto nutrients applied for a crop that failed.
Sow from 14 days before to 28 days after first fall frost.
Don’t sow before September in zone 7 – it may set seed.
Rye makes little growth in mid-winter, but very good growth once spring arrives.
Rye can be sown in the spring, although when incorporated, oats break down quicker.
Can be undersown in sweet corn or in fall brassicas in early September, and left as a winter cover crop.
Cover crop of rye and winter peas with flowering crimson clover. Photo Bridget Aleshire.
Include Austrian Winter Peas if possible in the first week of November
See my September post for more about the benefits of including legumes with winter cover crops grasses. Also how to inoculate legume seeds with the nitrogen-fixing bacteria. Austrian winter peas can be sown later than other legumes. See my October post for more about those. See Working with the time you have left for options if you are in another climate zone.
A key to success with legumes is to sow early enough in fall to establish before winter halts growth, and to plan not to need that plot next year until flowering time for that legume. Austrian winter peas bloom here at the end of April (about a week later than crimson clover, and a week earlier than hairy vetch). (If you have a legume that doesn’t reach flowering, you get less nitrogen for your money, and will need to add some compost or other source for the following food crop.) Suitable crops for following Austrian winter peas are ones planted after May 1: winter squash, melons, sweet potatoes, tomatoes, peppers, middle sowings of sweet corn, June-planted potatoes. This is pretty much the same list as crops that can be planted after winter rye.
Austrian winter peas Photo https://www.uaex.edu
October 15 (our average frost date) is our clover/peas watershed (legume-shed?). Before that date we use crimson clover; after it (until 11/8, 3 weeks after our average frost date) we sow Austrian Winter Peas, along with winter rye or winter wheat.
Austrian winter peas winter-kill in zone 6, but are hardy in zone 7. Hardy to 0°F (-18°C). Sow Austrian winter peas at least 35 days before first hard freeze (25°F/-4°C) – in zone 7, that’s a 50% chance on 11/8. See Weatherspark.com for info on your location, or Dave’s Garden.
Last Chance cover crop
In the second week of November, we sow winter rye alone as our last chance cover crop. It is too late for any legumes.
Grain seed will store OK for the next year, but peas and beans really lose viability fast. If you still have Austrian winter pea seed from last year, I’d say throw it in this November rather than keep it for a third year, even if you are past the usual date. Germination rate goes down to 50% after a couple of years, and the plants won’t be sturdy.
Barbara Pleasant tells us two other ways cover crops can improve soil: Rhizodeposition and bio-drilling.
Rhizodeposition is a process whereby plants release sugars and other substances through their roots. The root tips host colonies of helpful microorganisms that go deeper as the roots grow deeper. For rye, this depth can reach 6 feet (2 m)!
Bio-drilling is what happens when cover crop roots “drill” into compacted subsoil. Oilseed and daikon radishes are cover crops famous for this action. The roots push deep into tight subsoil. Bio-drilling also happens when deeply rooted cover crops penetrate the subsoil and then die. With winter rye this can happen when the headed-up rye is mowed close to the ground in spring, or the rye is tilled into the top soil, severing the roots below till level. The next crop can follow the root channels made by the cover crop. This gives access to nutrients (including dead roots and microbes) left behind by the cover crop.
How to protect the soil over the winter if it is too late for cover crops
Carrot harvest cart. Our Danvers carrots have plenty of sturdy leaves to protect the soil over winter. Photo Mari Korsbrekke
Sowing cover crops too late means you don’t get enough growth in the fall, and the soil is not adequately protected from erosion or from weed growth over the winter. Try really hard not to leave bare soil over the winter.
If it’s too late to sow cover crops, but you do have a healthy growth of weeds, mow them at the beginning of November and then leave everything alone until early spring. The weed roots will hold the soil together and the above-ground growth will protect the soil from heavy rain. Having live plants will provide food for the microbial life in the soil.
If you don’t have weeds, but only almost bare soil, and it’s too late to sow cover crops, find some kind of organic mulch to cover the soil. When we harvest our storage carrots in November, we return the cut tops to the soil surface. Another seasonal option is tree leaves (sometimes conveniently left in bags by the curb). Best to ask the “owners” before lifting them. Other ideas include straw or hay. Woodchips or sawdust will work for winter protection, but don’t till them in when spring arrives. Rake them off and compost them nearby. If turned under, they use up a lot of nitrogen decomposing, and your crops will be starved.
More resources on cover crops
My book Sustainable Market Farming has a chapter on cover crops and many pages of charts about particular options.
