At the Organic Growers School Spring Conference I gave my presentation The Seed Garden, about combining growing some seed crops alongside lots of vegetable crops – a way for vegetable growers to diversify and grow seed of a few special crops either for themselves or to sell for some extra income and to keep a chosen variety available. I included information on selecting desirable characteristics and making an improved strain of that variety.
You can watch the slideshow here, by clicking on the diagonal arrow to increase the screen size and then the right pointing triangular arrow:
I also took the opportunity to add a few more of my slideshows to my collection on SlideShare.
Meanwhile I’ve been sorting out more photos from my Cuba trip, and I want to tell you about a bean seed bank at Finca Hoyo Bonito I visited during our day traveling from Havana, west for three hours to the Viñales Valley in the province of Pinar del Rio.
The seed farm has a bank containing 250 varieties of bean seed. It’s a hobby for the retired woman growing and saving the beans. Her goal is to get a hundred pounds of each variety. She gives bean seed to any farmer who asks, with no requirement to return the investment. (this is different from some seed banks, which require growers to repay the “loan”)
Here is a short video about Finca Hoyo Bonito. It’s in Spanish, naturally!
At the Organic Association of Kentucky Conference, I gave a a presentation on Winter High Tunnel and Outdoor Vegetable Production. You can see it here. Click on the diagonal arrow icon to see it full screen, then click on the right pointing triangular arrow
Winter-Kill Temperatures of Cold-Hardy Vegetables 2020
I keep records of how well our crops do in the colder season, both outdoors and in our double-layer hoophouse. I note each increasingly cold minimum temperature and when the various crops die of cold, to fine-tune our planning for next year. We are in zone 7a, with an average annual minimum temperature of 0-5°F (-18°C to -15°C).
The winter 2019-2020 has been mild, with our lowest temperature being a single night at 12°F (-11°C). The Koji became completely unmarketable but did not completely die. Yukina Savoy is indeed hardier, being OK down to 10°F (-12°C). We had one night at 13°F (-10°C) and two each at 17°F (-8°C), 18°F (-8°C also) and 19°F (-7°C).
This winter I noted the death of rhubarb stems and leaves at 25°F (-4°C), rather than 22°F (-6°C), as I noted a year or two ago.
In early January 2018, we had some extremely cold temperatures of -8°F and -9°F (-22°C and -23°C). The winter of 2018-2019 was not as brutal. Our lowest temperatures were 6°F (-14°C) in late January, 8°F (-13°C) in December 2018 and a couple of 11°F (-12°C). I found that senposai is more cold-tolerant than I had thought. Averaging our winter low over those three winters gives 3.2°F (-16°C), completely within the zone 7a range.
My other results from other years still hold up.
I also learned that there is more damage when the weather switches suddenly from warm to cold. And that the weatherman in Raleigh, NC says it needs 3 hours at the critical temperature to do damage.
Radicchio seeds from Seeds from Italy
Notes on Chicories and Endives
We gave up growing chicories and endives because we really didn’t like the bitterness. I decided to do some more online research to make sure I wasn’t spreading untruths. Chicories and endives fall into two groups, but they are confusing because the common names sometimes suggest the opposite group than they are botanically. Here’s the best info I have. If you know differently, please leave a comment.
Cichorium intybus, commonly called chicories, are mostly heading crops. The group includes radicchio, both Treviso and Chioggia (hardy to about 20°F (-7°C). Belgian Witloof endive (the kind for forcing chicons) is also a chicory. It dies at 25°F (-4°C). Sugarloaf chicory is the least hardy chicory, and dies at 27°F (-3°C).
Cichorium endivia, commonly called endives, are mostly loose-leaf crops, less cold-hardy than intybus types (chicories). This group includes Frisée types and escaroles, which are also known as Batavian endives. They generally survive down to 22°F (-6°C), although Perfect and President endives can survive down to 10°F (-12°C) – can anyone confirm or deny this?
Using the List
Unless otherwise stated, these are killing temperatures of crops outdoors without any rowcover. All greens do a lot better with protection against cold drying winds. Note that repeated cold temperatures can kill 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. Your own experience with your soils, microclimates and rain levels may lead you to use different temperatures in your crop planning.
Our double-plastic hoophouse keeps night time temperatures about 8F (4.5C) degrees warmer than outdoors, sometimes 10F (5.5C) degrees warmer. Plus, plants tolerate lower temperatures inside a hoophouse. The soil stays warmer; the plants recover in the warmer daytime conditions (it seems to be the night+day average temperature that counts);
In the hoophouse (8F (4.5C) degrees warmer than outside) plants without extra rowcover can survive 14F (7.7C) degrees colder than they could survive outside; with thick rowcover (1.25oz Typar/Xavan) at least 21F (11.6C) degrees colder than outside.
