Solarization of our whole hoophouse

 

Solarization plastic spread across our hoophouse. Next we weighted down the edges with small buckets of rocks. Photo Ken Bezilla

I wrote in August 2019 about Solarization and Crop Choices to Fight Nematodes. Previously we solarized part of a bed in our hoophouse, or one or two beds. I’ve written before about our first efforts at solarization to fight root knot nematodes in our hoophouse. Back then we shoveled soil on the plastic edges to make a good seal between the plastic and the soil. Later we developed a good technique of pushing the plastic edges down into soil using spades, which gives a much better seal, and if you work both sides of the bed at the same time you can avoid wrinkles.

Solarizing a single bed in 2019 using a spade to push the plastic edge into the soil..
Photo Pam Dawling

This summer we decided to solarize the whole hoophouse. We hope to make progress on reducing fungal diseases in our winter crops, drawing down the weed seed bank, and killing lots of nematodes. We plan to solarize for the whole of August (4 weeks). Here’s the story so far.

Solarization

Solarization is a method of killing pests, diseases and weed seeds near the surface of the soil by covering the soil with clear plastic in hot weather. Nematodes are only active in warm weather, and we have not had problems with them outdoors, but of course, it’s warmer in the hoophouse!

In my Book Review: The Organic No-Till Farming Revolution: High Production Methods for Small-Scale Farmers, Andrew Mefferd, I wrote a little about solarizing:

“Solarization uses clear plastic (old hoophouse plastic is ideal). In a summer hoophouse, solarization can be as quick as 24 hours, Andrew says. When we’ve done this, one of our goals was to kill nematodes and fungal diseases, not just weeds, so we waited a few weeks. Outdoors it takes several weeks. You can see when the weeds are dead. Bryan O’Hara poked a thermometer probe through solarization plastic and found a 50F degree (28C) difference between the outside air and the soil immediately under the plastic; a 10F (6C) difference at 1″(2.5 cm) deep and little temperature gain lower than that. Solarization does not kill all the soil life!”

Preparation for Solarizing

Last time we changed the plastic, we saved our old hoophouse plastic in one large sheet, for just this option of solarizing the whole hoophouse. Unfortunately, someone used it for some other purpose, and we ended up having to buy new plastic to carry out our plan. Ouch! Label your old plastic very thoroughly! We bought 4 mil Tufflite Nursery Clear plastic from Nolts Greenhouse Supplies, Ephrata, PA (only rated for one year outdoors), thinner than the 6mil we buy for covering the frame. Be aware that shipping can be a big part of the cost, unless you are ordering lots of things.

Clearing hoophouse tomatoes and sunn hemp cover crop.
Photo Pam Dawling

We pulled up our tomatoes and cucumbers at the end of July, a week earlier than usual. The squash had already gone. I was sad to say goodbye to the bell peppers as they were the best we’ve had in years. Usually we keep the peppers until October and do our winter crop planning so that the pepper area is the last planted in winter crops, but we made that sacrifice! For several years our peppers didn’t do well, as the salinity of our soil had got too high. We now do salt wash-downs in September and March. This year they were spectacular! Big plants, huge peppers!

Lady Bell peppers ripening on 7 July.
Photo Pam Dawling

We decided to keep the big shadecloth in place for the solarizing day, expecting it to be very hot. It wasn’t, but it was a wise precaution. We planned to remove the shadecloth the next day, but it was raining and we need the shadecloth to be dry to pack it away. So we waited a couple of days for our little monsoon season to pass. Normally we leave the shadecloth in place until mid-September or so, but this year we want maximum heating for the solarization.

We are leaving the drip tape in place so we can water the soil and keep it alive below the hot zone. If we had thought of it in time, we might have spread compost on the beds before spreading the plastic and killed the weed seeds that have landed on the compost pile while we ignored it since early April. We were stretched thin and got behind with the mowing, and we know grass and spiny amaranth seeded somewhat on to the pile. We did have it partly covered with a tarp.

Unrolling the Plastic

Unrolling plastic to solarize the hoophouse.
Photo Pam Dawling

We bought plastic 32’x100’ which was just right for the footprint of our 30’x 96’ gothic hoophouse. We unrolled it down the center bed (it was folded in several concertina folds from each edge to the middle). We gradually unpacked the folds and pulled the plastic out to the edges. It is important to get as smooth and tight a fit as possible (few airgaps between soil and plastic).

We designated one person to take their sandals off and walk on top of the plastic, while the rest of us gathered small buckets and put some rocks in them, to anchor the edges. This all went very smoothly and took less time than we expected. We used about one bucket of rocks every 20’ down the length. We rolled our painters’ pole that we use for our SnoBrum in the plastic across the west doorway, the direction the strongest winds come from, for add extra security in preventing wind getting under that edge of the plastic. We did not bury the plastic edges in the soil, as that seemed difficult and we figured a large area would suffer less edge cooling/heat escape than a single bed.

Closing Up the Hoophouse for a Month

We closed the doors and windows and relaxed into enjoying a summer month off from harvesting in the hoophouse. We have made a list of infrastructure repairs, landscape care and, of course, the winter crop planning to do in t he next month. And we’ll be irrigating maybe twice a week and checking the soil thermometer periodically. It showed 80F last week, before we solarized.

Hoophouse solarization at Dripping Springs Garden, Arkansas.
Photo Pam Dawling

More Resources on Solarizing

eOrganic’s Organic Vegetable Production Systems Topics list offers publications on plant disease management, weed management and management of soil-borne pathogens using Anaerobic Soil Disinfestation. Here’s a 2025 webinar about On-farm Anaerobic Soil Disinfestation for the Management of Soilborne Pathogens in High Tunnel Production Systems:

 

https://www.youtube.com/watch?v=2pEf26ae6XI

The University of California Solarization site and their Small and Organic Farm Advisor have good information, including some in Spanish and Hmong

More Resources on Nematodes

I’ve written here before about our struggles with root knot nematodes in our hoophouse, and you can read everything I know about nematodes in the Year-Round Hoophouse.

My article on nematodes in Growing for Market  in November 2014 describes our discovery of the beasties and our first attempts to deal with them. My most thorough blogpost about nematodes was for Mother Earth News  Managing Nematodes in the Hoophouse. It’s free for MEN members.

There is info on dealing with nematodes from Garry Ross in Hawaii, where nematodes are a fact of daily life, in my post Cold weather, snow, thinking about nematodes from February 2015.

Unusual Crop for August: Kohlrabi

Harvested kohlrabi, Early White Vienna and Early Purple Vienna.
Photo McCune Porter

Unusual Crop for August: Kohlrabi

 In May I wrote about Peanuts

In June I wrote about Bug-Resistant Summer Squash Substitutes

In July I wrote about Squash Blossoms and Other Edible Flowers

Much of this information comes from my book Sustainable Market Farming 2nd Edition.

This month, I’m writing about kohlrabi, an eye-catching and very storable brassica crop. Kohlrabi can be grown in central Virginia where I live in spring and in fall. In cooler climates it can be grown in summer, and in warmer ones through the winter. The winter-kill temperature for kohlrabi grown in the open, with no protection, is 15°F (–9.5°C), similar to red chard, Russian kales, and some varieties of beet, broccoli, cabbage. Kohlrabi production is like that of other brassicas, and the methods of cultivation and harvesting are very similar.

Kohlrabi is an unusual crop that is sure to attract attention at your market booth or be a discussion piece in CSA bags, in your garden and on your table. It is a swollen stem base, with leaves individually sprouting from the globe. When the tap root and leaves are trimmed off, it resembles a sputnik (the first manufactured Earth satellite, in 1957). It is tender and crunchy with a flavor between a cabbage and a turnip. It’s easy to grow and doesn’t wilt as soon as you harvest it. It can be eaten raw (sliced or grated) or cooked, and the leaves can also be cooked and eaten. It stores well, offering flexibility about when it is eaten or sold, which is always an advantage for growers.

Kohlrabi can be direct sown or transplanted, whichever suits you best.

Kohlrabi Crop Requirements

Brassicas grow best on fertile well-drained soil with adequate moisture. They require a lot of potassium, so a sprinkling of wood ash, kelp meal, or granite dust could be helpful if your soil is a bit short of potassium. Calcium, boron, iron, manganese, and molybdenum are also important for good brassica crops – healthy, biologically active soils can usually supply enough of all these. If not, amend as needed. Optimal growing temperatures for most brassicas are 60°F–65°F (15°C–18°C).

Green kohlrabi.
Photo Small Farm Central/Harvie

Cover Crops before Fall Kohlrabi

Because fall brassicas are transplanted in summer, it’s possible to grow another vegetable crop, or some good cover crops, earlier in the year. An overwintered cover crop mix of winter rye and crimson clover or hairy vetch could be disked in at flowering and followed by a short- term warm-weather cover such as buckwheat, soy, or southern peas, all before the fall kohlrabi. A spring-sown cover crop mix of bell beans (favas), barley, and oats does well before all fall brassicas at Roxbury Farm in New York, supplying all the nitrogen required by the brassicas, which are heavy nitrogen consumers. To minimize pests and diseases, don’t use brassica cover crops.

Rotations Including Brassicas

A rotation of 1 year in 4 is ideal for brassicas to avoid disease and pest buildup. When possible, plant one year’s brassicas at some distance from the previous year’s, rather than in adjacent plots. The spread of disease can be reduced by avoiding walking through wet crops and by controlling weeds in the brassica family, such as rock cress, pepperweed, garlic mustard, and wild rocket.