Cover of Managing Cover Crops Profitably book from SARE
The book Managing Cover Crops Profitably (third edition) from the Sustainable Agriculture Research & Education Program (SARE), is the best book I know on the subject. You buy the book for $19 or download it as a free PDF from SARE.
Front cover of Microbe Science for Gardeners by Robert Pavlis. Photo, New Society publishers
Book Review: Microbe Science for Gardeners: Secrets to Better Plant Health, Robert Pavlis, New Society Publishers, September 2023. 192 pages, 6 x 9 inches, charts, diagrams and photos. $22.99.
Robert Pavlis is an engaging and reliable science writer, who owns Aspen Grove Gardens, a six-acre botanical garden with 3,000 plant varieties in southern Ontario. I have previously reviewed Soil Science for Gardeners,Plant Science for Gardeners, and Compost Science for Gardeners. Robert explains science in concise, minimally technological English, with researched and trialed information. In this, his newest book, Robert describes the all-important symbiotic relationships between plants and microorganisms below and above ground. A gram of fresh leaf may be home to a hundred million bacteria.
Aspen Grove Gardens. Photo from the Garden Myths website
In Microbe Science for Gardeners, we learn how we can encourage beneficial microbes and discourage those that damage our crops. We can increase our knowledge of strategies that prevent fungal, bacterial and viral diseases, and cure them. Robert Pavlis is well-known for myth-busting. No farmer likes to find their time or money has been wasted on wishful thinking with a slim hope of good results. With information from this book, we can better understand how various gardening and farming practices affect the microbes living with our plants. Is it good, bad or interesting, to till, use mulches, rotate crops or grow perennials?
This is a good point at which to say Pavlis is not a committed organic gardener. He sees compounds and ions from the plant and microbe point of view, as independent from their source. Pros and cons relate to the ingredients, not their manufacturer. There is plenty of good info and advice for organic growers. The book is studded with sidebars of Microbe Myths. Many of us will find one of our microbe beliefs shattered!
Microbes under consideration include bacteria, fungi, yeasts, nematodes, protozoa, viruses and more, such as archaea, actinomycetes, cyanobacteria and algae. And the microbe communities and microbiomes where different species support each other, such as lichens. Readers are almost certain to find some lesser-known and newly investigated gems of soil biology here, as well as be enthralled by the microscopy photos of tiny creatures we don’t see while thinning carrots.
Plants actively farm the microbes nearby, modifying the space to become more habitable. The microbes make nutrients available for the plants. The role of certain fungi covering roots and effectively increasing the surface area of those roots, increasing the nutrient-seeking range, is fairly well-known. Gardeners adding too much nitrogen fertilizer will cause the microbe system to slow down, creating a dependency on added fertilizer.
Most soils contain adequate phosphorus, although it may be in a form that requires certain microbes to make it available. Beware of adding phosphorus – do a soil test first. Fungi gather and distribute phosphorus to plants, but as with other nutrients, if too much is applied by the gardener, this inhibits growth. Remember, brassicas do not colonize fungi.
Good finished compost can still provide nitrogen 5 years later, as it finishes breaking down. Part of its contribution is via the microbes that feed on the compost, die and break down. There is much we don’t yet know about microbes, and many kinds we have not even identified yet. Recent estimates are that microbes compose 70%-90% of life on our planet.
Microbes are essential to plant growth. Some promote plant growth in ways such as bringing in nutrients and organic matter, fixing nitrogen, producing plant hormones, vitamins and antibiotics, furnishing dissolved minerals and breaking down toxins. There are 558 yeast strains found under chestnut trees. Seventy-seven of them produce a growth-regulating hormone important to roots (15 at a high level).
All carbon energy originates with plants and algae that make food using the energy of the sun. The rest of us get energy by eating those foods. Respiration releases some carbon (as CO2) back into the atmosphere, to be recaptured and used by plants. As microbes digest dead organic matter in compost piles, the process releases CO2. Nutrients are cycled around the life forms that can use them. Nitrogen is another very important nutrient, with its own energy food web.
Those who make compost are familiar with working with the carbon to nitrogen ratio. The bacteria and fungi doing the actual composting need a particular C:N ratio to live. By starting a compost pile at a 30:1 ratio, we allow for the initial release of CO2. Bacteria have a low C:N ratio (5:1 on average). When protozoa and nematodes eat bacteria, the excess nitrogen is released in forms that can be used by plants.
