Collards are a southern food icon and an underappreciated nutrition powerhouse that has sustained generations of southerners, both Black and white. At last this vegetable is getting the recognition it deserves! The first ever Collards Week is happening December 14-17 2020. I found out about this while researching for an article on collards for Growing for Market magazine. Yes, perhaps the title “Week” is aspirational, and four days is a jumping-off point for the post-Covid future.
There will be online presentations celebrating collards led by Michael Twitty, Ira Wallace, Jon Jackson, Amirah Mitchell and Ashleigh Shanti. This event includes food history, seed stewardship, gardening, farming, cooking and conversation and is part of the Heirloom Collard Project. Collards Week is a collaboration between the Culinary Breeding Network and The Heirloom Collard Project. You can register for free at www.heirloomcollards.org/collard-week-2020/. All events will be broadcast live through The Culinary Breeding Network’s YouTube channel starting at 1:00pm Eastern time.
Michael Twitty’s kick-off presentation, The History and Significance of Collards in the South, will be a fascinating exploration of complex issues. Twitty states this himself on his blog, Afroculinaria, “The collard’s complicated story with African Americans really speaks to the way food can unravel the mysteries of complex identities.”
The Collards Tour and the Book
From 2003 to 2007, a team of four crisscrossed the South, mostly in North and South Carolina, searching for heirloom collards by word-of-mouth, by spotting them as they drove past, and by reading newspapers, attending small-town collard festivals, and visiting restaurants where collards were the only greens served. After the trip, USDA Plant Geneticist Mark Farnham grew out more than sixty of the heirloom collard cultivars in a trial garden at a USDA Agricultural Research Station. He published several papers, including the 2007 article “Neglected Landraces of Collard from the Carolinas.”
Two of the other road trip members, Edward H Davis and John T Morgan of Emory & Henry College, wrote a beautiful book: Collards: A Southern Tradition from Seed to Tableto tell the stories of these varieties and the gardeners who steward them. Davis and Morgan noted that despite other wide diversity among the collard seed savers, most of them were older, with an average age of 70, and most of them had no family, friends, or neighbors willing or able to keep growing their special family collard variety into the future.
The Heirloom Collards Project
In 2016, Seed Savers Exchange in collaboration with Ira Wallace at Southern Exposure Seed Exchange requested over 60 collard varieties from the USDA ARS National Plant Germplasm System (NPGS) to trial at Seed Savers Exchange, Decorah, Iowa. These were rare heirloom varieties collected by Davis and Morgan from seed savers across the Southeast. The goal of the Heirloom Collards Project is to support the tradition of heirloom collards, by finding growers and sharing the seeds nationally and also to celebrate the special stories associated with these heirloom collards.
Ira Wallace has an article “A Southern Food Tradition: Saving Heirloom Collards” coming out in the Jan/Feb 2021 issue of Grit magazine. There she points out that giant seed companies have been buying out the smaller ones, and have reduced the number of open-pollinated collard varieties readily available to only five.Saving heirloom collards is an act in food heritage. Ira’s article also includes some collard stories and directions for growing seed. You can also find good directions for growing seed in Jeff McCormack’s Organic Brassica Seed Production Manual.
Mosaic photo by Chris Smith
The Heirloom Variety Trial
The National Heirloom Collard Variety Trial was launched in 2020, with over 230 participants across the US. They are currently growing twenty different varieties from the large collection at Seed Savers Exchange and the USDA. This collection includes varieties from the Davis and Morgan collecting trips. There areeight trial sites growing all 20 varieties and also hundreds of citizen scientists growing and comparing randomly selected sets of three varieties.The growers are recording data for each collard variety on appearance, uniformity, vigor, disease resistance, flavor, germination, earliness, yield and winter hardiness. Their data will be recorded and analyzed via SeedLinked, a web platform connecting people with information on varieties written by people growing them.
The Heirloom Collard Project has a place for everyone interested in growing or eating this delicious vegetable, including home gardeners, experienced seed savers, commercial growers and chefs. Click the link to see photos of the 2020 varieties and the farms doing the full trial. Get ready to sign up for 2021. Novice seed growers may want to consider practicing with more common varieties first, and then, as they gain experience, they can sign up to become seed-saving stewards.
Collards are very easy to grow and harvest, providing months of harvests from a single sowing. They are cold-hardy and heat-tolerant, giving the possibility of harvests ten months of the year in the Southeast. Colder areas may need to provide some protection if wanting mid-winter harvests. Hotter areas may need a longer summer break. Growers can make sauerkraut to extend the season. There is a wide range of leaf shapes and colors including variegated types. For details of how to grow collards, see my article coming soon in Growing for Market.