We always plant our kohlrabi in permanent raised beds as we cultivate these with a BCS walk-behind tiller and can work them a bit sooner than the flat fields, where we must wait for the soil to dry enough to use the tractor and disks.

Kohlrabi Varieties

Interest in kohlrabi is growing.I’m encouraged to see that Johnny’s now sells 7 varieties, Fedco has five, Baker Creek has 6 and High Mowing has 8!

We like the open-pollinated Early White Vienna and Early Purple Vienna (58 days from sowing) and the purple hybrid Kolibri (45 days), which is more expensive but beautiful, quick-growing, and uniform. Purple varieties seem slightly more resistant to cabbage worm and also less susceptible to cracking. A mixture of the white (green) and purple colors looks very attractive, and they’re both white under the skin, so our strategy is to grow 25%–35% purple and mix them in; 4 g = about 1,275 seeds, sows 135′ (41 m). 5,500–9,000 (avg. 6,500) seeds/oz, (200–320, average 230 seeds/g).

Superschmelz kohlrabi (60 days from transplanting) can also be summer sown for fall harvest. It produces 8″–10″ (20–25 cm) bulbs, which are an attractive globe shape and remain tender. The world record (variety not disclosed) weighed almost 97 lbs (44 kg), leaves included.

Kossak (80d to maturity) is a good storage variety that maintains its sweet, delicious, and tender dense white flesh in storage for 2–4 months.

The other type of kohlrabi is the slower-growing giant winter storage variety, such as Gigante (130 days from sowing in spring for late fall harvest). It regularly exceeds 10″ (25 cm) in diameter and 10 lbs (4.5 kg) in weight. Gigante’s crisp, white, mildly tangy flesh doesn’t get woody even when it gets enormous.

A September sowing of kohlrabi. Too late in the year to thin and grow to full-size, kohlrabi makes good salad and microgreens. Photo Bridget Aleshire

How Much Kohlrabi to Grow

We grow 360 row feet (110 m) of fall kohlrabi for a hundred people. We sow in mid-late July, and transplant around July 29–August 12 at 8″ (20 cm) apart in the row, with 9″–10″ (23–25 cm) between rows – 4 rows in a 48″ (1.2 m) wide bed. If direct sowing, you could sow in drills or in stations (groups of several seeds sown at the final crop spacing).

Systems for Growing Kohlrabi Transplants

The same systems you use for growing transplants in spring may also work well for fall: flats, cell-packs, outdoor nursery beds. We use an outdoor nursery seedbed and bare-root transplants because this suits us best. The nursery bed is near our daily work area so we’ll pass by and water it. (Our greenhouse is off to one side of our gardens.) We’re always relieved to close the greenhouse transplant season in May, as we no longer need to water little plants many times each day to keep them alive. Having the seedlings directly in the soil drought-proofs them to some extent; they can form deep roots and don’t dry out so fast.

Other people manage fine with flats in June and July, but we avoid it. If you use flats, it can help to have them on benches in an enclosed shadehouse, or outdoors, above the height of flea beetles. Ira Wallace of Southern Exposure Seed Exchange tells me 3′ (1 m) is high enough. Richard Jones, in his book Beetles, says flea beetles can jump at least 100 times their body length.

For our seedbeds, we use insect netting (ProtekNet) on wire hoops. In warm weather, I prefer netting against bugs because it lets in lots of air. Rowcover also protects against bugs, but provides less airflow, which can make the seedlings more likely to die of fungal diseases in hot weather.

Kohlrabi is a less-common brassica. This is Early Purple Vienna. Photo Kathryn Simmons

Germination of Kohlrabi Seeds

The most challenging part of producing fall brassicas is getting the seedlings growing well while the weather is hot. Unlike some cool-weather vegetables such as spinach, brassicas will germinate very well at high temperatures: the ideal is 77°F–85°F (25°C–29°C), but up to 95°F (35°C) works. Given enough water, summer seedlings will emerge in only 3 days. Once they have emerged, the challenge begins. As well as temperature and moisture in the right ranges, the seedlings need light (very plentiful in midsummer!), nutrients, good air-flow, and protection from bugs. Guarding the plants from bugs is the most challenging for us. We deal organically with flea beetles, harlequin bugs, and, sometimes, cabbage worms. Our main defenses are farmscaping and insect netting.

Search my previous posts for more on pest control. Brassica pests seem less interested in kohlrabi than in other brassicas, and as people are less likely to eat the leaves, there is room to tolerate a certain number of leaf-eating pests, while still having an attractive crop and a high enough yield.

“No visible brassicas” month

In an attempt to break the relentless lifecycle of the harlequin bugs, we now try to have a month from late June to late July with no brassicas visible in our garden. We make sure to mow down the spring broccoli trunks, the kale, and collards and harvest or pull up any other brassicas. We net new transplants and remove the netting a month later, allowing us to hoe and weed.

Brassica seedlings under Proteknet.
Photo by Bridget Aleshire

Timing for Fall Kohlrabi

Planting dates for fall crops can be exacting because the cooling weather slows down the plants’ growth, and a day or two delay in sowing date can mean a week or two delay in harvest date. Although it can be hard to think about sowing seeds in midsummer, it’s very worthwhile because brassicas develop delicious flavors as they mature in the cooler fall days,. Weeds and pests slow down then, too – once established these crops need little care.

The number of days to harvest given in seed catalogs is based on spring conditions – plants grow faster in warmer temperatures. To determine when to sow for fall plantings, start with your desired harvest date (noting when would be too late!), then subtract the number of days from seeding to transplant (21–28), plus the number of days from transplanting to harvest for that variety (given in the catalog description), plus the length of your ideal harvest period and another 14 days for the slowing rate of plant growth in fall compared to spring.

Example: Early White Vienna Kohlrabi, 58 days from sowing to harvest in ideal weather.

  • Consult https://weatherspark.com to estimate when it will get too cold in your location to leave kohlrabi in the ground. Here, in winter-hardiness zone 7a, our average annual minimum temp is 0°F-5°F (-15°C to -17.7°C), although most winters don’t reach those temperatures for very long. Our average winter low is about 25°F – 32°F (-4°C to 0°C).
  • Kohlrabi is hardy to 15°F (–9.4°C). The temperature is not likely to drop to 15°F (-9.4°C) before the beginning of December here.
  • Adding 40% more time, allowing 80 days, we could sow kohlrabi in early August and get a crop at the end of October.
  • Or mid-August for early November.
  • Or early September for the end of November or very beginning of December.
  • If you sow too late, use the seedlings for salad. Kohlrabi also makes a good microgreens crop.

Sowing Kohlrabi Seeds

Our rough formula for all transplanted fall brassicas is to divide our final crop row length by our in-row plant spacing and then sow extra to be sure of having enough good ones on transplant day. For kohlrabi to be planted 8″ (20cm) apart, to plant 360’ (110 m) we’ll need 540 perfectly lovely transplants.

We aim to sow 3 seeds/inch (1 cm apart). We make two sowings one week apart, to ensure we have enough plants of the right size. Each week after the first sowing, we weed the previously sown plants, and thin them to 1″ (2.5 cm) apart. We resow to make up the numbers if germination is low.

Young kohlrabi plants.
Photo Kathryn Simmons

Transplanting Kohlrabi

We aim to transplant most brassicas at four true leaves (3–4 weeks after sowing). It is better to transplant crops at a younger age in hot weather than you would in spring because larger plants can wilt from high transpiration losses. If we find ourselves transplanting older plants, we remove a couple of the older leaves to reduce these losses.

We transplant in late afternoon or early evening. We water the soil in the plot if it is dry, because it is very important at this time of year to get adequate water to the plants undergoing the stress of being transplanted. Likewise, good transplanting technique is vital. With drip irrigation, you can more easily give a little water in the middle of each day, which will help cool the roots. With only overhead sprinklers, you may not have the option of watering every day.

Bed of young kohlrabi. Kathryn Simmons

Kohlrabi Harvest

Harvest storage kohlrabi while the anchor (tap) root is still round, before it begins to elongate. We harvest our Vienna kohlrabi from October 20 to November 15. For storage cut off the tuft of leaves at the top of the plant and also the wiry root. It’s easiest to cut a disc off the bulb rather than try to cut through at the point between the bulb and the wire, where it is very tough.

Kohlrabi Winter Storage 

Kohlrabi can be stored in a refrigerator or refrigerator-like conditions such as a CoolBot, 32°F–40°F (0°C–5°C), 80%–95% humidity. Basically Cold & Moist. Kohlrabi stores well in perforated plastic bags in a walk-in cooler. In a plentiful year, we have eaten stored kohlrabi throughout the winter into early spring.

Front cover of Beyond the Root Cellar book by Sam Knapp
Cover of Beyond the Root Cellar by Sam Knapp

 

A Few More Good Resources for Storage Information

Book Review: Africulture by Michael Carter Jr


Africulture: How the Principles, Practices, Plants and People of African Descent have Shaped Agriculture

by Michael Carter Jr. Chelsea Green, 2026. 308 pages, $22.95 US, $40.00 CAN, 22.95 GBP.

As a fellow Virginian, I am honored to offer praise for Michael Carter’s new book, Africulture.  I enjoyed his account of his family’s farming history. Mr. Carter shares five generations of Black farming experience and reminds those of us who need reminding, that without African farming experience, white immigrants like me would not have survived long in the American colonies.