We gardeners also influence microbes. Soil compaction reduces oxygen levels and increases CO2. Aerobic microbes cannot thrive. Tilling does not much affect bacteria, but does rip up fungal hyphae. Tilling introduces more oxygen into the soil. Microbes in the topsoil decrease. Some pesticides harm microbes, others do not. Some microbes use glyphosate (Roundup) as food, leaving benign compounds. This is why glyphosate has a short half-life in the soil. Maintaining a steady moisture level in the soil is important for microbes.
The presence of bacteria on and inside plants is likely essential to the life of the plants. All bacteria are single-celled organisms, most are aerobic and get their energy directly from carbon sources. Most can only move themselves a distance of 5 micrometers in their whole lifetime. Only a few cause diseases.
Bacteria can only ingest small molecules, so to obtain food from plant material consisting of large molecules, they excrete enzymes that can break large molecules down to small molecules such as sugars, and then into ions. If any of the ions hit the cell wall of the bacterium, it can ingest them. Despite this inefficient-sounding mechanism, bacteria thrive everywhere! Bacteria cannot digest lignin, found in wood, but fungi can.
There are fascinating details of bacterial lifecycles, types of bacteria and fungi. Fungi cannot make their own food from carbon as plants do. They rely on other organisms in the soil or on the surface as their food. Soil is home for about 70,000 species of fungi. As bacteria do, fungi excrete enzymes that break down large organic molecules. The smaller molecules can then be absorbed and transferred several feet along the hyphae.
Oyster mushrooms Photo Ezra Freeman
Fungi can reproduce asexually (by fragmenting) and sexually (via spores, when conditions are not right for fragmentation). Mycorrhizal fungi are symbiotic with their host plants. They can increase tolerance for diseases, drought and chilling in their associated plants, as well as increase yields. The plant supplies the fungi with sugars from photosynthesis and the fungi supply other nutrients to the plant. If the soils are nutrient-rich, the plant needs less from the fungi, and transfers less sugars to them.
Yeasts also play an important role in the biosphere, including decomposition of organic matter, cycling of nutrients, and supplying plants with growth-stimulating compounds. Yeasts are a type of fungus, with complex single cells. Most convert carbohydrates into alcohol and CO2. This is the process of fermentation. Yeast lifecycle includes asexual reproduction (budding) as well as sporulation, a form of sexual reproduction, which happens when the environment becomes inhospitable. Spores can become dormant and survive until conditions improve.
Powdery mildew is a yeast fungus that grows on leaves. Research is being done into antagonistic yeast species to combat powdery mildew, which requires particular yeast for particular plants. Simply using bakers’ yeast does not work. Adding compost can sometimes help plants outgrow infections.
South Anna Butternut winter squash, a Moschata bred by Edmund Frost to resist Downy mildew Photo Southern Exposure Seed Exchange
Some fungi can attack living prey using sticky goo, poison filaments or entangling snare strands. Some yeasts contain pieces of viral RNA that produce toxins and bad beer. The interactions between bacteria, nematodes and protozoa in the soil are responsible for making many plant nutrients available. The soil environments, including the soil type and pore size, influence the amount and type of protozoa and nematodes found there, which in turn affects the number and type of bacteria. The result affects the type of plants that thrive.
Nematodes are tiny worms, up to 2 mm long, living in the top 6″ (15 cm) of the soil and moving in films of water, eating bacteria, fungi, protozoa and smaller nematodes. They are multicellular, but have only simple bodies without circulatory or respiratory systems. Some species are beneficial to plants, some parasitic, some carry viruses.
Protozoa are single-celled organisms (remember the amoeba from biology classes?), that eat mostly bacteria, and also algae, fungi, some pathogenic nematodes, and smaller protozoa. Grazing of root growth by some protozoa, and production of plant hormones by amoebae lead to an increase of root exudates, and then to an increase of bacterial populations, to the benefit of the protozoa who eat them.
Some protozoa can photosynthesize. Some live inside other organisms, large and small. Some cause human diseases, such as malaria and giardia. Nematodes, arthropods and larger protozoa eat protozoa and keep their numbers in balance. In inhospitable conditions they enter a durable cyst stage. The weight of protozoa produced each year in healthy soil is about the same as that produced by earthworms. Let’s value their contribution to nutrient cycling as much as we value that of earthworms!