Growing Collard Seed
Like other brassicas, collards are a biennial seed crop. To save seed, keep your collard plants alive over winter. If you can’t do this outdoors or in a hoophouse, dig up the plants in late fall and trim off the leaves, preserving the growing point. Replant these plant stubs (stecklings) close together in a tub of soil or even damp sawdust, to replant in early spring. Make sure you have no other brassicas from the oleracea group (Brussels sprouts, cabbage, cauliflower, some kales, kohlrabi) in flower at the same time. Some kales (Russian, Siberian types) are Brassica rapa and do not cross-pollinate.
Last week I wrote about Winter Preparations for Vegetable Gardens. For those with a hoophouse, here are some notes on all the work we can do to grow winter crops there! For those without a hoophouse as yet, scroll to the end for Twenty Benefits of Having a Hoophouse
First, a roundup of previous blogposts on winter hoophouse topics.
Planning winter hoophouse crops includes a description of how we do our hoophouse crop planning so we can maintain a crop rotation and still pack the beds fully with hardy crops.
After the set-backs with our winter hoophouse greens transplants that I wrote about in Hoophouse fall bed prep Plans A-D and spider-webs, we worked really hard and got the whole house planted up. Most of the transplants have recovered from their transplant shock (wilting each day), during the cloudy weather we had.
The new seedlings are coming up fast and calling on us to thin them. We ended up not needing so many of the Plan D plug flat plants, but we’ve kept them for now “in case” .
Ultimately if we don’t need them, they’ll go in a salad mix. I wrote about Making baby salad mix last year. The past two days I have been able to harvest a mix in the hoophouse. The ingredient we are shortest of is lettuce. My first mix was spinach, Bulls Blood beet leaves, a few leaves of Tokyo Bekana, Bright Lights chard, Scarlet Frills, Ruby Streaks and Golden Frills, and a handful of lettuce leaves Red Tinged Winter is growing fastest, of all the varieties we planted this year.
In the winter 2019-2020, a reader in the Pacific Northwest wrote: “This winter I have been re-thinking my crop rotation plan after having some issues (with flea beetle larvae in the soil outsmarting my diligent insect netting of my brassica salad crops). These days I see intensive market gardeners seeming to not worry so much about rotation (i.e. Neversink farm, etc), and yet I’ve always been taught that it is such an important principle to follow. I reviewed your slideshows on crop rotation and also cool crop planning in the greenhouse (which briefly addresses salad brassica rotation with other crops). With how much space I have and the high demand I have for brassicas, for salad mix (mustards) and also the more mainstay cole crops, I had settled on a 2.5 yr between brassica crop rotation (but planting two successions of mustards in the same bed within one year, in the year the bed was in mustards, with a lettuce or other crop breaking up the successions, with the idea that they were very short day and also light feeder crops). Wondering if you think this just doesn’t sound cautious enough, or if this sounds like a reasonable compromise with not having more space to work with (and wanting to satisfy the market demand for brassicas).”
I replied: “Yes, I do think crop rotation is important. I do know some farms seem to have given it up. I think what you are seeing shows one reason why rotation is important. In our hoophouse, we do as you do, allocating brassicas to a space for that winter season and perhaps doing more than one round of brassica crops. Then moving away from brassicas for the next two winters. If doing that doesn’t get rid of the flea beetle problem, and you are being thorough about netting with small-enough mesh netting (sounds like you are, but maybe check the mesh size), then my next step would be spinosad when the flea beetles appear. You can spray the inside of the netting too, and close it quickly. It’s that or a longer rotation, which it sounds like is not financially viable. You could also try farmscaping and/or importing predatory insects (not sure if there are any), Are there beneficial nematodes that attack flea beetle larvae? These are things I don’t know about, but might be worth looking into.”
Doing a spot of research today, I find that Heterorhabditis bacteriaphora, (Hb nematodes) a beneficial nematode fromArbico Organics will attack flea beetles. also known as NemaSeek, and sold separately. This is the wrong time of year for introducing nematodes in most of the US. They need warm weather to thrive.
Another suggestion from Arbico is BotaniGard Maxx & other B. bassiana sprays, which infect and kill adult flea beetles. Repeat applications as needed throughout the growing season.
For those of you wistfully thinking about a hoophouse, let me help you a step closer to having one next year! Sales of my Year-Round Hoophouse book are doing well, which suggests to me that quite a few gardeners and growers are thinking in this direction.
Twenty Benefits of Having a Hoophouse
An extended growing season because plants are protected from cold weather.
Faster growth and higher total yields.
Beautiful unblemished crops not battered by the elements.
Fewer foliar diseases because the leaves can stay dry.
Crop survival at lower temperatures in the hoophouse than is possible outdoors.
Better crop recovery in winter due to warm sunny days following the cold nights.
Some protection from deer and other pests large and small.
Soil temperature stays above 50F (10C) in zone 6b. Warm soil = faster cold weather growth.
Higher proportion of usable crops – more food, higher sales dollars.
Diverse crop portfolio – grow crops that wouldn’t succeed outdoors in your climate.
Harvest whenever you need the crops, even during pouring rain!
Wonderful working conditions – no need for gloves and hats; take off your coat.