With inspiring bios of prominent Black farmers and educators, Africulture presents an uplifting message and encouragement to other farmers, especially Black farmers. I value Mr Carter’s work to preserve civil rights, and his determination to raise awareness of the painful history of Black people in the US, including segregation, Jim Crow, lynching and resistance. I learned a lot more Black history from reading this book. I’m not including it in this review as I imagine many of you already know a lot more than I do about that.

Mr Carter tells us: “The average age of a farmer in Virginia is fifty-nine, but for Black farmers it’s sixty-three. Between 2017 and 2022, Virginia lost 10 percent of its farmers and 20 percent of its Black farmers. The state is losing Black producers at a higher rate than any other demographic.”

“The amount of land lost by Black farmers and families in the last sixty years is, I dare say, a sin to our ancestors who made it their sole mission to acquire land between 1865 and 1965. I’m a benefactor of my ancestors’ efforts and I refuse to let go of what was sacrificed by my grandfather and his brothers with their World War II checks.”

He writes in a very lively, readable style, using stages of plant growth: Seeds, Soil, Roots, Compost, Leaves, True Leaves, Pestilence and Resistance (plants and people), Flowering, Fruit as metaphors of Black farming history. His work includes Principles of Africulture, using limited inputs: reuse materials your farm provides, properly dispose of whatever waste ends up on your hands; use sustainable organic practices, co-operate on marketing and training, and strengthen future generations of Black farmers.

The Carter Family in Ghana

Michael Carter and his immediate family spent 5 years living and working in west African countries, especially Ghana, 2012-2017, before returning to his family’s farm in Virginia. Living in Ghana changed the Carter family’s perspective. The Carters were regarded factually, as obroni, people from the horizon, or white men. Skin color was not seen as the major identifier, but foreignness was.

Vegetables and fruits were bought fresh daily, and cooking dinner required full attention, dedication and love. There were lots of leafy greens, including Nigerian spinach (Celosia argentea), gboma (Solanum macrocarpon) (the g is silent), Alefe (Amaranthus cruentus), nkotomere (cocoyam leaf/taro leaf /elephant ear, Colocasia esculenta), water leaf/boko boko/fame flower (Talinum paniculatum) and ayoyo/jute leaf (Corchorus olitorius), which I wrote about in June 2025 as Molokhia (pronounced “mo-lo-HEY-ah”), Egyptian Spinach.

The Ghanaians have a very well-developed understanding of the medicinal value of plants.

Food Crops from Africa

From May to September the Virginia climate is like the rainy season in West Africa. I appreciate the descriptions of tasty African crops that might be useful in central Virginia for climate change resilience. To grow Ghanaian crops, we need to choose those with shorter growing cycles. Our season is too short for the tree crops or annuals needing 6-9 hot months to maturity.

Virginia can grow amaranth, Nigerian spinach, managu, molokhia, okra, sorghum, millet and cocoyam, all sown in the continental US after Mothers’ Day, the second weekend in May. Soil temperatures should be 70°F-75°F (21°C–24°C). Their roots grow deep, enabling them to be drought tolerant, and helping provide more trace minerals. A bonus is that deer don’t seem to like these greens.

Several African greens also have ornamental relatives, but the green-leaved versions are preferred for eating. I don’t know why. The greens need to be stewed well over a high heat with palm oil and egusi (seeds of specific melons). Taro tubers and leaves need careful cooking.

“Two African crops—sweet potato greens and Nigerian spinach—contain some of the same nutrients as kale, but they are dependent more on the fungal network to supply their nutrient needs. Their content of manganese and some other micronutrients is higher than that of kale.” Clif Slade says, on selling the leaves of sweet potato plants: “You can talk about doubling your money. . .  There’s $20,000 per acre in the [sweet potato] leaves with the right market, and eating them can help control blood pressure.  Large amounts of sweet potato leaves can be fed to livestock. And at Virginia Tech, they’re pelletizing the stems and feeding tilapia.”

First Leaves

The “First Leaves” chapter has information on rice, cotton, indigo, peanuts, cocoa, vanilla, coffee, honey and kola, and several leading Black farmers. It was here I learned more about my “sweet potato hero” Dr George Washington Carver. I immigrated from a climate too cold to grow sweet potatoes, so I knew nothing. This was pre-internet, and I was thrilled to find a photocopy of Dr Carver’s 1936 publication “How the Farmer Can Save His Sweet Potatoes, and [32] Ways of Preparing Them for The Table.” I had not understood properly how to cure sweet potatoes before storing them. Gratitude to Dr Carver! Dr Carver was even more famous for his work with peanuts. Did you know that boiling peanuts preserves them for several days without refrigeration?

Dr Carver also designed a mobile demonstration lab called the Jessop Wagon, which was used to take information out to remote rural areas of Alabama and provide information for farmers. He wrote “It has always been the one ideal of my life to be of the greatest good to the greatest number of my people possible, and to this end I have been preparing myself for these many years, feeling as I do that this line of education is the key.”

Dr Booker T Washington was born into slavery in 1854 and walked 500 miles to enroll in the Hampton Institute in SE Virginia at the age of 16. His dedication to education, community building and Pan-Africanism was huge. Dr Washington became the first principal of Tuskegee University in Alabama, where the students and local community hand built the collage, including making the bricks, sewing their own sheets and growing their own food.

Dr W E B Du Bois wanted the Talented Tenth, the most capable Black students, to receive the best education and so serve as a think tank and group of leaders for the Black community. He is more widely known as a highbrow intellectual rather than a rural pragmatist like Dr Carver and Dr Washington. Later he developed a wider understanding of the needs of Black farmers.

Mr Tetteh Quarshie, a Ghanaian blacksmith, established the commercial cocoa industry in Ghana in 1879, and export began in the 1890s. Cocoa is native to central America, and became cultivated in Africa, especially Ghana, in the early-mid-1800s.

Vanilla was much coveted by the Europeans, who had no success getting it to grow. 300 years later, someone figured out that a very specific pollinating bee that was only found in Mexico was needed. The French shipped seeds to their colonies off the coast of Africa, Réunion and Mauritius. 21 years later, a 12-year-old enslaved African boy, Edmond Albius, used hand pollination, smashing the anther sac and stigma together between his fingers, solving the problem.

Watermelon was one of the best cash crops for Black farmers in the South, easy to grow, easy to transport, kept well in its skin. This superfood is a great hydrator and a nutritional powerhouse. But watermelon was heavily denigrated as poor people’s food, and disrespected, cast as bad, backward, food for country bumpkins.

Our Genes are Made of What our Ancestors Ate.

African crops grown in American soil by enslaved Africans with African expertise helped sustain the colonizing immigrants. Our bodies are made of the food we eat. Our lineage reflects the foods of our ancestors, which may have come from other continents.

Three quarters of the British colony of Jamestown died of disease and malnutrition between 1609-1610, despite eating rats, snakes and their own dead neighbors. They had refused to follow local foodways, instead trying to grow cool weather UK crops. White settlers in 1619, when the white population had been reduced to 12% of its size, decided they would need to enslave Black people to grow their food. Some of the enslaved people arrived with leftover food stores, and the African crops grew well in the SE US, but in the Midwest, 50 years of soil mismanagement led to the Dust Bowl. Ignorance and greed destroyed 6 feet (2m) of topsoil.

Racial Equity

Equity is not just about perceived treatment but includes discussions and ideas around shared ownership and control of resources. White European men have determined what resources they want and how to get them and control them. Financial equity is the value of an asset after the cost (debts, liabilities) have been subtracted. Equity depends on ownership and is a store of financial value. Social equity (including racial equity) is defined as justice, fairness and impartiality. It’s also a store of value for people, ownership in communities, controlling resources (not necessarily owning).

Black people sometimes risk their jobs, homes, freedom, even their lives, when dealing with white people. White people need to face being outside their comfort zone, to become educated in other cultures. This book seeks to improve people’s racial literacy around the bigger history of agriculture. Buy from local Black farmers and local Black businesses, and other enterprises of people of color.

The Fruits of the Ancestors, Legacy and the Future

Fruit is both the fulfillment of the plant’s growth and the container of the seeds to start the cycle again. A responsibility and a survival instinct. Plants share resources in the soil. When someone asks for help, try to give them a hand. Mr Carter gives space in his book for soil brothers and soil sisters.

Carter Farms and the Africulture non-profit

The Carter Farms land, purchased in 1910, was almost lost near the end of the 1920s, when it was used as collateral on a $636.40 debt. The stock market crash of 1929 meant the borrowers could not repay the cash. Of the ten siblings in that generation, Mrs Mattie Shirley Carter Pryor, one of the youngest, great-grandmother to Michael Carter Jr, was the key person who saved the land.

Michael Carter Jr went to North Carolina Agricultural and Technical State University, an HBCU, where students were encouraged towards employment in the USDA or the agriculture industry, not to be farmers. Carter was not interested in being a farmer. He was more interested in his minor, fashion design. It was many years before he regained his connection to the land.

When Mr Carter and his family returned from Ghana in 2017, he combined a job at the Virginia State University Small Farms Outreach program with selling African vegetables to restaurants.  He established the non-profit Africulture to focus on “the principles, practices, plants and people of African descent that have contributed to agriculture.

From Carter Farms in Orange County, Virginia, Michael Carter, Jr provides technical farming assistance, events and workshops on growing and marketing African and other specialty vegetables. The land around Carter Farms became an epicenter of Black landownership and cooperative economics, farmers helping each other buy land.