For example, salad greens in our hoophouse can survive nights with outdoor lows of 14°F (-10°C). Russian kales, lettuce, mizuna, senposai, spinach, tatsoi, turnips, 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.
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 Rumpled Wave, Marvel of Four Seasons, Merlot, New Red Fire, North Pole bibb, Oscarde, Outredgeous, Pirat, Red Cross bibb, Red Sails, Red Salad Bowl, Red Tinged Winter,Revolution, Rouge d’Hiver, Salad Bowl, Sylvesta bibb, Tango, Winter Marvel, Winter Wonderland.
Outdoor killing temperatures of crops (unprotected unless stated)
35°F (2°C): Basil.
32°F (0°C): Bush beans, some cauliflower curds, corn, cowpeas, cucumbers, eggplant, limas, melons, okra, some pak choy, peanuts, peppers, potato vines, squash vines, sweet potato vines, tomatoes.
27°F (-3°C): Many cabbage varieties, Sugarloaf chicory (takes only light frosts).
25°F (-4°C): Some cabbage, chervil, Belgian Witloof chicory roots for chicons, and hearts, Chinese Napa cabbage (Blues), dill (Fernleaf), some fava beans (Windsor), annual fennel, some mustards (Red Giant, Southern Curled) and Asian greens (Maruba Santoh, mizuna, most pak choy, Tokyo Bekana), onion scallions (some are much more hardy), radicchio, rhubarb stems and leaves.
22°F (-6°C): Some arugula (some varieties are hardier), Bright Lights chard, endive (Escarole may be a little more frost-hardy than Frisée), 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)), Brussels sprouts, some cabbages (the insides may still be good even if the outer leaves are damaged), some cauliflower varieties, celeriac, celtuce (stem lettuce), some head lettuce, some mustards/Asian greens (Tendergreen, 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).
Large oat plants will get serious cold damage. Oats seedlings die at 17°F (-8°C)
Canadian (spring) field peas are hardy to 10-20°F (-12 to -7°C).
15°F (-9.5°C): Some beets (Albina Verduna, Lutz Winterkeeper), beet leaves, some broccoli, some cabbage (Kaitlin, Tribute), covered celery (Ventura), red chard, cilantro, fava beans (Aquadulce Claudia), Red Russian and White Russian kales, kohlrabi, some lettuce, especially medium-sized plants with 4-10 leaves (Marvel of FourSeasons, Olga, Rouge d’hiver, Tango, Winter Density), curly leaf parsley, rutabagas (American Purple Top Yellow, Laurentian), broad leaf sorrel, most covered turnips, winter cress.
12°F (-11°C): Some beets (Cylindra,), some broccoli perhaps, Brussels sprouts, some cabbage (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, some turnips (Purple Top).
10°F (-12°C): Covered beets, Purple Sprouting broccoli for spring harvest, a few cabbages (Deadon), chard (green chard is hardier than multi-colored types), some collards (Morris Heading can survive at least one night at 10F), 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 winter radish (Daikon, China Rose, Shunkyo Semi-Long survive 10°F/-12°C), Senposai leaves (the core of the plant may survive 8°F/-13°C), large leaves of savoyed spinach (more hardy than smooth-leafed varieties), Tatsoi, Yukina Savoy.
Oats cover crop of a medium size die around 10°F (-12°C). Large oat plants will die completely at 6°F (-17°C) or even milder than that.
5°F (-15°C): Garlic tops even if small, some kale (Winterbor, Westland Winter), some leeks (BulgarianGiant, Laura), some bulb onions, potato onions and other multiplier onions, smaller leaves of savoy spinach and broad leaf sorrel. Many of the Even’ Star Ice Bred greens varieties are hardy down to 6°F (-14°C), a few unprotected lettuces if small (Winter Marvel, Tango, North Pole, Green Forest).
0°F (-18°C): Chives, some collards (Blue Max, Winner), corn salad (mâche), garlic, horseradish, Jerusalem artichokes, Even’ Star Ice-Bred Smooth Leaf kale, a few leeks (Alaska, Durabel, Tadorna); some bulb onions, yellow potato onions, some onion scallions, (Evergreen Winter Hardy White, White Lisbon), parsnips (probably even colder), salad burnet, salsify (?), some spinach (Bloomsdale Savoy, 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 slightly colder
-5°F (-19°C): Leaves of overwintering varieties of cauliflower, Vates kale survives although some leaves may be too damaged to use.
-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 cabbage 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).