A food garden on a manageable scale.
A place to enjoy practicing intensive food production.
The chance to have an area completely free of weeds – new weed seed doesn’t blow in.
No need to work with heavy machinery.
Much better value for producing crops (per dollar invested) than a heated greenhouse.
Can be constructed by generally-handy people. Specialists are not needed.
Ecological energy use. The embodied energy of the plastic is less than the energy that would be used to ship similar produce from somewhere warmer (Eliot Coleman, Four Season Harvest). Another study found this was not true for smaller (9 x 12 m) hoophouses – although the economic incentive for growers is still true, there is no energy efficiency advantage to the planet. Smaller carbon footprint: shipping 1 kg lettuce has 4.3 times the CO2 footprint of locally grown hoophouse lettuce. Plawecki, R., Pirog, R., Montri, A., & Hamm, M. (2014). Comparative carbon footprint assessment of winter lettuce production in two climatic zones for Midwestern market. Renewable Agriculture and Food Systems,29(4), 310-318. doi:10.1017/S1742170513000161.
Know your climate
The WeatherSpark website provides “The Typical Weather Anywhere on Earth”. Enter your nearest town or airport and you get clearly explained info with fascinating graphics of how the weather goes over the year in your locality. Note this is not a forecast site, it’s about average weather for each place. Useful to people who’ve recently moved and want to know what to expect this winter, or to new gardeners who haven’t paid so much attention previously. Or to those who want to check their assumptions (I really thought the wind was out of the west more of the time than records say). There are charts of high and low temperature, temperature by the hour each month, cloud cover, daily chance of precipitation (both rainfall and snowfall), hours of daylight, humidity, wind speed and direction and solar energy. A big help in making wise decisions. I know that climate change is going to cause havoc with averages, and we’ll need to learn to become better weather forecasters individually, and to use soil temperature and other metrics to decide when to plant. This website explains things well.
Winter gives a time for most of us to ponder success, failure, and possibilities for doing things differently.
My annual blogpost of Winter-Kill Temperatures for Cold-Hardy Vegetables is always very popular. In fact, it’s my most popular title! Usually searches for this info increase in October and peak in early November, so here are quick links for those of you who have been meaning to look something up.
For several years, starting in 2012, my friend and neighboring grower Ken Bezilla of Southern Exposure Seed Exchange and I have been keeping records of how well our crops do in the colder season. Ken provided much of the original information, and has suggested the morbidly named Death Bed idea: set aside a small bed and plant a few of each plant in it to audition for winter hardiness. Note each increasingly cold minimum temperature and when the various crops die of cold, to fine-tune your planting for next year (and leave me a comment!) Each year I update the list, based on new things I learned during the recent winter.
We are in zone 7a, with an average annual minimum temperature of 0-5°F (-18°C to -15°C).
The winter 2019-2020 was mild, with our lowest temperature being a single night at 12°F (-11°C). The Koji greens became completely unmarketable but did not completely die. Yukina Savoy is indeed hardier (as I expected), 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). That 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. I also added some cover crop hardiness temperatures.
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. Also 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 row cover to protect them against cold drying winds.
It’s worth noting that in a double-layer hoophouse (8F/5C warmer at night than outside) plants can survive 14F/8C colder than they can outside, without extra rowcover; at least 21F/12C colder than outside with thick rowcover
Salad greens in a hoophouse in zone 7 can survive nights with outdoor lows of 14°F (-10°C). A test year: Lettuce, Mizuna, Turnips, Russian kales, Senposai, Tyee 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.
Seeking Reader Participation
Your experience with your soils, microclimates and rain levels may lead you to use different temperatures. I’d love to hear from readers if they’ve found my numbers work for them, or if they have a different experience. You can leave a comment here, and it will appear on the website, for others to consider. Or you can fill out a Comment Page and only I will see it, although I’ll pass on the information without your name, if I think others would like to know too.
Preparing for Frost and Cold Weather. This post includes our Frost Alert Card, a Frost Predictions checklist of what to do when the first fall frost is expected; how to use sprinklers overnight to stop tomatoes from freezing; four ranges of cold-hardiness (some crops can wait in the garden till it gets colder); and different levels of crop protection, including rowcover, low tunnels, Quick Hoops, caterpillar tunnels and hoophouses (aka high tunnels).
Season Extension and Frost Preparations. This post includes my Season Extension slideshow; the Frost Alert Card and Frost Predictions checklist again; a diagram of our winter double hoop system to hold rowcover in place during the worst weather;
Changing Winter Temperatures
Here’s an article from the Virginia Mercury by Sarah Vogelsong, giving info about changing winter temperatures, particularly later fall frosts in Virginia:
Autumn’s first frost is falling later. For farmers, the consequences are wide-ranging
by Sarah Vogelsong, November 3, 2020
Halloween has come and gone. The clocks have been set back. Every evening darkness falls just a little bit earlier.
But for much of Virginia, the first frost still remains elusive.