Viruses are extremely small and are not composed of cells, but usually small pieces of DNA wrapped in a layer of protein. Most scientists do not consider them living or dead. They don’t grow or reproduce or move on their own, and they cannot make proteins or produce energy. They use their hosts to provide these functions. Some are beneficial, many cause diseases, some have not been studied enough for us to know. Most are short-lived, although tobacco mosaic virus can survive for decades. There are no cures for viral diseases. Prevention and limitation of spread by control of the vector is required. Bleach does not kill viruses. Vinegar is of limited effectiveness. Rubbing alcohol is the best choice for disinfecting pruners.
Most viruses infect bacteria, not plants or people. These viruses are called microphages, or just phages. Bacteria defend themselves against viruses by chopping up their genetic material. This is the process humans learned from when developing CRISPR technology. There are also bacteriophages that control plant-pathogenic bacteria. Their action is specific to particular bacteria. This is an area of active research.
Robert Pavlis, author of the “Science for Gardeners” series. Photo from his website
After covering these major types of microbe, the author takes us on an exploration of other types, including archaea, actinomycetes, cyanobacteria, and algae.
It is a mistake to think of various types of microbes living in isolation. Most live in diverse microbial communities, and also in combination with plants. “Microbiome” is the word used to describe a microbe community in a specific location, such as on a leaf, or among a tree’s roots. Microbes from neighboring communities may be in competition, or may be complementary. Microbes hoard carbon and nitrogen by deterring others with toxins and repellents.
Microbes signal to each other not as communication, but in the sense of exuding compounds that cause particular actions by other microbes, such as moving closer or further away. Potential foods exude compounds that cause microbes to produce digestive enzymes. When the sign (scent, flavor) of a predator is received by a microbe, it produces an enzyme that makes a toxic substance and secretes it into the adjacent water. The toxin makes the microbe dangerous to its predators, repelling them. The author is attentive to avoiding giving the impression that microbes are conscious and “choosing” to send “messages”, when in fact the situation is one of chance and chemical reactions.
Lichens are symbiotic relationships between three microorganisms: a fungus, a green alga or a cyanobacterium, and a yeast. The participation of the yeast is a relatively new discovery. The fungus can survive without its lichen partners, but benefits from the community. It absorbs water from the air and provides shade, benefiting the light-sensitive alga. The alga or cyanobacterium photosynthesizes, supplying sugars. The yeast helps deter predator microbes. Lichens do not harm the plants they grow on. Their presence indicates clean air.
The above-ground parts of plants are also home to a multitude of microbes, but so far they have been less studied than those in the soil. Microbes grow and reproduce on and in the plant, are washed and blown from one plant to another. Microbes can exit and enter leaves via the stomata. Immunity receptors on the leaves can detect arrival of pathogens and trigger the closure of individual stomata.
Hydroponic plants carry very few microbes, perhaps to the detriment of the health of diners. We are mistaken if we think pesticides (natural or synthetic) can kill only “bad bugs”. All bugs are interconnected and usually interdependent. Avoid sprays, as everything that kills something visible is also killing microbes we can’t see.
The rhizosphere, a thin layer of water, soil and air coating the roots, is crucial to plant health. There is a great photo showing the roots of a plant removed from the ground, coated with a layer of soil and microbes, called a rhizosheath. Look for this sign of a healthy soil as you work with your plants. There is good information about roots, root tips, the rhizosphere, the mycorhizosphere, rhiozophagy and more rhizowords.
We know that tillage reduces soil aggregation and water-holding capacity, cuts roots and fungal hyphae, and causes some microbe populations to die back, making it easier for pathogens to take hold. Crop rotation and inclusion of cover crops usually increase microbial diversity, benefiting the next crop, sometimes a little, sometimes a lot. Long cycles allow pathogens to decrease, although some soil-borne pathogens can persist for a long time. If you only have a small backyard garden, the distance you can move your crops is small, as are the benefits.
Most plant diseases are preventable with the right microbes present and active. Early-stage diseases are dealt with by the plant and its support team of beneficial and neutral microbes. Most plants fight off bacterial pathogens thanks to microbial competition, although some plants have some immunity. Often we don’t see the disease a plant has, unless it takes over. Disease spores are all around us. It’s fine to compost most diseased plants! Not those with virus diseases, or very contagious diseases like verticillium wilt.
Diseased squash, mid-June. Photo Pam Dawling
Pavlis includes information on what to do when you suspect a plant disease: Identify the problem, research reliable sources, decide if action is required, and find a solution that really works. Most often that won’t be one recommended on social media by people using kitchen products. There is a four-page descriptive list of 20 plant diseases and possible controls and management strategies, followed by discussion of household remedies such as milk or baking soda for powdery mildew (yes, if . . .), chamomile tea or cinnamon against damping off disease (yes, not sure why), neem oil against some fungal diseases but not others, and insect vectors of viral diseases (yes, if you get the agricultural kind with active azadirachtin).