I mentioned before that I took part in the Organic Growers School Cuba Agroecolgy Tour in January. I’ve made some progress sorting through my photos, and this post is about Organopónico Vivero Alamar(Alamar Urban Organic Farm) on the outskirts of Havana. Alamar is one of the largest and most successful urban farms in Havana, and it is very impressive. It was founded in 1997.
During the Special Period in Time of Peace in Cuba (1991-2000), an extended period of economic hardship following the collapse of the Soviet Union combined with a US trade blockade, Cubans were thrown back on their own resources. This was described to me as “Cuba went to bed with privilege and woke up with nothing.” Food, fuel and equipment were not imported, and people began producing food wherever they could. Because there were no fertilizers or pesticides, vegetables and fruit were grown organically. In time, Cubans came to see the superiority of organic farming, and today the urban farms and small-scale food-producing farms continue to be organic (Cuban organic standards are not the same as USDA requirements). Commodity crops (tobacco, coffee, sugar) however, are not usually organically grown.
Alamar Urban Organic Farm covers 11 hectares (27 acres) in a residential dormitory suburb, surrounded by grey prefabricated concrete apartment blocks in the classic Soviet style. Like many Cuban farms, there are many and varied tropical tree fruits, and permaculture is easily practiced. Sadly, it wasn’t mango season when I visited, although early-ripening mango varieties were in flower. Here is a fruit tree I lost the name of:
Alamar has 125 workers, with an average age in the “upper middle age” bracket. They produce vegetables and ornamental plants for sale, as well as medicinal and spiritual plants. 90% of their sales are to the public and 10% to hospitals. The Cuban government ensures that hospitals and schools get provided for, I think. They keep bulls (steers?) and rabbits for manure, and oxen and horses for cultivation. Rabbit meat is not popular.
Many of the crop plants are inside shade and/or screen houses, which took quite a hit from Hurricane Irma. Agricultural buildings are mostly pole barns thatched with leaves of the Royal Palm. Thus they can be rebuilt after hurricanes destroy them.
Vegetables are on raised beds. Almost all seed has to be imported and is not organic. Cubans we spoke with generally thought the humid climate would be too hard for seed growing. Personally, I wonder if that’s true. I think a home-grown seed business would be a good step towards more food sovereignty, but it’s not for me to say, really!
Alamar makes their own potting soil from 50% humus, 25% compost and 25% rice hulls. Cubans eat a lot of rice, and annually import 300,000 tons of cheap Vietnamese rice which needs a lot of cleaning.
Alamar is trialing biochar as animal bedding, to reduce smell, and charge the biochar with nutrients and micro-organisms before it is used on the fields. They have insectary plantings (flowering plants to attract beneficial insects and birds) at the heads of many vegetable beds. They use mung beans as a cover crop and to grow bean sprouts.
The tropical “oregano” in the photo above looks nothing like our temperate climate oregano. It is almost a succulent, and the leaves are much bigger than we are used to .
Alamar has tried growing mushrooms, but they are not commonly eaten in Cuba. They also make value-added products: condiments, garlic paste, tomato sauce and pickles. Canning is not easy, as glass canning jars are not available and there are regulations against plastic jars.
They make for use and sale both compost and vermicompost. Below are two photos of open air concrete worm bins, which they cover with tarps.
Another source of income for Alamar is workshops and courses in organic agriculture and tours such as ours. Cuba geared up for a big increase in American tourists during the Obama administration but has seen fewer tourists since Trump introduced stricter criteria for Americans visiting Cuba.
There are several types of agricututal co-operatives in Cuba. Alamar is a Unidad Básica de Producción Cooperativa (Basic Unit of Cooperative Production). In 1993, the Cuban state handed over agricultural land to co-operatives “in usufruct”, which means “the right to enjoy the use and advantages of another’s property short of the destruction or waste of its substance.”
I’ve just got back from a wonderful Agroecology Tour of Cuba with the Organic Growers School. Click the link to sign up for the 2021 tour. I have lots of photos and much to say, but so little time today! In 9 days we visited 9 farms, had several speakers address aspects of life (and particularly farming and environmental issues) in Cuba, had a couple of walking tours, ate many delicious farm-to-table type dinners and still had time for a salsa lesson
We are having trouble with our internet connection today, so this post will either be short or very short.
I’m headed to the Little Rock, Arkansas conference of the Southern Sustainable Working Group
Go to my Events Page for a full list of where to look for me. Not long after getting home from SSAWG I’m headed to PASA in Lancaster, Pennsylvania
Then the West Virginia Small Farms Conference
Then OAK, in Louisville, Kentucky,
Then Organic Growers School in Mars Hill, North Carolina
I have had a little flurry of arranging workshops, so if you have (educational) travel plans, check out my Events page. I’ve also got two interviews lined up, for podcasts, and I’ll tell you about those when they go online.