Over the past century, the average date of the first frost has been moving progressively backward throughout the commonwealth, today landing a week or more later than it did at the turn of the 20th century.
“This is one of the clearest signs of not only the changing climate but … its impact on our systems,” said Jeremy Hoffman, who as chief scientist at the Science Museum of Virginia conducts extensive research on climate change in Virginia. “It’s not just here, it’s everywhere.”
As global temperatures have warmed, largely due to the release of greenhouse gases into the atmosphere, frost seasons have shrunk. The Fourth National Climate Assessmentreleased by the Trump administration in 2018 reported that “the length of the frost-free season, from the last freeze in spring to the first freeze of autumn, has increased for all regions since the early 1900s.”
How the shifts have played out in different states with different geographic, ecological and topographic features varies. Data from the U.S. Environmental Protection Agency show that between 1895 and 2016, the average date of the first fall frost moved back by 7.1 days in Virginia.
On the local level, the changes may be even starker. Estimates of how much the average date has changed vary depending on the time range used and how scientists fit a line to their data points, but in most Virginia cities, they show unmistakable upward trends. Looking at first frost dates between 1970 and 2016, Climate Central, a nonprofit staffed by scientists and journalists, calculated that on average, the first frost today is 5.9 days later in Lynchburg, 8.9 days later in Harrisonburg, 12.8 days later in Roanoke, 15 days later in Charlottesville and 18.5 days later in Richmond. While their data show Norfolk’s first frost occurring about six days earlier on average, Hoffman said that longer-range data going back to 1940 show the first frost moving back by about five days. Still, he cautioned, variation does occur: “Localized things like weather” can “work against that dominant signal in datasets like these.”
The implications of the shifts in the freezing season go beyond a few more days to enjoy warm weather, say scientists and policymakers. Perhaps most affected are farmers, whose livelihood is intimately tied to fluctuations in both short-term weather and long-term climate.
“Some things you can sort of manage around and some things you can’t,” said Wade Thomason, a professor of crop and soil environmental science at Virginia Tech and the state’s grain crops extension specialist.
For most farmers, the last frost of the year in the spring is the riskier of the season’s two endpoints, falling as it does when most plants are young and more vulnerable to temperature extremes. But ongoing changes in the first frost in the fall also have ripple effects.
“It can be a beneficial thing for some instances. We might get more grazing days for livestock operations in a year,” said Thomason. For some crops, like double-cropped soybeans that are planted following the harvest of another crop — typically a grain like wheat — “it can extend the season.”
Other effects are less immediately apparent. Many wheat farmers who typically plant in mid-October have begun to push back their planting dates to ensure plants don’t grow too quickly during the freezing months, making them susceptible to disease or falling over in the field. Specific types of forage rely on long periods of cool weather to thrive: in Northern Virginia and the Shenandoah Valley, farmers have noticed that orchard-grass stands are only living for four to five years instead of the once-standard 10.
“For years now, we’ve heard from farmers that the stands don’t persist like they used to,” said Thomason. Research has shown that one factor contributing to less persistence is warmer nighttime temperatures, he added, but because most operations rely on cultivars developed decades ago, “we haven’t adapted orchard grass that thrives in a warmer climate.”
Other crops affected by longer warm seasons? Tree fruits and wine grapes
“Virginia’s one of those places that we expect to get hotter and we also expect to get wetter,” said Benjamin Cook, a climate scientist with the National Aeronautics and Space Administration’s Goddard Institute for Space Studies whose research includes the effects of climate change on vineyards. Neither of those conditions are necessarily good for high-quality wine prospects, he said. Furthermore, farmers working in these areas face special risks because of the long time to maturity of their crops.
“Those are parts of the agricultural world that adaptation eventually becomes a lot more challenging, because you can’t switch crops from year to year,” he said. “You have to make a bet on something and wait four years to see if it pays off.”
Regardless of their specialty, all farmers face another consequence of shorter freeze seasons: more weeds and more pests.
“With longer growing seasons, with these warmer winters, the populations of insects are increasing, the mortality is lower, they can produce more generations a year, and that potentially presents a problem for agriculture and plants in general,” said Cook.
Those effects can be seen on the ground, said Thomason: “Maybe 30 years ago, we could stop worrying about them in early October, and now it may be a week or 10 days later.”
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Root Crops to Plant in Central Virginia in November
We have reached the slow-growing time of year. We have passed our last chance to sow root crops outdoors. Nothing changes fast. Reread Root Crops in October for more ideas, if you are in a warmer climate zone than us. We are in Winter-hardiness zone 7, which has overall minimum average of temperatures of 0° to 10°F (-18°C to -12°C). We are in subzone Zone 7a, with a minimum average temperature of 0° to 5° F (-18°C to -15°C).