“Africulture became an official nonprofit in 2020. Small farmers found themselves in a unique situation that spring because of COVID-19. Small farmers across the country became a lifesaving force for families and communities, setting up farmers markets and driveway stands where customers could come and pick up produce, proteins, and value-added products during a time when entering a grocery store felt dangerous.”

Carter says “I wanted to use the Africulture platform to promote connections on many different levels. The African ideal that everything is connected always resonated with me, a stark contrast to the siloed, isolated, subjective thinking in most of the West. The connections among music, food, soil, agriculture, literature, meta- and quantum physics, nutrition, and mental health maybe aren’t normally seen, but they are made clear to me through my Africultural lens.”

Africulture appendices include a timeline of African American agriculture, incorporating that of the Carter family, some of whom arrived in the first generation of exiled Europeans reaching the US; a Carter Family Tree, with African, European and Native American roots; and a table of nutrient levels in crops at Carter Farms. There are chapter notes and a selected bibliography, and a 17-page index. There are 16 pages of color photos and several archival B&W images are seeded throughout.

More information

  • Michael Carter Jr has taught a course on Africulture at the University of Virginia.
  • The Black Family Land Trust (BFLT) based in Raleigh, NC, works as a conservation land trust, to keep Black families on their land in Virginia and several other states. “The Sixth Love Language – A Will.” Putting land in a family land trust can save a family from fighting. The Uniform Partition of Heirs Property Act 2020 helps prevent involuntary loss of family land.
  • Visit the Black Farmers Index (blackfarmersindex.com), the largest, FREE, most comprehensive directory of Black Farmers. The Index connects you to traditional and non-traditional growers, from row crop farmers, ranchers, vegetable and fruit producers to beekeepers, fisherfolk, foragers, vintners & more. There are 12 regional groups.
  • For those in Virginia, there’s also the VirginiaBlackFarmerdirecrtory.com.
  • Celebrate National Farmers’ Day in the US on October 12.
  • The Happily Natural Day Festival in Richmond, Virginia, is on Saturday Aug 29, 2026

Winter-Kill Temperatures of Cold-Hardy Vegetables 2025 revision

My scheduling program lost my post. Sorry. I won’t use that one again.

Here’s my table of winter-kill temperatures of cold-hardy vegetables (2025 revision). Not a lot has changed in the past year. This is the time of year to plan winter crops and even start them (apart from leeks and parsnips, which need sowing in spring).

I’ve added a few other resources people often want when planning winter crops: Four Ranges of Cold Hardiness; Rowcover Notes; Hoophouse Notes; Cold-Hardy Lettuce.

I compiled this as a handout to accompany my presentation for the Seedtime Winter Garden Challenge event.

Winter Garden Challenge Handout   

© Pam Dawling 2026.  Twin Oaks Community, Central Virginia (zone 7a)

Author of Sustainable Market Farming, 2nd edition and The Year-Round Hoophouse.

SustainableMarketFarming.com

Overwintered Acadia spinach, with weeds, March 16, Pam Dawling

Winter-Kill Temperatures of Cold-Hardy Vegetables 2025 revision

Here are some starting numbers of outdoor killing temperatures of unprotected crops (except where stated). Note that repeated cold temperatures can kill off crops that can survive a single dip to a low temperature, and that cold winds, or cold wet weather can destroy plants quicker than simple cold.  All greens do a lot better with protection against cold drying winds.  Your own experience with your soils, microclimates and rain levels may lead you to use different temperatures in your crop planning. This version includes cover crops.

  • 35°F (2°C): Basil
  • 32°F (0°C): Bush beans, cauliflower curds, corn, cucumbers, eggplant, lima beans, melons, okra, some pak choy, peanuts, peppers, potato vines, southern peas, squash vines, sweet potato vines, tomatoes.
  • 27°F (–3°C): Many cabbages, sugarloaf chicory (takes only light frosts)
  • 25°F (–4°C): Some cabbages, chervil, chicory roots for chicons and hearts, Chinese Napa cabbage (Blues), dill (Fernleaf), some fava beans (Windsor), annual fennel, some mustards and Asian greens (Red Giant, Southern Curled, maruba santoh, mizuna, most pak choy), some onion scallions (many varieties are hardier), radicchio, rhubarb stems and leaves.
  • 22°F (–6°C): Some arugula (some varieties are hardier), Bright Lights chard, some endive, large leaves of lettuce (protected hearts and small plants will survive colder temperatures).
  • 20°F (–7°C): Some beets (Bulls Blood, Chioggia), broccoli heads (maybe OK to 15°F/−9.5°C), some Brussels sprouts, some cabbages (the insides may still be good even if the outer leaves are damaged), celeriac, celtuce (stem lettuce), some collards (Georgia Cabbage Collards, variegated collards), some head lettuce, some mustards and Asian greens (Tendergreen, Tokyo bekana, Tyfon Holland greens), flat leaf parsley, radicchio (both Treviso and Chioggia), radishes (Cherry Belle), most turnips (Noir d’Hiver is the most cold-tolerant variety). Canadian (spring) field peas are hardy to 10-20°F (–12 to –7°C).

    Georgia Cabbage Collards Photo Southern Exposure Seed Exchange
  • Large oat plants will get serious cold damage, and oats seedlings die at 17°F (–8°C).
  • 15°F (–9.5°C): Some beets (Albina Verduna, Lutz Winterkeeper), beet greens, some broccoli, some cabbages (Kaitlin, Tribute), some cauliflower leaves, rowcovered celery (Ventura), red chard, cilantro, some fava beans (Aquadulce Claudia), Russian kales, kohlrabi, some lettuces (Marvel of Four Seasons, Rouge d’Hiver, Winter Density), especially small plants with 4–10 leaves, curly parsley, rutabagas (American Purple Top Yellow, Laurentian), broad leaf sorrel, most covered turnips, winter cress.
  • 12°F (–11°C): Some beets (Cylindra,), some broccoli, some Brussels sprouts, some cabbages (January King, Savoy types), carrots (Danvers, Oxheart), most collards, some fava beans (mostly cover crop varieties), garlic tops if fairly large, Koji greens, most fall or summer varieties of leeks (Lincoln, King Richard), large tops of potato onions, covered rutabagas, senposai leaves – the core of the plant may survive 10°F (–12°C), Purple Top turnips.
  • 10°F (–12°C): Covered beets, Purple Sprouting broccoli for spring harvest, a few cabbages (Deadon), green chard (hardier than other colors), some collards (Morris Heading), Belle Isle upland cress, some endive (Perfect, President), young bronze fennel, Blue Ridge kale, probably komatsuna, some leeks (American Flag, Jaune du Poiteau), some covered lettuce (Pirat, Red Salad Bowl, Salad Bowl, Sylvesta, Winter Marvel), covered Asian winter radish (Daikon, China Rose, Shunkyo Semi-Long survive 10°F/–12°C), big leaves of savoyed spinach (more hardy than flat leafed varieties), tatsoi, Yukina Savoy. Aprovecho Hardy turnip is hardy to 8°F (–13°C) and Ice-Bred White Egg is hardy to 6°F (–14°C), many Even’ Star greens varieties are OK down to 6°F (−14°C), Oats cover crop of a medium size die around 10°F (–12°C). Large oats will die completely at 6°F (–17°C) or even milder.

    Morris Heading collards.
    Photo Kathryn Simmons
  • 5°F (–15°C): Garlic tops even if small, some kale (Dazzling Blue, Winterbor, Westland Winter), some leeks (Bulgarian Giant, Tadorna), some unprotected small lettuces (Winter Marvel, Tango, North Pole, Green Forest), some bulb onions (Walla Walla), multiplier onions if not well-mulched, smaller leaves of savoyed spinach and broad leaf sorrel.
  • 0°F (–18°C): Chives, some collards (Blue Max, McCormack’s Green Glaze, Winner), corn salad (mâche), garlic, horseradish, Jerusalem artichokes, Even’ Star Ice-Bred Smooth Leaf kale, a few leeks (Alaska, Durabel), some bulb onions, mulched yellow potato onions, some onion scallions (Evergreen Hardy White, White Lisbon), parsnips (probably even colder), salad burnet, salsify, some spinach (Bloomsdale Savoy, Long Standing Bloomsdale, Olympia).
  • Walla Walla onions sown in late summer are said to be hardy down to –10°F (–23°C), but I don’t trust below 0°F (–18°C)
  • Crimson clover is hardy down to 0°F (–18°C) or perhaps as cold as –10°F (–23°C)

    Vates kale – our winter outdoor favorite.
    Photo Bridget Aleshire
  • –5°F (–19°C): Vates kale survives although some leaves may be too damaged to use. Lacinato Rainbow Mix kale may survive.
  • –10°F (–23°C) Austrian Winter Field Peas and Crimson clover (used as cover crops).
  • –15°F (-26°C) Hairy vetch cover crop – some say down to –30°F (–34°C)
  • –20°F (–29°C) Dutch White clover cover crops – or even –30°F (–34°C)
  • –30°F to –40°F (–34°C to –40°C): Narrow leaf sorrel, claytonia and some cabbages (January King) are said to be hardy in zone 3. I have no personal experience of this.
  • –40°F (–40°C) Winter wheat and winter rye (cover crops).

Four Ranges of Cold Hardiness

  1. Crops to harvest before frosty weather (32°-25°F) and use or store 
  2. Crops to keep alive in the ground into winter to 22°-15°F (-6°C to -9°C), then harvest to use or store.