Use cover crops to feed and improve the soil, smother weeds, and prevent soil erosion. Select cover crops to make use of opportunities year round: early spring, summer, fall and going into winter. Fit cover crops into the schedule of vegetable production while maintaining a healthy crop rotation.
In the Main Conference, on Sat Nov 2, 1.30 – 2.45 pm in the Empire Ballroom E, I have a 75 min workshop
Optimize your Asian Greens Production
This workshop covers the production of Asian greens outdoors and in hoop houses in detail, for both market and home growers. Grow many varieties of tasty, nutritious greens easily and quickly, and bring fast returns. The workshop includes tips on variety selection of over twenty types of Asian greens; timing of plantings including succession planting when appropriate; crop rotation in the hoop house; pest and disease management; fertility; weed management and harvesting.
I will be participating in the Booksigning on Saturday 5.45 – 6.45 pm during the reception
Winter Cover Crops
Cover crops have been much on my mind. Partly it’s that time of year – too late for us to sow oats, not so late that the only option left is winter rye. Here’s my handy-dandy visual aid for central Virginia and other areas of cold-hardiness zone 7a with similar climates.
If you are considering growing winter rye as a no-till cover crop this winter, check out this video:
Rye Termination Timing: When to Successfully Crimp, by Mark Dempsey
“Interested in no-till production, but unsure of how to manage cover crops so they don’t become a problem for the crop that follows?
The most common management concern is when to crimp your cover crop to get a good kill but prevent it from setting seed. Getting the timing right on crimping small grain cover crops like rye isn’t difficult, but it does take a little attention to its growth stage. See this three-minute video for a quick run-down on which stages to look for in order to get that timing right.”
Leanna Smith, in the Staunton News Leader reported that meteorologists in Ohio had spotted something unexpected on the radar on September 10 — a swarm of migrating dragonflies. The radar maps are impressive! The Common Green Darner dragonflies (Anax junius) were reported swarming in Maryland (Sep 11 evening), New Jersey (Sep 12 nighttime) and Virginia (Sep 11 and Sep 12 morning).
She reported that it is common for dragonflies, especially green darner dragonflies, to migrate south in the fall to find warmer weather, but the swarming is unusual. Ohio State University Entomology Professor Norman Johnson spoke toCNN and said that weather conditions can cause the traveling insects to swarm. In 2018, theWashington Post reported that the migration of green darner is typically unremarkable because the insects rarely travel in packs. Although much is still unknown about the migration of dragonflies, we do know that they are very sensitive to temperature. “Climate warming could really disrupt the presence of this migration,” Colin Studds, an animal ecologist at the University of Maryland Baltimore County, told the Post.
It is fairly common for radar to pick up biological movement, especially around sunrise and sunset when warmer air above us can bend the radar beam toward lower elevations where the movement is occurring, according to meteorologistChris Michaels.
On September 10, the National Weather Service of Cleveland, Ohio tweeted about the new development.
Ohio State University entomologist Norman Johnson said the dragonflies are likely Green Darners, which migrate south in the fall. “The insects don’t usually travel in flocks,” he told CNN, “but local weather conditions can cause them to bunch up.” “The big swarms have been recorded a lot over the years, but they’re not regular,” Johnson said.
Details of dragonfly migration are still unclear; researchers have found the winged creatures travel an average of 8 miles per day, but can fly as far as 86 miles.
“A first generation of insects emerges in the southern United States, Mexico and the Caribbean from about February to May and migrates north. Some of those Green Darnersreach New England and the upper Midwest as early as March, says Hallworth, of the Smithsonian Migratory Bird Center headquartered in Washington, DC.
Those spring migrant darners lay eggs in ponds and other quiet waters in the north and eventually die in the region. This second generation migrates south from about July until late October, though they have never seen where they’re heading. Some of these darners fly south in the same year their parents arrived and some the next year, after overwintering as nymphs.
A third generation emerges around November and lives entirely in the south during winter. It’s their offspring that start the cycle again by swarming northward as temperatures warm in the spring. With a wingspan as wide as a hand, they devote their whole lives to flying hundreds of kilometers to repeat a journey their great-grandparents made.
Tracking devices that let researchers record animals’ movements for more than a week or two haven’t been miniaturized enough to help. The smallest still weigh about 0.3 grams, which would just about double a darner’s weight, Hallworth says. So researchers turned to chemical clues in darner tissues. Conservation biologist and study coauthor Kent McFarland succeeded at the delicate diplomacy of persuading museums to break off a pinhead-sized wing tip fragment from specimens spanning 140 years.