The next chapter is about using microbes to grow better plants. Soils from different plant communities have different Fungal:Bacterial ratios. This ratio can be modified by adding organic matter with a high C:N ratio to improve conditions for fungi. It is hard to accurately measure F:B ratios and different methods give different answers. It is a mistake to think higher F:B ratios are always better, or that certain plants require a fixed ratio throughout their growth. There is little if any scientific research. We don’t know if trees need to grow in a high F:B ratio soil, only that forest soils do have a high F:B ratio. Possibly plants modify their own soil environment and don’t usually benefit from us making changes.
Adding the appropriate rhizobium bacterial inoculants to legumes has long been proven to work, increasing nitrogen-fixation 30%-70%. The bacteria remain in the soil for 4-40 years, and the inoculant does not need to be replied annually. Avoid adding too much nitrogen fertilizer, or the inoculated bacteria will give up. Before flowering, 60% of a legume’s fixed nitrogen is in the leaves and stems, with 40% in the roots. After mature seed forms, 80% is in the seed, 11% in the roots, and 9% in the leaves and stems.
The author cautions us to beware terms like “beneficial microbes”, which is just a marketing ploy selling non-pathogenic microbes said to increase the population in the soil. These usually include molasses or another form of sugar, which causes an initial microbe population explosion. When the nutrient is all gone, microbes die and feed each other, and population returns to its previous level.
“Effective microorganisms” is a label for a combination of up to 80 different microbes the seller thinks will improve the decomposition of organic matter. Microbes populate soils quickly by themselves, until the many species are in balance and the soil is carrying its maximum capacity. Adding more is just a waste of money and time. Slower-decomposing organic matter provides a better, longer-term benefit, increasing your soil’s capacity to host more microbes.
Bottled bioinoculants, biostimulants, biofertilizers and probiotics are usually selected microbes, mostly fungi and bacteria. Many do not contain live microbes. The Oregon Dept of Agriculture tested 51 products for bacteria and found only 9 functional. Of 14 products tested for Trichoderma fungus, none were worthwhile. Of 17 containing mycorrhizal fungi, only 3 met the label description. DNA testing showed that some products had never contained the beneficial organism. There’s lots of snake oil out there!
Compost teas are DIY inoculants, popular either as a hopefully concentrated form of nutrients or a more populous source of (hopefully good, not pathogenic) microbes. Making tea cannot increase the amount of nutrients beyond that available in the original compost. It can reduce some soil-borne diseases, if the soil, climate and microbes are exactly what is needed. Rather hit-and-miss, for gardeners and farmers. Compost tea can contain more microbes than the original compost, but they can be good, bad or even deadly, including E.coli and Salmonella. Incidentally, the deadly ones are more likely if you add molasses to your brew, Pavlis claims.
Pickled garlic scapes, okra and beets. Photo Bridget Aleshire
If all this talk of microbes on and in your food is creeping you out, relax! Wash your hands, wash your vegetables, enjoy your food. Forget soap, bleach and baking soda. A 1:1 mix of household vinegar and water can be used for a 10-minute vegetable soak, if you get sick easily. Otherwise, plain water is adequate. Remember you too are full of microbes, and your well-being depends on some of them.
You can read more of Robert Pavlis’s work on his Facebook page, website and YouTube channel:
Our hoophouse with its new inner plastic. Gabby Schulz
Putting new plastic on the hoophouse (again)
Our hoophouse has been up since 2003, and in these 20 years has had several replacements of the big roof plastic. We’ve replaced the end wall plastic less often, as it isn’t inflated and a few holes don’t matter. It’s true that old dirty plastic doesn’t let as much light in, but we are firmly on the side of not replacing end wall plastic and roof plastic in the same year.
I wrote Replacing Hoophouse Plastic in September 2017. Six years later, here we are again. This year we needed to replace all the baseboards, too, as the 2″ thick cedar had rotted, and for a few months a section of wigglewire channel holding the plastic had completely detached from the baseboard. We considered whether to buy cedar, metal baseboards or plastic lumber baseboards. I wrote about the pros and cons of each in May (2023). We ultimately decided to go with the “Hat Channel” metal baseboards from Tunnel Vision Hoops. We wanted something long-lasting at a fair price. We have a small concern about the metal baseboards lacking thermal insulation, compared to lumber, or even plastic lumber, but on balance it seemed like our best bet. No regrets, and Tunnel Vision Hoops were really helpful.