Use Soon: Asian greens, broccoli, cabbage, chard, lettuce, radishes

Store: Beets, cabbage, carrots, celeriac, kohlrabi, winter radish (including daikon), rutabagas, turnips

  1. Hardy crops to store in the ground and harvest during the winter. In zone 7, they need to be hardy to 0°-10°F  (-17.8°C to -12.3°C): Collards, horseradish, Jerusalem artichokes, kale, leeks, parsnips, scallions, spinach
  2. Overwinter crops for spring/early summer harvests before the main season: Cabbage, carrots, chard, collards, garlic and garlic scallions, kale, multiplier onions (potato onions), scallions, spinach

    Garlic scallions in April.
    Photo Kathryn Simmons

Rowcover Notes

Rowcovers on hoops will help keep crops marketable, by improving the microclimate for better growth rate. Thick rowcover (Typar, 1,25 oz/sq yd) can keep crops 6F degrees, 3C degrees warmer. Hoops prevent crops freezing onto the rowcover. Polypro outlasts polyester. Consider Quick Hoops and caterpillar tunnels if they suit your climate and crops.

Closing rowcovers after a winter spinach harvest.
Photo Wren Vile

Hoophouse Notes

In a double-layer hoophouse (staying 8F/5C warmer than outside at night) plants can survive 14F/8C colder than they can outside, without extra rowcover; with thick rowcover (1.25 oz Typar/Xavan) at least 21F/12C colder than outside without. Salad greens in a hoophouse in zone 7 can survive nights with outdoor lows of 14°F (-10°C). Lettuce, mizuna, turnips, Russian kales, senposai, spinach, tatsoi, yukina savoy survived a hoophouse temperature of 10.4°F (-12°C) without rowcover, -2.2°F (-19°C) with; Bright Lights chard got frozen leaf stems. We only add rowcover when the outdoor low is forecast to be 8°F (–13°C) or lower.

Hoophouse mizuna harvest in January. Photo Wren Vile

Cold-Hardy Lettuce

Lettuce varieties for a solar-heated winter greenhouse or hoophouse in zone 7a: (hardiest are in bold) Buckley, Ezrilla, Green Forest, Green Star, Hampton, Hyper Red Rumple Waved, Marvel of Four Seasons, Merlot, New Red Fire, North Pole, Oscarde, Outredgeous, Pirat, Red Cross, Red Sails, Red Salad Bowl, Red Tinged Winter, Revolution, Rouge d’Hiver, Salad Bowl, Sylvesta, Tango, Winter Marvel, Winter Wonderland.

Lettuce Mix in our hoophouse 20 December. Photo Pam Dawling

Particularly cold-hardy for outdoors:  Brune d’Hiver, Buckley, Ezrilla, Green Forest, Hampton, Lollo Rossa, Merlot, North Pole, Red Tinged Winter, Revolution, Rouge d’Hiver, Tango, Winter Marvel.

Cold-tolerant outdoor early spring lettuces: Buckley, Crawford, Green Forest, Hampton, Merlot, New Red Fire, Revolution, Simpson Elite, Susan’s Red Bibb and Swordleaf.

Early spring lettuce Ezrilla. This variety also does well in the winter with some protection.

Winter Gardening Challenge

Digging compost into our coldframes for a winter spinach crop.
Photo Wren Vile

Winter Gardening Challenge

The Seedtime annual free Winter Gardening Challenge is just around the corner!
Dates: Sunday July 19-Wednesday July 22 2026

Time: 7:00 PM CDT every evening (with additional sessions at 10am (paid), 12pm and 3pm (free). It kicks off Sunday 7/19 at 7pm Central (8pm Eastern, 6pm Mountain, 5pm Pacific).

If you’re out in the garden right now, sweating through the heat, and you’d love to still be picking fresh food out of your yard once the frost hits, take a look at this.

A free, 4-day, live online Winter Gardening Challenge, hosted by Edwin and Paul Dysinger, the father and son team behind Seedtime, on how to keep a continual harvest of fresh food through the winter. With optional additional paid morning sessions.

Over-wintered Acadia spinach emerging undamaged from under the ice and snow. Ken Bezilla

Over the four days, Paul and Edwin (with co-host Luke Hammond and an awesome line up of guest speakers) will walk you through how to keep fresh food coming out of your garden all the way through winter. Yes, even when there’s snow on the ground, with the right cold-hardy crops and protection to hold off the cold.

And because it’s live, you can ask your real questions and build your winter garden plan right alongside them, so you walk away with an actual plan you can put in the ground, not just a pile of notes.

This year The Winter Gardening Challenge has three of the most respected fall and winter growers around joining them to teach, live:

Melissa K. Norris, the voice behind the Pioneering Today podcast and a fifth-generation homesteader who teaches people to grow, preserve, and cook their own food, will present Your Climate-Based Plan, choosing crops for your location and season, how to choose the right winter growing strategy based on climate + goals + tools available (none, row covers only, tunnels/hoophouse) on Monday at noon Central (1pm Eastern, 11 am Mountain, 10 am Pacific).

Pam Dawling, who wrote the book Sustainable Market Farming and grew food year-round managing a 3.5 acre garden for 25 years. I’m presenting Habits of a Winter Gardener (Temperature thresholds, frost strategies, crop-specific protection) on Tuesday at noon Central (1pm Eastern, 11 am Mountain, 10 am Pacific).

Nicole Burke, founder of Gardenary, who has helped so many people start a kitchen garden that actually feeds their family, is presenting Timing and Crop Selection (Fall & Shoulder Season success) on Wednesday at noon Central (1pm Eastern, 11 am Mountain, 10 am Pacific).

Every one of them is showing up live to help you grow through the winter. You get to be in the room, ask your questions, and learn from people who have actually been doing this year after year.

It’s completely free to join.

Save my spot
Takes about 10 seconds.

Overwintered Acadia spinach, weeds, March 16, Pam Dawling

Grow your best cool season garden ever.
Act fast because this event is coming up right around the corner!
On registration, users have the option to purchase the replays and VIP experience for $19 plus some optional bump and upsell offers.

Unusual Crop for July: Squash blossoms and other edible flowers

 

Zucchini flower beignets. https://www.sbs.com.au/food/recipe/fried-zucchini-flowers-beignets-de-fleurs-de-courgette/8iuji2klg 

In May I wrote about Peanuts

In June I wrote about Bug-Resistant Summer Squash Substitutes

This month, I’m writing about edible flowers, starting with squash blossom beignets.

Which Squash Varieties to Grow for Blossoms

Any summer squash, zucchini or winter squash blossoms can be used for beignets, which are a kind of fritter. Usually the male flowers are used, as harvesting female flowers would eliminate their chance of producing squash. Squash blossoms only live for a day, so you can’t have both blossom and fruit from the same flower.

If you are pulling up or tilling under a row of squash because you have too many, there is no reason not to cook the female flowers as well as the males. Female flowers have tiny squash developing immediately behind the flower. Male flowers have longer thin stems. In the first photo of Gentry yellow squash below, the flower is a male. The immature squash have thicker stems. The second photo shows a female flower with a tiny squash developing behind it. the flower is still fresh, showing you the developing squash will be quite obvious, even at a very young stage.

Gentry yellow squash with a (thin-stemmed) male flower prominent, and several small squashes.
Photo Pam Dawling
Golden Glory zucchini. Open, disease-resistant plants. A female flower with a tiny squash behind it is in the center of the photo. See the striped cucumber beetle poking its head out of the flower? Photo Pam Dawling

If you want to grow plants mainly for the blossoms, choose a vining zucchini, as these produce the most and the biggest flowers. Costata Romanesca is a good large bush one that also produces tasty zucchini.

Costata Romanesco zucchini. Fedco Seeds photo.

Butter Blossom was a zucchini developed specifically for blossoms, but seems no longer available. The web directs me to Butterbush, which is a compact bush butternut, slow developing and not sounding promising.

Johnny’s Selected Seeds has a short video on this topic:

Harvesting Squash Flowers

One trick is to be ready to harvest blossoms early in the season when the plants produce an initial flush of male flowers. Don’t kill your golden goose, though, by removing all the male flowers and leaving no chance of pollination. You can leave some male flowers on the plants once there are female flowers, and/or use a paintbrush to transfer pollen from male flowers to the stigmas of female flowers as soon as they open in the morning. Don’t dally, as once the female flowers close, you’ve missed your chance.

Harvest the blossoms early in the morning, while they are still crisp. You can use either closed or open flowers for beignets. The advantage of open flowers is their size compared to unopened flowers. Their disadvantage is that they might contain insects, so be sure to check and shake our any you find.

Snip through the stems with pruners and gently settle the flowers in a very clean tote. Some cooks remove the stems and sepals before dipping in batter, but you can use the stem as a handle and remove it later. Or let the diners deal with it. Don’t wash the flowers, as this can make the batter soggy. Simply discard any grubby flowers.

Cooking Beignets

Fried Zucchini flower beignets. https://yourguardianchef.com/fried-zucchini-flowers/

I’m no cook, but basically you make a batter, as simple or fancy as you like, using two cups of plain flour for around 15 open flowers. Batters with and without eggs work equally well, I am told. The batter should be a little thinner than pancake batter.

Heat an inch or more of oil in a pan, dip the blossoms in the batter until well-coated, then fry in hot oil for a few minutes, turning as needed. Drain, salt, and serve hot. Cooked beignets can be frozen for reheating later, although to me that sounds a poor choice compared to eating them immediately!