Researchers checked 800 museum and live-caught specimens for the proportion of a rare heavy form of hydrogen that occurs naturally. Dragonfly wings pick up their particular mix of hydrogen forms from the water where the aquatic youngsters grow up. Scientists have noticed that a form called hydrogen-2 grows rarer along a gradient from south to north in North America. Looking at a particular wing in the analysis, “I can’t give you a zip code” for a darner, Hallworth says. But he can tell the native southerners from Yankees.
An adult darner, regardless of where it was born, is “a green piece of lightning,” says McFarland, of the Vermont Center for Ecostudies in White River Junction. Darners maneuver fast enough to snap insect prey out of the air around ponds across North America. The front of an adult’s large head is “all eye,” he says, and trying to catch samples for the study was “like hitting a knuckleball.”
Although the darners’ north-south migration story is similar to that of monarch butterflies (Danaus plexippus), there are differences, says evolutionary biologist Hugh Dingle of the University of California, Davis, who has long studied Monarchs, which move northward in the spring in successive generations, instead of one generation sweeping all the way north.
Also, Dingle says, pockets of monarchs can buck the overall scheme. Research suggests that some of the monarchs in the upper Midwest do a whole round trip migration in a single generation. As researchers discover more details about green darners, he predicts, the current basic migration scheme will turn out to have its quirky exceptions, too.”
At least three generations make up the annual migration of common green darner dragonflies. The first generation emerges in the southern United States, Mexico and the Caribbean starting around February and flies north. There, those insects lay eggs and die, giving rise to second generation that migrates south until late October. (Some in that second generation don’t fly south until the next year, after overwintering as nymphs.) A third generation, hatched in the south, overwinters there before laying eggs that will start the entire process over again. These maps show the emergence origins of adult insects (gray is zero; red is many) captured at sampling locations (black dots).
Diagram by Matthew Dodder, M.T. Hallworth et al/Biology Letters 2018
Geek.com reports that this isn’t the first insect invasion of 2019. In June, the National Weather Service’s radar in San Diego picked up a giant crush of ladybugs about 80 miles across in each direction, over southern California. On June 27, residents of northeastern Ohio found themselves dealing with invasive mayflies, which covered cars, houses, and lampposts across Cleveland, Sandusky, and other areas.
Mother Earth News Fair
I had a great time at the Mother Earth News Fair at Seven Springs, Pennsylvania. My first workshop, Lettuce Year Round, was on Friday lunchtime and attendees were still arriving. For those who wanted to hear all about it, but missed it, here is the slideshow:
Note that all the offers of pdfs of my books to download are scams and nothing to do with me! I cannot stop people posting them. It’s almost enough to stop me posting my slideshows, but I know people appreciate another chance to see the slides.
Heritage Harvest Festival
This coming weekend, Saturday September 21, I’ll be presenting Winter Gardening: No Tech to High Tech with Ira Wallace at the Heritage Harvest Festival at Monticello in Charlottesville, VA. Ira will talk about outdoor winter gardening, and I’ll talk about hoophouse growing (which isn’t really that high tech!) It’s Saturday, Sept. 21 at 10:30am in the Heritage Tent. Here’s the LINK. The workshop is for gardeners to learn tips on growing cold-hardy vegetables (and not just kale!) out in the open and with varying degrees of protection from rowcovers, low tunnels, coldframes and hoophouses.
His talk In Defense of Okra is on Friday, Sep. 20th: 1:30–3 pm at the lovely Woodland Pavilion. Click here to buy tickets.
Go if you love okra. Go if you hate it – you might change your mind!
The workshop description says:
Calling all worshippers of this much-maligned, tasty vegetable (that is technically a fruit). And okra doubters beware — we’re about to change … your … life.
Join Smith, author of the newly released book The Whole Okra: A Seed to Stem Celebration, for an interactive and entertaining exploration of the culinary (and non-culinary) uses of okra. Having grown 125 varieties, Smith will share and sample many of the incredible uses of the plant, including okra kimchi, pickled and fermented okra, okra flower tea, okra-seed coffee and okra oil — not to mention the world-renowned delicacy, okra marshmallows.
Participants will learn to enjoy (yes, even LOVE) and appreciate this disparaged underdog — from pod to stem. Take home delicious recipes that will have you profusely apologizing for ever uttering the word “slimy” in its presence.
The future of okra rests on your shoulders. Do the right thing.