Our new hoophouse metal baseboards with wigglewire channel attached. Gabby Schulz
We removed the old plastic in the middle of September, after we had planted one bed with early crops. We continued bed prep and planting in the fresh air until October 11, when we got the new plastic on.
It took us a long time to remove all the rotted baseboards. We started out undoing as many bolts as possible, but then a helpful colleague showed up with a power reciprocal saw and cut through all the remaining ones. We also had to remove all the crumbling old duct tape we had bandaged the metal connectors and bolt heads with. Just in time, one of the crew suggested we buy Gorilla tape instead. We were pretty unhappy about all the silver dandruff of micro-plastics from the duct tape landing on our soil. Gorilla tape is thicker, stickier, less flexible, and most importantly lasts a lot longer. We saw we had used a little of it last time, in 2017, and it was still good. We had also used some pewter-grey exterior duct tape in 2017, and it was still good too. No idea where we bought that.
Close up of new shadecloth hook in place in baseboard. Gabby Schulz
We had a hope to be ready for the new plastic on October 6, but we had to deal with our slightly nervous inexperience installing metal baseboards. By this point in the year, we had to watch the forecast not only for days without rain, but also one with calm winds (below 5 mph) and we had hit a breezy spell. Our average first frost is October 15 or so, and the nights started to get chilly. Juggling all these factors, we did really well and got the plastic on during the one day that week without winds above 5 mph. We also kept up with all the October bed prep and planting, which is intense. Yay, team!
I won’t repeat what I’ve said before (click the links). If you are launching on a similar recovering, study our step-by-step instructions. If not, simply enjoy the photos.
Hoophouse frame with silage tarp spread to unroll new plastic on. Gabby Schulz
Another new idea this year was to take a 25 x 100′ silage tarp that was handy, and spread it out along the south side of the hoophouse to unroll the new plastic on. Another is to lift the roll of new plastic by inserting hoe handles in the cardboard tube, lift, and have someone walk out the free end. Much easier than pushing the roll along the ground!
2017 photo throwing a water bottle over the hoophouse to help pull the plastic. Wren Vile
We really like to have 6-8 people, who we hand pick and invite. I have found out the hard way that being open to all volunteers leads to things going wrong. We also think 5 ropes is the minimum for this length of hoophouse. We plan to have 7 next time. We value having a spotter inside the hoophouse to push up on any jammed tennis balls, and a spotter on the south side (outside), who can see progress with the outer layer going up and call to individuals to pull more or pause, so that the plastic goes up evenly.
New inner plastic being pulled up and over the frame. Wren Vile
We had some trouble with the outer layer snagging, and speculated that it might be because our frame does not have a ridge pole, just two high purlins. The tennis ball lingered in the saggy bit of plastic too much. I also think we could practice smoother knots, to reduce the chance of snags.
We ordered 48′ x 100′ Tufflite IV and Tufflite IR and PolyPatch tape for our 30′ x 96′ gothic-shaped tunnel from Nolts Greenhouse Supplies in PA. We use the wigglewire and aluminum channels (also called Polylock), which are reusable over and over.
Bucket of tools for setting wigglewires. Gabby Schulz
Tool List:
Tall stepladder and 2 pairs of shorter stepladders
For a 30′ x 96′ tunnel, at least 8 rolls of high quality Gorilla tape. Stinginess doesn’t pay.
Tools for each person: pliers, soup spoon, flat-bladed screwdriver, scissors.
Utility knives to trim the plastic when it’s on right. Bolt cutters (for the wigglewire)
Tennis balls and ropes to pull the edge of the plastic over the top. At least 5 sets for a 96′ house. Use ropes long enough to go over to the other side – say 5′ longer than the width of your plastic.
A sock and a plastic water bottle (to attach to the throwing end of the rope)
Polypatch tape and scissors. Accidents will happen. Try to be gracious and forgiving!
Bed Prep continued alongside renovations. Notice taped frame connectors on left, not yet taped on right. Raen Thornberry
Focus Cover Crops for October: Winter Wheat and Austrian Winter Peas
In August I wrote about cover crops such as millets, southern peas, buckwheat which are frost-killed. For most of us in the mid-Atlantic, it’s too late for those.
October is too late to sow winter-killed cover crops in central Virginia
Our average first frost is October 14-20. If yours is later, and you still have 40-60 days to your average first frost, you can still 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, the cut-off date for oats is 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.