Some recipes suggest you use either a tempura type batter, or chili relleno style fluffy batter. Some recipes stuff the flowers before frying with soft cheese, garlic, herbs, Parmesan.

These are a fun, delicate treat, not a belly-filling farmer dinner, and we all need some fun in our lives!

Tiny squash can also be used for beignets, and squash vine tips can be cooked the same way or stir-fried without batter.

Squash vine shoots for cooking. Photo Irena Hollowell

Other Edible Flowers

There are plenty of other edible flowers, mostly used in salads or as garnishes, without cooking them. Johnny’s has a good selection and also a 4-page printable guide. Both links are full of inspiring photos. They recommend nasturtiums, calendula, bachelor’s buttons for salads; marigolds, dianthus and violets for garnishes; mint, basil and borage flowers to flavor summer drinks; beebalm, anise hyssop and marigolds to add zip to desserts. Arugula, fava bean, pea, mustard and strawberry flowers also feature in their Edible Flowers Guide, along with more herb flowers, snapdragons, stocks, sunflowers (I just learned the whole sunflower plant is edible, which conjures up quite an image!).

Nasturtiums planted in with squash to deter pests. 
Photo Pam Dawling

Garden Betty,  whose writing I am quite a fan of, has a huge and beautiful post on edible flowers, including many not yet mentioned here: alyssum, amaranths, begonia, catmint, celosias, chamomile, clovers, cosmos, dahlias, dandelions, daylilies, dianthus, echinacea, evening primrose, fuchsia, phlox, gardenia, gladiolus, hibiscus, hollyhock, honeysuckle, hostas, impatiens, jasmine, lilac, nigella, okra, orchids, petunias, plumeria, primroses, roses, stocks, tulips, yarrow, and zinnias.

Yarrow flowering in our hoophouse, to attract beneficial insects. The flowers are edible.
Photo Pam Dawling

I recommend this site and its clear photos, for anyone venturing into new flower-eating territory. Garden Betty (Linda Ly) describes the flavor profile of each plant. Her list is compiled from all the flowers she’s personally tasted over the years.

She cautions about harvesting and eating flowers you don’t know, or that might be contaminated with pesticides. Start with small quantities if you are uncertain of the ID, especially if you tend towards allergies and sensitivities. She gives the Latin botanical names, so you can be sure of any you are growing from seed.

This site also gives links to books, such as her The No-Waste Vegetable Cookbook, her How to Eat the Parts of Plants You Didn’t Know You Could Eat and 28 Edible Weeds and Invasive Plants That Are Actually Delicious, for sale as a digital downloads.

The No-Waste Vegetable Cookbook by Linda Ly

A Few More Good Resources

University of Minnesota Extension Edible Flowers

Food Garden Life

10 Poisonous Flowers You Should Never Eat

See Thompson and Morgan’s Edible Flowers Guide

A 200-year-old Norwegian Farm; and an ancient fertilizer returns to use.

A 200 Year Old Norwegian Farm

Here’s a lovely video I found in the newsletter from Lynbreck Croft, in the highlands of Scotland.

Sandra says:

“This month’s recommendation points to a short film rather than a book. It portrays the life of Helene, a farmer who cares for her land on the west coast of Norway.

To me this story represents all that is good in this world. A deep sense of connection and rootedness to the land, a love for traditional skills and creation of things that are both useful and beautiful, an appreciation for natural materials, the respectful interaction with animals, the care of one’s belongings ensuring their longevity, supporting people in finding their place in the natural environment…

Among many others, one of the messages that really stuck was that the effort of each and one of us to make a difference in this world matters. It has value, irrespective of how seemingly small it might seem in the moment and that is such an encouraging thought to carry along through life.”

24 Hours on a 200 Year Old Norwegian Farm (a video everyone should watch)

https://www.youtube.com/watch?v=n6QkaMpVHcg

This is Helene Olli. I just want to add, that the people Hunter call[s] “farm hands” is [are] WWOOFers and other volunteers. I have been a host for WWOOF Norway since 2015. I have had so much help from fantastic people from around the world th[ese] summers, also some winters. I really, really want to give them credit for helping me [with] building the farm, and also running it. My policy is this: if you stay in Gripen, helping with the farm, it gets a little bit yours. I have a lot of returning volunteers, and I feel I have a much bigger family because of this. I am so happy and thankful that they want to stay and contribute. I wish that could have been more visible in the video, but I am saying it now. I am so blessed, having so much good people around!

LynBreck COURSES – Limited availability left for 2026

Lynbreck BOOK. Our Wild Farming Life: Adventures on a Scottish Highland Croft. I have reviewed their book Our Wild Farming Life.

Or you can sign up to be on the mailing list for their newsletter.

———————————————————-

Aurin Fertilizer: an ancient fertilizer returns to use

On a completely different topic, linked to the one above by the desire and practice of living lightly on the earth, here is information about Aurin, a fertilizer from VunaNexus, that is approved for use in France and Switzerland. Not available in the US, so you’ll have to make your own. I wrote about urine fertilizer Here.

Bottle of Aurin Fertilizer

The VunaNexus company say they are recovering minerals, similarly to what is commonly done to recover minerals from used electronics. They supply urine-diverting toilets which send the urine (without diluting it with water) into a small treatment plant in the basement of the building. The treatment plant first removes pollutants such as antibiotics, hormones, and drug residues, then concentrates the nutrients such as nitrogen and phosphorus while pasteurizing the liquid at 90C (194F) to kill potential viruses and other pathogens. Pure water is distilled out of the liquid and returned to the flushing system. This leaves Aurin, the liquid fertilizer, sold in 0.5 L (1 quart) recyclable PET bottles, as well as 5 L (1.3 US gallons), and 10L (2.6 US gallons) jerricans.

Label of Aurin fertilizer

Their urine-diverting toilets are used by the European Space Agency in Paris and the fertilizer is being tested by city authorities in Paris, Lausanne and Zurich. Any lingering prejudice that this is just a hippy idea is fading fast in these days of fertilizer supply chain disruptions in the Strait of Hormuz. The UN says 45 million people are at risk of acute hunger because the conflicts in the Middle East have increased fertilizer prices. We don’t need petroleum-based fertilizers as long as we have urine!

The chief executive of VunaNexus says that if we recycle all the human urine in Europe, we could provide 30% of the nitrogen needs of their farms, provide a more sustainable option to water treatment systems, and reduce the environmental impact of petroleum fertilizers.

Aurin in large-scale agricultural use. Photo VunaNexus

The original idea came from a research project over 10 years ago in South Africa. I read about this company in the Guardian of 12 June 2026 in an article by Chloe Farand

Here’s a late addition from Harvest to Table by Stephen Albert.

He has just reorganized his writings on the topic of Surviving the Summer Heat—Your Complete Guide to Gardening Through Heat Waves

in a special edition of his Substack

This post has lots of helpful tips on heat stress, watering, shade, mulch, pollination, and helping plants recover from heatwaves.

Success with Growing Carrots!

Danvers Half-Long carrot.
Photo Southern Exposure Seed Exchange

It’s carrot planting time for many of us from spring to late summer, and many growers are searching my site for information. Here are quick links to all of my many carrot posts over the years. Inevitably there is some overlap.

After these links there are seasonal details on planting carrots.

  • Carrot Seed Viability: you may be wondering if you can still use the seeds leftover from last year. Carrot seeds are generally good for 3 or 4 years if you have stored them carefully. Click the link above to read Factors influencing seed viability and Seed germination testing
  • See my slideshow on Succession Planting. We sow carrots from mid-February to August. Here’s Video of me presenting Succession Planting for Continuous Vegetable Harvests ten years ago at New Country Organics (I’ve updated the presentation since then);
  • Sowing carrots: Surprisingly to me, I have not written much about sowing carrots in spring. From Root Crops in February: Carrots do very poorly with competition from weeds or too many other carrots. You can make use of the Stale Seedbed Technique, preparing the bed ahead of time, and flaming or hoeing one or more flushes of weeds as they germinate.
A young carrot bed in April, ready to hoe and thin.
Photo Pam Dawling

Carrots are small seeds, needing a fine tilth (small soil particle size and good texture – not likely to crust or blow away).  Good information on crop spacing for maximum yields, or biggest vegetables is in an out-of-print book, The Complete Know and Grow Vegetables by JKA Bleasdale, PJ Salter, and others. Buy it used.

For maximum total yield of carrots, they recommend 1.5” x 6” (4 x 15cm). You get medium-sized carrots. For early carrots go with 4 x 6” (10 x 15cm) to minimize competition and get rapid growth. If you want to have rows more than 6” (15cm) apart, calculate the area of these optimum spacings, then divide by your chosen row space. For example, if your rows are 12” (30cm) apart, the carrots can be as close as 0.75” (2cm) if total yield is more important than individual size, or 2” (5cm) for fast early carrots. We do five rows in a 4’ (1.2m) bed, so the rows are about 10” (25cm) apart, with the outer rows 4” (10cm) from the bed edge.

From Root Crops in March:

Spring Carrot Start-up Plan

  • One of many wheelbarrows full of compost we spread every year.
    Photo Wren Vile

    We aim to spread compost 4-6 weeks before planting, rototill 2-4 weeks before planting, and prep the bed a week or two before. This is more time than we allow later in the year, but in early spring it’s good to seize the opportunities that arise and not take the weather for granted.