Author of The Whole Okra, expert okra enthusiast Chris Smith writes regularly for The Heirloom Gardener, the Mother Earth News blog, and the Farmers’ Almanac blog. His presentations on the versatility of okra have delighted audiences at food and farming festivals and fairs throughout the Southeast. He is the Executive Director for The Utopian Seed Project, Communications Manager for Sow True Seed in Asheville, North Carolina, and serves on the board of The People’s Seed. A native of the UK, Smith has a master’s degree in creative writing from the University of Manchester. His short stories have been published in Nashville Review, Mid-American Review, and The Manchester Review.
Yes, he’s a fellow Brit. He’s very funny. He’s very knowledgeable about seeds and growing vegetables.
Last week I mentioned that while researching potato yield figures, I found an interesting publication, The Potato Association of America, Commercial Potato Production in North America 2010. I’ve been reading that and learning more about potatoes. Here I’m going to focus on harvest and storage, because that’s the bit we’re currently challenged by. I also learned more about planting in hot weather, but that’s for another time.
In England we planted in spring and harvested in October, waiting for the frost to kill the vines. In Virginia we plant in March and June, harvesting in July and October. We have grown Red Pontiac, Yukon Gold and Kennebec here, mostly. They all seem to be determinate varieties. I only just learned there are determinate (varieties with naturally self-limiting growth, generally “early” varieties) and indeterminate varieties (such as “Russet Nugget,” “Nicola,” “German Butterball” and “Elba”). The distinction is explained in Potato Bag Gardening. Growers using towers, grow bags, and cage systems want indeterminate potatoes, which continue to produce more layers of tubers on the stems as they are progressively covered with more soil. Growers wanting a fast reliable crop in the field mostly choose determinate types, which grow as a bush, then flower and die. The Wild Woolly Web does seem to have some contradictory statements about which varieties are determinate and which indeterminate, and some dedicated container growers make assertions not supported by experienced commercial growers. So Reader Beware! I trust Extension and here’s a link to their Ask an Expert page on potato types, and the University of Maryland Extension Home and Garden Info Center Potatoes.
Whether the vines die naturally at the end of their lifespan, or they die of disease, or the frost kills them, or you kill them yourself by mowing or flaming, the potatoes will store better if you then wait 2-3 weeks before harvesting. The potato skins thicken up (becoming more resistant to scrapes and bruises) and the potatoes become higher in dry matter. Harvesting is easier if the vines are well dead. We generally bush-hog ours. Decades ago, in England, we had late blight in the middle of the season, and we cut the tops off and made a very smoky bonfire. (I wouldn’t participate in that much air pollution nowadays!) After waiting for a couple of weeks for the late blight spores to die, we dug the potatoes. The idea was to prevent spores getting on the tubers. As I remember, it all worked out OK.
If at all possible, harvest when the soil moisture is 60-80% of field capacity. Not too dry, not too wet. This reduces damage from scraping. If using a digger, don’t set it digging too deep, or too much soil will be damped on the harvested potatoes.
Tuber temperature will also impact bruise and rot susceptibility. Ideally soil temperature will be 45-65F (7-18C). Because soil temperature lags 3-4 hours behind air temperature rise each day, in cold weather, try to harvest around 6 pm or a bit later. In hot weather, harvest in the morning.
When freshly harvested, potatoes are tender, breathing things. Avoid bruising, which is damage that does not break the skin, by not dropping potatoes more than 6” (15 cm), or throwing them towards a container. Don’t bang them to knock off extra soil.
When harvesting in summer, we stack the crates of potatoes under a big tree overnight to lose some of the field heat before moving them to the root cellar early next morning. Potatoes you take from storage can be no better than the quality of the potatoes you put into storage!
The first part of the storage period is the curing. The potatoes are still actively respiring, so they need a good oxygen supply. Failure to ventilate the cellar enough can lead to Black-heart, where the inner tissue of the potatoes dies and turns black. During the curing period, the skins further toughen up, and cut surfaces and superficial wounds heal over, enabling long term storage. The temperature should be as close to 50-58F (10-14.4C) as you can get. The lower end of the range is best for fresh eating (as opposed to junk food manufacture). Hotter temperatures will promote more rot, and age the potatoes faster, leading to early sprouting. Relative humidity should be 90%, but not 100%! If there is too much condensation, use a fan and open the cellar doors, when temperatures are closest to the goal. Curing takes 10-14 days.
We find that a single thorough sorting after 14 days can remove almost all of the storage problems that are going to happen. Not sorting at this point lets rots spread.
After the curing period, the potatoes become more dormant and do not respire so actively. They don’t need as many air changes as during curing, but if the cellar is too warm, you will need to aerate more. The temperature during the storage period should be 40-50F (4.4-10C), and closer to the lower end of the range is best. Constant temperatures or a steady decline is the goal, not dramatic fluctuations. Humidity should still be 90-95%, to keep weight loss to a minimum.