In late November, we sow our fourth radishes in our hoophouse. See Root Crops in September for more about our succession of hoophouse radish sowing dates. We sow Easter Egg, and White Icicle. It is too late for us to sow Cherry Belle or Sparkler types – they get too fibrous. This sowing will feed us for the month of February. Unlike the late October sowing which lasts for 8 weeks, this sowing will only be good for 4 weeks.
See Root Crops in September for information on figuring sowing dates for winter hoophouse succession crops (radishes are the example)
In early November (around 11/9), we often sow our second of three plantings of hoophouse turnips. We sow Hakurei,Early White Egg,Oasis, and Red Round. These will be harvested 2/25-3/10 (with thinnings for greens from 1/11).
Sometimes we make our second sowing in late October, if we have space available then and want bigger turnips. We may make a third turnip sowing in very early December if space opens up then. The third sowing is only worthwhile if thinned promptly and eaten small, as the plants will start bolting in early March.
Root Crops to Harvest in Central Virginia in November
If you are unsure how soon temperatures will drop in your area, see Weatherspark
Enter your city, airport or zipcode and you’ll get access to helpful graphics on seasonal temperatures, cloud coverage, rainfall, snow, sunshine, humidity, wind, water temperature at nearby large bodies of water. Also tourism, which I had not previously thought of as a type of weather! After that comes an assessment of growing conditions (considered only as days without frost) and growing degree-days, solar energy, and more.
In Louisa County, where we are, the average daily low temperature in November makes a precipitous but erratic slide from 45°F (7°C) to 36°F (2°C), with a small chance of going as low as 24°F (-4°C) by the end of November. Most of our root crops other than sweet potatoes and potatoes can wait to be harvested until late November, but we would rather proceed with harvesting and storing, as the daylight gets shorter and the chance of cold, wet working conditions get higher.
We continue clearing root crops outdoors and storing them (in this order):
·25°F/-4°C, bulb fennel
·20°F/-7°C, turnips, winter radish, celeriac
·15°F/-9°C, kohlrabi, beets (15-20°F/-9 to -7°C, depending on variety)
·12°F/-11°C, carrots, Cylindra beets
·10°F/-12°C, parsnips, probably OK to 0°F (-18°C)
·Horseradish is not killable by cold temperatures, as far as I can tell. But if the ground is frozen, you can’t dig it up.
Wash and store roots in perforated plastic bags under refrigeration, or in a root cellar or other cold storage place.
Our 9/6 sowing of hoophouse radishes will have finished and our second sowing will mature and brighten our meals from 11/6 to 12/25 approximately. Our first sowing of hoophouse turnips (10/15) will produce edible little roots as thinnings later in the month.
Other Root Crop Tasks in Central Virginia in November: Long term storage of sweet potatoes and white potatoes
After curing, store boxes of sweet potatoes at 55-60°F (13-15.5°C), 50-60% humidity.Curing is complete when the skin is undamaged after rubbing two together. If the heating in your curing space is variable, be sure to check several boxes of sweet potatoes closer to and further from the heater. We once had a sad thing happen after a new heater had been installed. We were checking the most accessible boxes only, not the ones at the back near the heater. We got wrinkly sweet potatoes. If your crop is not curing as fast as you hoped, check the temperature, and do what you can with fans to move the air around without blasting directly on any particular box. Also check the humidity and adapt as needed. We found that splashing water directly on the concrete floor of our basement was the most successful method.
Restack the boxes (in a rodent-proof storage cage, if you are using an outbuilding).
Peruvian (“white”) potatoes
Potatoes stored in crates in our root cellar.
Photo Nina Gentle
Root Cellar: Cool to 50°F (10°C) after one month, then 40°F (4.5°C), airing once a week or less if cooling not needed. See Special Topic for July
Special Root Crop Topic for November in Central Virginia Vegetable storage without electricity.
·Meeting the storage requirements of various crops helps maximize their season of availability
·Some vegetables need to cure before storage and the curing conditions are different from those needed for storage. Curing allows skins to harden and some of the starches to convert to sugars.
·Many crops may be stored without electricity, perhaps in buildings that serve other uses at the height of the growing season.
·Washington State University Extension’sStoring Vegetables and Fruits at Home, is a good introduction to alternatives to refrigerated storage, using pits, clamps and root cellars. Drawings below are from WSU Storing Vegetables and Fruits at Home
·Also old versions of the USDA Agriculture Handbook 66.
Four Sets of Storage Conditions
By providing storage spaces with 4 types of conditions, 25 crops can be stored.
·In my chart in Sustainable Market Farming, the Summary column indicates the general conditions needed for each crop, and allocates each crop to one of 4 groups:
·A=Cold and Moist: 32°F–40°F (0°C–5°C), 80%–95% humidity — refrigerator or winter root cellar conditions. Most roots, greens, leeks
·C=Cool and Dry: 32°F–50°F (0°C–10°C), 60%–70% humidity — coolerbasements and barns. Garlic and onions
·D=Warm and Dry to Fairly Moist: 50°F–60°F (10°C–15°C), 60%–70% humidity — basements. Sweet potatoes and winter squash.