  • This means in January we compost and till beds for our first two beds of carrots, to be sown February 14 and February 28.
  • In the first half of February we till and spread compost for more carrots (planting dates March 9 to 15).
  • In the second half of February, we compost the third carrot bed and till the ones we already composted.
  • Once we get to March, day length has improved and temperatures are starting to climb. There is a noticeable increase in the rate of germination and growth (unlike our February sowings, which are rooted in faith and optimism!).
  • In early March we till the third carrot bed.
  • All being well with the weather, we sow carrots #3 in mid-March
  • In late March, we sow carrots #4
Carrot beds in June. Bridget Aleshire

There’s also a full chapter on carrots with all my information in my book Sustainable Market Farming, 2nd edition. It includes info on varieties, and which types are better for which soils, pests and diseases, crop rotations, cover crops before and after carrots, and more.

Preparing for Carrot Sowing

    • Planning for a continuous supply; see my slideshow on Succession Planting. Carrots have a much longer window for harvesting than most carefully planned successions, so you can be a lot looser in your planting dates. Mainly, just grow enough! After the spring start-up plan, we sow carrots once a month in April and May. If we need to, we sow once a month in June and July, although summer-grown carrots do not taste as sweet as those grown in cooler weather. We finish with a big sowing at the end of July or early August, 10–12 weeks before the usual first frost, to be harvested in November and stored for winter eating.
    • Decide how many to plant. Yield: 100 lb/100′ (150 kg/100 m), 30,000 lb/acre (34,000 kg/ha)
    • Calculate the amount of seed required; Carrot seeds are 175,000–600,000 (avg. 288,000)/lb, 18,000 seeds/oz, 625 seeds/g. 3,000 seeds (0.2 oz, 6 g)/100′ (30 m), 1 seed/cm. 625 cm/g, 600’/oz, 9,600’/lb, 2.5 lb/acre (at 30 seeds/ft in rows 24″ (60cm) apart). 720,000 seeds/acre.

Success with Planting Carrots

    • Before you plant, understand soil temperature requirements: Use a soil thermometer! Flag its location so you don’t lose track of it! Measure at 4″ (10 cm) deep at 9am. Carrot emergence takes3 days at 50°F (10°C), 10.1 days at 59°F (15°C), 6.9 days at 68°F (20°C), 6.2days at 77°F (25°C), 6 days at 86°F (30°C)and 8.6 days at 95°F (35°C).

      Soil thermometer. Worth its weight in gold.
    • Old books warn against using manure before sowing carrots as it will make them fork. This refers to uncomposted manure, not compost. Compost will increase yields and even reduce the culls with some varieties (research by Dan Brainard and Corey Noyes, at Michigan State University). Compost not only increases the organic matter in the soil but also suppresses some diseases and nematodes (which can cause forked carrots)
    • Seed spacing and depth: for carrots, aim to sow 30 seeds/ft (1/cm), only 0.25″–0.5″ (0.6–1.2 cm) deep. Close the furrows and tamp down the rows with the back of a hoe or rake. The goal is to get good contact between the seed and the soil. Keep the soil surface damp until the seedlings start to emerge.
    • We sow a few Indicator Beets at the beginning of the bed. Beets germinate
      We sow “indicator beets” with our carrots so that we know when to flame-weed them
      Photo Kathryn Simmons

      one day sooner than carrots at almost any temperature. When we see the red loops of the beet stems emerging, we know it’s the day to flame weed the carrots. (From Workhorse Crops for March)

    • Carrots do very poorly with competition, so try to start early carrots in a bed that had only light weeds the year before. Later sowings can make use of the stale seedbed technique, where the bed is prepared ahead of time and one or more flushes of weeds are germinated and flamed or hoed off.

      Carrot row thinned to 1 inch. Kathryn Simmons

Growing Great Carrots: Thinning and Weeding

    • Remember to thin carrots as soon as you can see them well enough to do so. We usually hoe between the rows first, then crawl along thinning and weeding. It does take time! But you won’t get good carrots without thinning, unless you either have a precision-seeder that drops one seed per inch, or pelleted seed which you can sow at one per inch.
    • Precision seeders like the Jang are expensive, but worthwhile if you need to use it every week. Pelleted seed costs more than raw seed, and its big advantage is traded off for two other disadvantages: The soil has to be kept well-watered until germination or else the clay coating will imprison the seed forever, and the seed does not store for long – don’t keep any over for next year.
    • It pays to sow in parallel rows an even distance apart. This makes for fast and effective hoeing with fewer mistakes.

      Danvers 126 carrots.
      Credit Southern Exposure Seed Exchange

Harvesting carrots

Carrot trimming and sorting. Wren Vile

Podcast with Seedtime, on Growing Food in an Intentional Community

Here’s a podcast I did with Seedtime.us

My name is spelled wrong on the YouTube page. It’s Dawling, not Dowling.

The title of the podcast refers to our decision some years ago, after 15 years of extensive trials, to stop growing bulb onions. Luke Hammond, the interviewer, was surprised we have chosen to forego such a basic crop. Most of the podcast is not about onions! But here I will give some background to that decision.

Onion variety trial bed in late April.
Photo Kathryn Simmons

Onion Varieties

Onions are an exacting crop. Knowing how to get the best from your seeds will greatly improve your chances of success. It’s important to grow varieties that are suitable for the latitude of your farm.  The further north you are, the longer the number of daylight hours you have in summer. I garden on the 38th parallel, the natural home of neither the Short day (Sweet Vidalia type) nor the Long day onion (hard, strong-flavored storing varieties). The names refer to the relative daylight length needed before the plant will start to make a bulb. The dividing line between short day (south of 35º) and long day (north of 38º) varieties is around 35-36-37º latitude. This reality, plus my own confusion, led us to study and experiment to find ways to work with the needs of this crop, to improve our harvest.

Onion Growth Stages

Onions are cool season plants.  They have 3 distinct phases of growth and the switch from one to the next is triggered by environmental factors.  It does not work to plant onions at a random date in the year without taking account of these environmental factors. Onions transition from the vegetative (leafy) to the bulbing stage at a precise daylength for that variety.

To grow large onions it is important to produce large healthy plants before the vegetative stage gives way to the bulbing stage.  Each onion leaf represents one ring of the future onion bulb.  The larger the leaf, the larger the ring becomes.  If plants are small when bulbing starts, only small bulbs are possible.  Cool, but not cold, weather encourages heavy leaf growth.  Onion seedlings are slow growing – in spring they can take 10 weeks to reach a size suitable for transplanting.

Here at 38ºN, our longest day (summer solstice) has 14 hours and 46 minutes of daylight. We have 14 hours of daylight on May 6th.  A few varieties of Long Day onions can be grown here, but those requiring 15 or 16 hours of daylight will never form bulbs at this latitude, unfortunately.

Onion Types

Short Day onions start to bulb at 10-12 hours of daylight, provided temperatures are warm enough.  In the south, below 35ºN, they are sown in September or October, grow through the winter, and are harvested in May-June. Onions can survive 20ºF (-6.7ºC), but not worse. We have tried over-wintering onions outdoors, but even with rowcover, our losses were too high. Here we reach 10 hours of daylight on January 21; 11 hours on February 20; and 12 hours, naturally enough, at the spring equinox. Bulbing initiation gets delayed  beyond the daylight trigger, until temperatures are higher than 60ºF-70ºF (15.5ºC-21ºC), (which is early April here). If we grow Short Day varieties here, they only have a brief time in spring  to grow a decent sized plant before bulbing starts. Therefore it’s a waste of time to sow Short Day onions here in spring.

Hot, wet weather is the worst for onion growing and harvesting, so it is best not to let the onions sit around in wet soil during very hot days. Harvest them, get them under shade and a roof to dry down. Trimming should begin about two weeks after you started hanging the onions.

Bulb onions curing on a rack.
Photo Wren Vile

After a rack has been hanging for two weeks, test them by feeling maybe a dozen necks to see if they are ready for trimming. This involves pinching the necks gently just next to the bulb, and then rubbing/rolling your fingers together. They are ready for trimming if the majority of the necks feel dry and strawy.

Why We Didn’t Succeed With Onions

We really wanted to grow bulb onions for year-round use, therefore we needed some storing onions. We can grow “Eat Right Away” onions, but only for a short window of the year. Local growers succeed with onions by growing varieties like Ailsa Craig to sell freshly harvested. But a ton of onions for one week didn’t answer our need! The storing long day varieties mostly grow north of 38º, not here. We found a few with small success (short term storage).

Our second problem was our curing conditions. Our barn is hot and sometimes humid. We needed fast drying so they didn’t rot. The onions we could grow were not as huge as the big round onions we could buy (not organic) at the wholesale market. Our cooks preferred convenience over Organic. Remember, cooking for a hundred people is not a walk in the park!

So, eventually we gave up on bulb onions. We grew yellow potato onions for quite a few years. Those aren’t big either, but the small ones do store very well. Nowadays we grow lots of garlic and lots of scallions.

Yellow Potato Onions.
Photo Southern Exposure Seed Exchange

 

Unusual Crop for June: Plant Bug-Resistant Summer Squash Substitutes

Bug-Resistant Summer Squash Substitutes 

Tromboncino Squash. Southern Exposure Seed Exchange

Most summer squash and zucchini are in the species Cucurbita pepo. They are easy to grow —the main challenges are pests, diseases, and moderating the quantities available. These crops can crank out high yields of a vegetable almost everyone likes.