Potatoes have a natural dormancy of 60-130 days (depending on the storage temperature). After that period, they will start to sprout. Some plant extracts, including clove oil, can add 20-30 days storage, and will then need to be reapplied. I do not know anything about this myself, and do wonder how you remove the clove flavor from the potatoes!
This presentation includes techniques to extend the lettuce season using row covers, cold frames, and hoop houses to provide lettuce harvests in every month of the year. The workshop includes a look at varieties for spring, summer, fall, and winter. Pam Dawling considers the pros and cons of head lettuce, leaf lettuce, baby lettuce mix, and the newer multileaf types. She also provides information on scheduling and growing conditions, including how to persuade lettuce to germinate when it’s too hot.
Learn how to fill your hoop house with productive food crops in the cool seasons. Pam Dawling discusses suitable crops, cold-hardiness, selecting crops, calculating how much to harvest and how much to plant, crop rotation, mapping, scheduling, seasonal transitions, succession planting, interplanting, and follow-on cropping.
Book-signing at the Bookstore Saturday 4.30-5 pm. Buy new books at the Bookstore and bring your grubby used copies to be signed too!
Demos at New Society Publishers booth, of tomato string-weaving and wigglewire system for fastening hoophouse plastic to framework
Friday 3 -3.30 pm, 4.30-5 pm; Saturday 10-11 am, 1.30-2.30 pm; Sunday 9-10 am. 1-2 pm, 3.30-4 pm
Heritage Harvest Festival, Monticello, Charlottesville, VA
Learn tips on growing cold-hardy vegetables (not only kale!) out in the open and with varying degrees of protection from rowcovers, low tunnels, coldframes and hoophouses (high tunnels). We’ll consider crop choices, planting dates and harvesting so there’s always something to eat for everyone from winter market gardeners to small backyard growers. We’ll explain ways to maximize production with succession planting and follow-on cropping.
No extra fee for the workshop, included with the price of general admission
Booksigning:SATURDAY, SEPT. 21st, 11:45am – 12:15pm, MONTICELLO SHOP TENT (WEST LAWN). Buy new books at the Bookstore and bring your grubby used copies to be signed too!
After all this time, my website was due for some spring cleaning. In particular, the old format didn’t work well on smart phones, and this new one does. So I hope that makes life easier for lots of you! I’ve also moved the Categories and Recent Comments so they are easier to find. Let me know if you have ideas for improvements.
It’s cold and rainy here as I write this (almost sleeting). I will need to plug in the heat mats under the pepper, eggplant, cucumber and squash seedlings, cover the tender potted tomatoes and peppers in the greenhouse with rowcover, and pull rowcover over the newly transplanted beds of tomatoes and squash in the hoophouse. I’m expecting a third night with temperatures around 25F (-4C). Hence I’m in the mode of staying indoors and doing some reading. Here’s a big round up of good stuff.
Root Crops and Storage Crops
In A Way to Garden Margaret Roach interviews Daniel Yoder of Johnny’s Seeds on Mastering Root Vegetables. Read, or listen to her podcasthow to grow root crops: Carrots, beets, radishes, parsnips. Lots of tips, and links to more articles/interviews
An earlier article discusses how to store garden vegetables for winter. Margaret covers the basics of temperature and humidity, along with details of some crops and ideas for preserving crops that don’t store well.
Ticks and Tasks in Virginia
The Garden Shed is a monthly online newsletter published by the Piedmont Master Gardeners. It provides all gardeners in Charlottesville-Albemarle County area of Virginia with a science-based, reliable source of gardening information, monthly tasks and tips, and other gardening related features. Here are a couple of the most recent ones:
Note that the link in this article to VCE Publication 246-480 “Vegetables Recommended for Virginia,” does not work. It looks like the Extension has taken the publication down. Ralph Morini suggests that the next best reference is 426-331 Vegetable Planting Guide and Recommended Planting Dates
This post by Craig Wallin for the Profitable Plants Digest gives info on lavender, gourmet mushrooms, woody ornamentals, landscaping trees and shrubs, bonsai plants, Japanese maples, willows, garlic, bamboo and herbs. I’ll add a big caution about bamboo, as we have found many bamboo varieties very invasive and hard to control. Links on the site provide info on ginseng, microgreens and more.