Winter squash and pumpkins – storage
We built a rodent-proof cage with wood shelves. You could use shallow crates to avoid handling each individual squash.
Depending on the severity of your winter, some cold-hardy root crops (turnips, rutabagas, beets, carrots, parsnips, Jerusalem artichokes and horseradish) and also leeks can be left in place in the ground, with about 12” (30 cm) of insulation (straw, dry leaves, chopped corn stalks, or wood shavings) added after the soil cools to “refrigerator temperatures.”
Hooped rowcovers or polyethylene low tunnels can keep the worst of the weather off. There could be some losses to rodents, so experiment on a small scale the first winter to see what works for you. We have too many voles to do this with carrots or turnips.
Besides being used as a method for storage of hardy crops deep into winter, this can be a useful method of season extension into early winter for less hardy crops such as beets, celery and cabbage, which would not survive all winter this way. Access to crops stored in the ground is limited in colder regions — plan to remove them all before the soil becomes frozen, or else wait for a thaw.
Storage clamps (mounds)
Cabbage, kohlrabi, turnips, rutabagas, carrots, parsnips, horseradish, Jerusalem artichokes, salsify and winter radishes (and any root vegetables that can survive cold temperatures) can be stored with no electricity, by making temporary insulated outdoor storage mounds (clamps).
Mark a circular or oval pad of soil, lay down straw, pile the roots up, cover them with straw and then with soil, digging a drainage ditch round the pile. For ventilation, leave a tuft of straw poking out. Slap the damp soil in place to protect the straw and shed rainwater.
For the backyarder, various roots can be mixed, or sections of the clamp can be for different crops. Those growing on a large scale would probably want a separate clamp for each crop. It is possible to open one end of a clamp or pit, remove some vegetables, then reseal it.
There is a balance to be found between the thermal buffering of one large clamp and the reduced risk of rot that numerous smaller clamps provide.
Pits and trenches
Dig a deep, wide pit (3+ feet deep) in a dry area where water will not stand, lining it with heavy plastic and straw. Alternate layers of vegetables with layers of straw, finishing with straw. Put a loose sheet of plastic on top, (not sealed down). Cover with more soil.
To deter rodents, bury large bins such as (clean) metal trashcans, layer the vegetables inside with straw, and cover the lid with a mound of more insulation and soil.
Or bury insulated boxes in the ground inside a dirt-floored shed or breezeway. A new life for discarded chest freezers! Insulated boxes stored in unheated areas need 6-8” (15–20 cm) of insulation on the bottom, sides and top.
Root Cellars for crops needing cool, damp conditions
·Potatoes do best in a dark cellar, at 40° – 50°F (5° -10°C). With a good in-ground root cellar, potatoes store for 5-8 months. Ventilate as needed, to maintain the cellar in the ideal range.
·Below 40°F (5°C) the starches convert to sugars, giving potatoes an unpleasant flavor and causing them to blacken if fried.
·Root cellars can be used for apples, cabbage, or root vegetables, but be careful what you mix.
·Some people pack the unwashed roots in boxes of sand, wood ash, sawdust or wood chips. Perforated plastic bags or crates are easier.
·Pepper plants can be hung upside down in a cellar to ripen, or store. Cabbage can also be hung upside down.
·Cabbage, celery, leeks can be replanted side by side in boxes or tubs of soil.
Ethylene is generally associated with ripening, sprouting and rotting. Some crops produce ethylene gas while in storage — apples, cantaloupes and ripening tomatoes all produce higher than average amounts. Environmental stresses such as chilling, wounding and pathogen attack can all induce ethylene formation in damaged crops. Some crops, including most cut greens, are not very sensitive to ethylene and so can be stored in the same space as ethylene-producing crops. Other vegetables, however, are very sensitive to the gas and will deteriorate in a high-ethylene environment. Potatoes will sprout, ripe fruits will go over the top, carrots lose their sweetness and become bitter.
Cuban Agroecology Tour: Finca Agroecológica El Paraiso, Viñales
Here’s another post from my January 2020 group agroecology trip with Organic Growers’ School to Cuba. I’m posting about this sporadically as I organize my photos and journal.
Day 5 – Saturday January 11 lunch and afternoon
After visiting La Palma, a farm in Pinar del Rio province primarily growing tobacco, and Manolo Tobacco Farm to see cigars made, we went to a farm restaurant called La Finca Agroecologica el Paraiso. Wilfredo is the main farmer and his daughters are the main chefs.
The farm has 8.9 hectares, with 200 vegetable beds and 80% of the produce is sold through their restaurant, and 20% to hospitals etc (I think that is a legal requirement in Cuba). The restaurant is at the top of the hill, affording beautiful views of the farm.