Oats winterkill completely at 6°F (-17°C) or three nights at 20°F (-7°C. Fall-sown barley (Hordeum vulgare), grows even faster than oats, and dies at 17°F (-8°C).
There are still three weeks here when it is worthwhile to sow cover crops (up to a month past first frost), and I’m going to write about those here.
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. Once we’ve reached mid-October, this is no longer an issue here.
Winter rye cover crop headed up in early May. Photo Pam Dawling
Winter-hardy grass cover crops to sow in October
Winter rye and winter wheat can be sown in the mid-Atlantic in October. Wheat has less of an allelopathic effect on small seeds, the inhibition of germination that lasts three weeks after rye is turned under. 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, allowing us to make faster use of those plots in the spring, compared to plots sown to rye.
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.
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.
For us wheat is a good, trouble-free winter cover crop. The later it gets towards our cover crop cutoff date of November 15, the more likely we are to choose rye. Also, of course, if we have already used all our wheat seed! Winter rye is hardier than any other cover crop and can take later planting dates. More about Last Chance Cover Crop next month. Then I will also write about how to protect the soil over the winter if it is bare.
Secondary cover crops in October: Include legumes where possible
See my September post for more about the benefits of including legumes with winter cover crops grasses. Also how to inoculate legume seeds with the nitrogen-fixing bacteria. See Working with the time you have leftfor options if you are in another climate zone.
Another key to success with fall sown legumes is to sow early enough to establish before winter halts growth, and to plan not to need that plot next year until flowering time for that legume. 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. Crimson clover flowers in central Virginia 4/16-5/2, most usually around 4/20. Austrian winter peas bloom at the end of April, and hairy vetch in early May.
October 15 (our average frost date) is our clover/peas watershed (legume-shed?). Before that date we use crimson clover; after it (until 11/8, 3 weeks after our average frost date) we sow Austrian Winter Peas, along with winter rye or winter wheat.
Austrian winter peas can be sown later than other legumes.
Hardy type of Field Pea. (Black peas)
Winter-kill in zone 6, hardy in zone 7. Hardy to 0°F (-18°C). (Canadian/spring field peas are hardy to 10-20°F (-12° to -7°C))
Can sow several weeks later than clovers
Sow at least 35 days before first hard freeze (25°F/-4°C). In zone 7a, 8/10–11/8
Optimum temperature for germination is 75°F (24°C), minimum germination temperature 41°F (5°C)
Good at emerging through crusted soil
Tolerate a wide range of soil types
Make rapid spring growth in cool weather
Suppress weeds, prevent erosion
High N-fixers – a good stand can provide enough N for the following food crop when incorporated
They fix as much, or more, nitrogen than crimson clover
More dry matter than hairy vetch (which produces more than crimson clover) in the SE
Can be mixed with grasses for vertical support, more biomass and better weed suppression
Suppresses Septoria leaf spot in tomato crops the next year
Blooms late April at Twin Oaks, before hairy vetch
Flowers attract beneficial insects (especially honeybees) and reduce aphids
The tendrils and shoot tips make a nice addition to salads or stir-fries in early spring
Winter rye with Austrian Winter Peas. Photo Cindy Conner
Cautions with Austrian winter peas
Pea seed cannot be stored long. The germination rate could be only 50% after 2 years. Run a germination test if you have seed you are unsure about.
Seeds are large and heavy – high sowing rates (compared to clovers). Cost/area is fairly high, a little higher than vetches
If you haven’t grown peas or beans on that plot for some years, inoculate the seed.
Winter-killed in zone 6, at 0°F (-18°C). For the best chance of winter survival in cold areas, choose your sowing date to get plants 6-8″ (15-20 cm) tall before the soil freezes. (Hairy vetch is more cold-tolerant than AWP.)
Sowing in a mix with a winter grain will improve cold weather survival by reducing soil freezing and heaving.
May not do well if sown in spring – require a cold dormant spell.
Not tolerant of flooding, drought, high traffic, salinity, heavy shade, long cold spring weather below 18°F (-8°C) with no snow cover, or hot (or even warm) weather.
Do not regrow after mowing or grazing once blooming starts.
Peas on their own do not add much organic matter to the soil – the vines break down quickly.
May increase 39 species of pest nematodes, so if you are already having trouble with those, this is not a good cover crop for you.
Susceptible to Sclerotinia crown rot, which can completely destroy crops during winter in the mid-Atlantic. One reason not to grow pea crops on the same land two years running.