Where insects are a problem for summer squash, vigorous plants of other squash and gourd species can bear all season in those areas. Growers with bad pest problems can try:

  • Tromboncino squash (60d OP), a C moschata squash; Light green fruits grow long, curving to a bell at one end. Vigorous vining plants that can be grown on a trellis. Harvest at 8”-10” (20-25 cm) long when the flavor is fine and sweet. Southern Exposure Seed Exchange. On the coast of France and Italy, Tromboncino d’Albenga and Trompette de Nice were traditionally grown as summer squash and a few fruits left to ripen for winter storage.
  • Zucchino Rampicante (60-70d OP) C moschata; Italian heirloom, vigorous vining squash; long slender 15” (38cm) fruit with a bulb at the bottom. One of the best eating summer squash: very tender, mild tasting. The long neck makes great slices with no seeds in them! Insect and disease resistant. Baker Creek.

    Rampicante squash. Baker Creek
  • Tromboncino and Rampicante are closely related, if not the same.
  • Long de Nice (C moschata); Fruit range in size between 10-20 lbs (4.5-9 kg) each with a long neck and fine-grained flesh with few seeds. Vines spread at last 15ft (4.5m), consider trellising. One or two full-grown squash per vine, but you’ll get more if you harvest them immature. Generally not as long as Rampicante or tromboncino. Baker CreekLong de Nice squash. Baker Creek
  • Luffa (Luffa acutangula and aegyptiaca vegetable sponge, 65d OP, zones 7-13), Very long vines, consider trellising. Tastes similar to summer squash when harvested at 4” (10cm) for eating raw, pickled, cooked with other vegetables. The mature fruits are harvested when the skins dry brown, to use as vegetable bath sponges or pot scrubbers, with an incidental seed harvest at the same time.

    Maturing Luffa. Seed from Survival Garden Seeds
  • Cucuzza (Lagenaria siceraria, snake or serpent gourd, 60-75d OP grows in zones 2a-11b.) Cucuzza edible gourds have more resistance to squash bugs. Just be sure to harvest them relatively small (while skins can be pierced by a fingernail, 12” (30cm) max) for good flavor. These are very vigorous, sprawling plants, which, happily, are also prolific. One option is to plant a row of regular zucchini alternating with these bigger plants —when the zucchini succumb to disease, the sprawlers will take over. Vines can reach 25’ (7.6m)

    Cucuzza Seeds from Italy.
    Growitalian.com
  • Lunga Da Pergola (Lagenaria siceraria, 60d to 6” (15 cm) fruit). Edible gourd, vigorous vines. At its best small, about 6” (15cm) long, when fruits will be slightly sweet and tender. Fruit can grow up to 5’ (1.5 m) long. A very productive strain with white mottling on the gourd and leaves.

    Serpent Gourd Lunga di Pergola. N E Seeds

Some zucchini varieties are especially attractive to cucumber beetles and may be grown as a trap crop: Cocozelle summer squash, Seneca, and Dark Green zucchini. When beetles accumulate in the trap crop, flame it or till it in.

Crop Requirements for Squash and Gourds

Summer squash thrives on high levels of organic matter. Although only a light to moderate feeder for nitrogen and phosphorus, it requires quite high levels of potassium. Foliar seaweed spray can be used to make up for nutrient deficiencies. This crop does best with plentiful, but not excessive, moisture. That said, be careful not to overwater the seeds before they germinate, or they will rot.

This frost-tender warm-weather crop germinates at 60°F (15.5°C) minimum and does best at 85°F (30°C). Germination takes 5–10 days. During growth the ideal temperatures are 75°F–85°F (24°C–30°C) in the day and 65°F (18°C) at night.

Sowing Squash and Gourds

Seed can remain viable for up to 5 years, if stored in a cool, dark, dry place. Seeds should be sown 0.5″–1″ (1–2.5 cm) deep, 6″–12″ (15–30 cm) apart, in widely spaced rows if you are not trellising. Sow deeper in hot weather, when it helps to turn on the drip irrigation, and sow each seed right by an emitter. Water at sowing, then not again until seedlings emerge. For a slightly earlier harvest, you can pre-sprout the seed.

Covering the row with netting will keep the pests away. If possible, use hoops or a rope above the row, pulled taut between stakes, to hold the netting above the leaves, as cucurbits are susceptible to abrasion damage. Remove the netting as soon as you see female flowers, to allow for pollination.

Transplanting Squash and Gourds

When transplanting squash, take care to disturb the roots as little as possible. If you sow 2 seeds in each cell, be sure to pinch off the smaller one as soon as possible to remove the competition.

As soon as the plants have one or two true leaves, at about 3–4 weeks of age, transplant in a mild spell, burying the entire stem below soil level, up to the seed leaves (carefully!) to protect it from damage. Cucurbits started indoors grow long spindly stems, which are quite fragile. Make the hole deep enough, slip the plant out of the container, perhaps on the blade of a knife, pop it into the hole, and close up firmly.

Plant 2’–3′ (60–90 cm) or more apart in the row. Transplanting allows a crop to be established earlier than would be possible with direct sowing in spring. Alternatively, a crop can be gained from a summer window in the planting schedule for a bed, after an early spring crop. Transplants do not grow as sturdy a root system as direct sown squash do, so I would not recommend transplanting if direct sowing is possible.

Pests of Squash

Squash bugs are probably the most common pest. The adults are long gray insects that emerge from overwintering in wooded areas once temperatures reach about 70°F (21°C). They are more attracted to pepo squash than they are to moschatas. Plants attacked by squash bugs look baked to a crisp, with curled bronzed leaves. Squash bugs can do a lot of direct damage to leaves, and they also vector yellow vine disease. They feed on young seedlings for preference and lay groups of spaced bronze eggs on the undersides of leaves. The eggs hatch in 10 days, and the nymphs suck sap from the plants. There are many generations each year, and numbers quickly build. Drop handpicked adults into soapy water rather than crushing them as the smell of the crushed bugs attracts more. It is also possible, but not easy, to crush the hard-shelled eggs. An alternative is to tear off egg-covered leaf pieces and drown the eggs in soapy water. Squash bugs can be trapped overnight under boards on the soil near the plants —in the morning, lift the boards and collect the bugs.

For more info on squash bugs, see the ATTRA publication, Squash Bug and Squash Vine Borer: Organic Controls, that includes pest lifecycles, systems-based management practices, mechanical and physical practices, and biological and botanical controls. Buckwheat can be interplanted to attract tachinid flies that parasitize squash bugs.

Striped cucumber beetles are our worst pests some years, even compared to squash bugs. In the hoophouse, we handpick the adults inside squash flowers in the mornings while they are still sluggish. Long pointed tweezers are our tool of choice. Our hope is that, by battling this first generation, we will reduce numbers for the rest of the season. To attract beneficial insects that are predators or parasites of the cucumber beetle, grow buckwheat, cilantro, dill, or winter peas near the squash plants, timed so that they flower when the rowcover or netting is removed from the squash plants. Another method of reducing pest attacks, especially useful after flowering, is Surround kaolin clay spray. It does need renewing after rain or overhead irrigation. If all else fails and action is imperative, Spinosad will kill them (and some other insects too).

The adult squash vine borer is a fairly large orange-and-black fuzzy moth with glassy black wings. It is active in May and early June, and there may be a second generation in late July/early August. The small flat brown eggs are laid singly at the base of the stem. The larvae hatch after 1 week, and are white with a brown head. They spend 4–6 weeks in the stem, eating upwards and growing to 1″ (2.5 cm) in size. Then they dig into the soil and pupate for the winter.

Plant symptoms include wilting of the whole plant and stem holes surrounded by frass (caterpillar poop). To save the plant, act at the first sign of trouble and pick out the grub, then pile soil over the injury to help the plant recover. Injecting Bt (Bacillus thuringiensis) into the stem is another solution. For prevention, rotate crops and use netting or rowcover over plants until flowering. Another technique to try is pinching out the growing tips of the vine when it is 1’–2′ (30–60 cm) long, which causes the plant to branch and increases the odds that some part of it will survive.

Diseases of Squash and Gourds

I haven’t yet done a Plant Diseases of the Month Series, so I’ll include info here.

  • As always, aim to avoid diseases by ensuring good air flow and appropriate water levels.
  • Powdery mildew (PM) (a white coating starting on older leaves) is a common fungal disease in hot dry weather. Drip irrigation helps reduce the spread of PM, compared to overhead irrigation.
  • Downy mildew (yellow angular spots with leaf curling and a purplish cast to the undersides of leaves) happens in cool wet weather late in the season, and plants can recover if the weather heats up.
  • Anthracnose (dark brown spots on the leaves and round sunken spots on the fruit) is a fungal disease worse in warm wet weather from mid-season onwards.
  • Angular leaf spot, Pseudomonas syringae pv. lachrymans (browning of the leaf between the veins and small round spots on the fruit) is a bacterial disease more common in cool damp weather. The symptoms can resemble those of downy mildew.
  • Black rot/gummy stem blight (Didymella bryoniae) is a fungus occurring with wet soils, in wet weather (cool or warm).
  • Mosaic viruses can be spread by aphids. Succession cropping helps evade these.
  • Bacterial wilt (Erwinia) causes sudden dramatic wilt and death of the whole plant. It is spread by cucumber beetles.

This post is adapted from a chapter in my second edition of Sustainable Market Farming, with some additional information on squash varieties.

Front cover of Second Edition of Sustainable Market Farming book
The second edition of Sustainable Market Farming, release April 15, 2025