We had an exceptionally delicious lunch starting with an anti-stress herbal cocktail. Following that we had squash soup, sweet potatoes, taro, squash, lettuce, cabbage, cucumbers, pickled beans, pickled cucumbers, pork, beef, fish, rice and beans. The most vegetables I ate all week! (Food for tourists tend to be meat focused, although the places we visited could cater for vegetarians and vegans.) We enjoyed flan for dessert.
After lunch we were given a guided tour of Finca Agroecológica El Paraiso. The boxed beds were very tidy, and they are all hand watered with water pumped from the river.
Creole spinach – see photo above. I do not know the Latin name for this vegetable, and in my research of hot weather cooking greens, particularly alternatives to spinach, I had not come across this crop before. Leave a comment if you know what it is.
Their “summer lettuce” is Tokyo bekana or maruba santoh. This use of the fast-growing chartreuse tender-leaved Asian green for a salad leaf was one I saw several times in Cuba. I thought I’d invented it! Haha! One summer when our lettuce did not grow according to plan, we served some Tokyo bekana as lettuce, and many people did not notice a difference! (Enough salad dressing will mask any vegetable flavor!) Some farms and restaurants simply call it “lettuce” or “summer lettuce”, some say it is a kind of pak choy, and a few can provide the actual name.
The farm grows aromatic herbs to deter bugs. They use tobacco stem solution to kill pests. Nicotine is a strong generalist poison, which used to be part of the toolkit of organic growers here in the US and in the UK. It has the advantage of being short-lived, so produce can be eaten the day after spraying.
See this video from Franny’s Farmacy. Made by two of my fellow travelers on the OGS Tour.
There are several aspects of vegetable harvesting. In this post I will look first at maturity indicators, then at four ranges of cold-hardy crops for harvest at various stages of winter, followed by a reminder of the order for harvesting storable crops, according to the coldest temperature they can take. After that I have links to a couple of other websites with great information on these topics, a mention of two articles on seed saving and one on garlic planting I have in Growing for Market magazine. And a link to a Mother Earth News Fair Online workshop on establishing winter cover crops.
Harvest and Maturity Indicators
Don’t harvest too soon or too late. How do you know when it’s ready to harvest? Different factors are important for different crops. Use all your senses.
Size: Cow Horn okra at 5”/13 cm (others shorter), green beans a bit thinner than a pencil, carrots at whatever size you like, 7”/18 cm asparagus, 6”/15 cm zucchini
Color: Garden Peach tomatoes with a pink flush. The “ground spot” of a watermelon turns from greenish white to buttery yellow at maturity, and the curly tendrils where the stem meets the melon to turn brown and dry. For market you may harvest “fruit” crops a bit under-ripe
Shape: cucumbers that are rounded out, not triangular in cross-section, but not blimps. Sugar Ann snap peas get completely round before they reach peak sweetness.
Softness or texture: eggplants that “bounce back” when lightly squeezed, snap beans that are crisp with pliable tips. Harvest most muskmelons when the stem separates easily from the fruit (“Full slip”).
Skin toughness: storage potatoes when the skins don’t rub off, usually two weeks after the tops die, whether naturally or because of mowing.
Sound: watermelons sound like your chest not your head or your belly when thumped. Try the “Scrunch Test” – press down firmly on the melon and listen and feel for the separation of the ripe flesh inside the melon.
Cabbages are fully mature when the head is firm and the outer leaf on the head is curling back. Ignore the separate “wrapper leaves” when making this judgment. If you need to keep mature cabbage in the ground a few days longer, twist the heads to break off some of the feeder roots and limit water uptake, and they will be less likely to split.
Select blue-green broccoli heads and harvest them before the flower buds open, but after they’ve enlarged. We press down with finger-tips and spread our fingers to see if the head is starting to loosen.
Sweet corn will be ready to harvest about three weeks after the first silks appear. Corn is ready when the ears fill to the end with kernels and the silks become brown and dry. An opaque, milky juice will seep out of punctured kernels. You can use your thumbnails to cur through the husk on the side and view the kernels. Don’t make your cut on top of the ear, or the dew and rain will get in and rot the corn.
Garlic is ready to harvest when the sixth leaf down is starting to brown on 50% of the crop. See Ron Engeland’s Growing Great Garlic. Harvesting too early means smaller bulbs (harvesting way too early means an undifferentiated bulb and lots of wrappers that then shrivel up). Harvesting too late means the bulbs may “shatter” or have an exploded look, and not store well.
Cut across hardneck garlic – airspaces around the stem show maturity
Wait until the tops fall over to harvest, then gently dig up the whole plant and dry. Leave the dry, papery outer skin on the onion for protection.
Four Ranges of Cold-Hardy Crops for Harvest at Various Stages of Winter
Crops to keep alive into winter to 22°-15°F (-6°C to -9°C), then harvest. Harvest and use soon: Asian greens, broccoli, cabbage, chard, lettuce, radishes. Harvest and store: beets, cabbage, carrots, celeriac, kohlrabi, winter radish (including daikon), rutabagas, turnips. Many greens and roots can survive some freezing, so it is worth experimenting to find how late you can keep crops outdoors.