Can also be host to Sclerotinia minor, Fusarium root rot and Ascochyta
Cover of Managing Cover Crops Profitably book from SARE
More resources on Cover Crops
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.
Normally you could expect a “Cover Crops for the Month” post in the first week of the month, but October’s will be next week. I have been teaching at several events in middle Tennessee, and want to tell you about those, and include the slideshows for those that want a second look, or those who wish they had been there.
We had a day and a half at Jeff Poppen’s 250 acre Long Hungry Creek Farm, where a very laid back outdoor Southeast Regional Biodynamic Farming Conference was going on. It’s in Red Boiling Springs, TN. Jeff is also known as the Barefoot Farmer, for reasons that are obvious once you meet him. Jeff began making biodynamic preparations and using the biodynamic farming method in 1986. Jeff and colleagues ran a community-supported agriculture program from 1988-2022, and they have offered internship opportunities since 1997.
Jeff Poppen’s logo
Not all the participants practice biodynamics (I don’t), and the conference was quite eclectic. I gave a presentation about growing Asian Greens to a very lively, question-filled group. Here’s the slideshow:
Ira Wallace and I also hosted a Q&A session on Seed Saving and Community Living. We did answer two short questions about seed saving, but most of the interest was in community living. The questioners were thinking about cohousing, or cooperative farming, or intentional communities, and had very considered questions.
We stayed two nights in the eccentric historic Armour’s Hotel with many theme-decorated rooms. Mine was about Red Hats. Definitely an experience.
A room at the Armour’s Hotel, Red Boiling Springs. The hotel’s photo.
Then we went to the Nashville Food Project on Sunday. Nashville Food Project is a community food project that brings people together to grow, cook and share nourishing food. They do community gardens, food recovery and community meals including thousands of after-school meals for kids, meals for nursing homes and all sorts. They have a lovely building for meetings, meals, cooking and everything related.
In their gardens, they grow organic food intensively and share resources with others interested in growing their own food.
In their sparkling commercial kitchens, they use recovered, donated and garden-grown food to prepare and cook made-from-scratch meals. Donations come from farmers, grocers, restaurants and markets. 1 in 7 Nashvillians do not have access to the food they want and need. Currently 40% of all food produced in the USA is thrown away. This knowledge drives the Nashville Food Project to continually explore new ways to recover would-be wasted food and steward it toward its best and highest use… and what better use for food than to feed neighbors!In their community, they share nourishing meals in partnership with local poverty-disrupting nonprofits and community groups.
We stayed two nights with Dr Brenda Butka and her husband Dr Tom John, who were very welcoming hosts.They are founding members of the Bell’s Bend Organic Farms Conservation Corridor. Bells Bend Conservation Corridor’s mission is to promote and protect the rural character of the Bells Bend. (It’s within the city limits, and yet has never been built on.) They are working to establish an outdoor recreational, agricultural, and residential conservation district that serves as a county, state and regional planning model for open space preservation.
They are raising money to provide funding to individual land owners seeking conservation easements from the Land Trust for Tennessee. While developing and funding programs that promote farm education, environmental stewardship, and the importance of land preservation. They currently have over 350 acres in Tennessee Land Trust Conservation Easements.
On Monday, I spoke to the Women Farmers of Middle Tennessee at Old School Farm, where a Scottish philanthropist bought and renovated an abandoned school house and set up a non-profit farm employing people with disabilities.
They work together with MillarRich, a healthcare company that specializes in providing family-style foster careand employment services for adults and children with intellectual and developmental disabilities. They also work with The Store which operates a year-round free grocery store allowing people referred to them (and the referring agencies) to shop for their basic needs at no charge. They may shop for food to supplement their income during times of crisis and as they work toward self-sufficiency.
I gave a presentation for the Women Farmers of Middle Tennessee on Production Planning for Late Fall, Winter and Early Spring Vegetable Crops. Here’s the slideshow:
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
USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture. Accessed from https://planthardiness.ars.usda.gov/. Click the link for access to state and regional interactive maps.
Zones 10 and 11 were added in 2012, and Zones 12 and 13 are added to the new 2023 map. Zones 12 and 13 are presently only found in Hawaii and Puerto Rico, where the average annual minimum temperatures are above 50°F (10°C) and 60°F (15°C) respectively. The new interactive map has closer definition between neighboring areas than previously, and can be examined at a finer scale. A city or town with heat-absorbing concrete, can be seen as warmer than surrounding countryside.
In 