Urban Gardening 101: How to Deal with Contaminated Soil It’s hard to find much information on this topic for organic gardeners, although Leah Penniman does also offer help in her book Farming While Black
Al Jazeera, in their Witness series, has a 25 minute film The Seed Queen of Palestine Can one woman’s mission to revive ancient heirloom seeds inspire a celebration of traditional Palestinian food? Vivien Sansour is distributing rare, ancient heirloom seeds to Palestinian farmers. Click hereand search for The Seed Queen of Palestine
Join more than 6,000 other naturalists across the nation in taking the pulse of our planet. You’ll use scientifically-vetted observation guidelines, developed for over 900 species, to ensure data are useful to researchers and decision-makers. On their website, learn about the National Phenology Network Pest Patrol which is seeking observers to report their sightings of insect pest species that cause harm to forest and agricultural trees. Your observations as part of this campaign will help validate and improve the USA-NPN’s Pheno Forecasts, which help managers know when these species are active and susceptible to treatment.
Heed the Warnings for Agriculture from the Fourth National Climate Assessment
The U.S. Global Change Research Program has released the Fourth National Climate Assessment, an examination of the effects of climate change on the United States. Chapter 10 of the Assessment is on “Agriculture and Rural Communities.” This chapter contains four key messages regarding productivity decline, resource degradation, livestock health, and rural-community capacity to respond.
The Texas High Plains and Southern Plains continue to experience reductions in irrigation water from the Ogallala Aquifer as water levels decline, and producers need some way to improve their revenue from their farming systems. They have the potential to get a pretty good return and be able to take better advantage of the water they do have, using high tunnels to grow regular vegetable crops and also use them for seed production, cut flowers, small fruit.
Bug Tracks Charley Eiseman Life in a Cubic Foot of My Lawn. This inspiring article is one of many by this expert in leaf miners as well as other insects. It’s such fascinating stuff! And his photos are exquisite. There are over 40 in this post!
Learn about Vegetable Grafting
Members of a Specialty Crops Research Initiative Grafting Project Team have organized a grafting webinar series. The webinars each cover a different topic about the science and technology of vegetable grafting. While not specifically about organic production, upcoming topics that could be of interest to organic growers include Grafting to Increase Production for Small-acreage and High Tunnel Tomato Growers, by Cary Rivard of K-State University; past topics include Making Grafting Affordable and Beneficial to US Growers by Richard Hassell of Clemson University. Past presentations in the series were recorded and archived. Find the recordings on the project YouTube channel here, and learn more about upcoming webinars here.
See Enhancing the Utility of Grafting in US Vegetable Production, by Matthew Kleinhenz of the Ohio State University, below.
If you are a gardener, you may be interested in another webinar by Cary Rivard about grafting for home gardeners: Demystifying Grafted Tomatoes: The Why & How for Gardeners, which is part of the 2019 series of Advanced Training Webinars for Master Gardeners sponsored by Oregon State University Extension. Find out more informationhere.
Read up on New Research
eOrganic recorded presentations on current organic research from the Organic Research Forum organized by the Organic Farming Research Foundation at Organicology. The following presentations are freely available now and more will be added to their playlist on the eOrganic YouTube channel and mentioned in upcoming newsletters. Find the program here and click here to find the recordings on a YouTube playlist.
Sorry for the delay in posting this. Apparently a driver hit an all-important cable and the whole county is without internet. Rural living can’t be beat!
Here we are in March. Nothing new to harvest outdoors yet, although the garlic scallions are getting close. But the hoophouse is serving us well. Every day we harvest 5 or 10 gallons of salad mix and either some cooking greens, radishes or scallions. The photo above is a new delight: Pink Stemmed Mizuna from Osborne Seeds
We’ve finished the hoophouse turnips, and are now making serious headway on the kale. We grow both Red Russian and White Russian kales.
We use orange flags to denote where to harvest next, as we have a large hoophouse (30 x 96 ft) and many different crops. It is often obvious as we get closer. Here’s three different ways we are harvesting right now:
As you can see we harvest baby lettuce mix by cropping it about an inch above the soil. I think this is the third cutting of this patch. I like to make our salad mixes about one third lettuce, one third brassicas of some kind and one third spinach. The brassica mix below is now bolting, so I pulled it up as I harvested. All brassica flowers are edible, and the buds are just like tiny broccoli.
The spinach I’m harvesting today is our third sowing, and we are cutting outer leaves and chopping them into the salad mix.
For those wondering what the silver stuff is: these three crops are all in our narrow north edge bed. We have 24″ (60cm) bubblefoil insulation stapled onto the hipboard. It reflects back both light (in short supply low on the north wall) and heat.
In the greenhouse we have reached Peak Broccoli Flats season. We have 16 flats for our first planting in the coldframe, 16 of the second and four of the (backup plan) third sowing in the greenhouse.
We use open wood flats for these kinds of hardy seedlings. We sow 4 rows into 12 x 24 x 3″ flats and then spot out into 12 x 24 x 4″ flats (40 plants each) to grow to final transplant size.