Hardy winter-harvest crops: cabbage (Deadon), carrots, collards, kale, leeks, parsnips, scallions, spinach. We grow our winter-harvest crops in our raised bed area, which is more accessible in winter and more suited to small quantities.
Overwinter crops for spring harvests before the main season. Some crops, if kept alive through the winter, will start to grow again with the least hint of spring weather and be harvestable earlier than spring plantings. Depending on your climate, the list can include carrots, chard, chicories such as radicchio and sugarloaf, chives, collards, garlic, garlic scallions, kale, lettuce, multiplier onions (potato onions), scallions, spinach. In mild areas, peas can be fall sown for a spring crop. Sow 1″ (2.5 cm) apart to allow for extra losses.
Winter hoophouse crops: The rate of growth of cold-weather crops is much faster inside a hoophouse than outdoors. The crop quality, especially with leafy greens, is superb. Plants can tolerate lower temperatures than outdoors; they have warmer soil around their roots, and the pleasant daytime conditions in which to recover. Salad greens in a hoophouse can survive nights with outdoor lows of 14°F (–10°C) without inner rowcover.
In my post Root Crops in October, I gave this list of storable crops in the order for harvesting, related to how cold they can survive.
Clear and store (in this order):
Sweet potatoes 50°F (10°C)
“White” Peruvian potatoes 32°F (0°C) approximately
Celeriac 20°F (°C)
Turnips 20°F (°C)
Winter radish 20°F (°C)
Beets 15-20°F (°C)
Kohlrabi, 15°F (°C)
Carrots 12° F (°C)
Parsnips 0°F (°C)
Here are some links to a couple of good sources for more harvest information:
Prepare your garden for colder weather, plant winter crops where there is still time, harvest crops that will suffer from cold, construct low tunnels with rowcover or clear plastic to keep crops somewhat protected from wind and cold temperatures
I have written articles for Growing for Market magazine about growing and saving seeds (August and September issues), and planting garlic (October issue).
Given the shortages of some varieties this spring, it wouldn’t surprise us if more people tried producing seeds of vegetable or flower varieties this year. Here are links to articles from the August and September magazines, covering wet and dry seed processing.
Wet seed processing and saving
Wet seeds are embedded in fruit. Wet processing has four steps: scooping out the seeds or mashing the fruit, fermenting the seed pulp for several days, washing the seeds and removing the pulp and then drying the washed seeds.
Dry seeds develop in pods, husks or ears, and dry on the plant rather than inside a fruit. While you obviously want to get seeds into the hands of growers before they need to plant, and into seed catalogs before they get printed, often there is no urgency to extract the dry-seeded crops from their pods. You can wait for a slower time, or use seed cleaning as a rainy-day job.
Unlike white potatoes, which have the annual plant sequence of vegetative growth, flowering and dying back, sweet potato plants would go on growing forever if the weather remained warm enough. Choose when to dig them up, ahead of cold weather. The longer you wait, the bigger the potatoes, but you are gambling with the weather. Usually sweet potatoes are harvested in the week that the first frost typically occurs in your region. I have written plenty already in previous years about harvesting, so I won’t go into it here. See one of the links to those posts, or my slideshow, if you want to know what comes next, or your climate is considerably colder than mine in central Virginia.
Today I looked to see the “plenty” I had written in previous years, and was surprised not to find much! Every mid-October from 2012 to 2016, I mentioned sweet potato harvest, but many times it has been in passing, and mostly yield statistics (bragging or groaning). 2012 has the most detail on doing the harvest – read it below.
In 2019 we got a very nice yield and carried on eating sweet potatoes into September. Previously people seemed to lose interest in sweet potatoes in late May, and we would distribute our surplus to other people. This year we just kept eating and enjoying them. I can report that they did get wrinkly and grow big sprouts, but were still very tasty down to the last one in late September.
We now use electric fencing to keep the deer out, and grow on biodegradable plastic mulch to keep the weeds down, and use drip irrigation to grow the sweet potatoes up. These developments in our method became necessary over the years.
Yesterday we ate sweet potato leaves as a seasonal green. You can eat these throughout the growing season, but we usually don’t, as we hesitate to take away anything that is helping the tubers grow. But at harvest time, the leaves are about to return to the soil, so we clipped the vine tips and cooked them up. OK, interesting, never going to be a favorite for me, but perfectly acceptable, and less distracting than going off to harvest somehting else to eat in the middle of the big sweet potato harvest!
10/11/16: Yesterday we started harvesting our sweet potatoes. Yields look OK but not fantastic. We had a lot of problems with deer eating our sweet potatoes this year. We did have a temporary electric fence, but we often didn’t pay it good attention and it grounded out. Next year the rotation brings the sweet potatoes to a more traveled location. I can’t believe I’m already doing that “Gardener Survival Strategy” of thinking “Next Year Everything Will Be Perfect”!!
10/18/16: Our average first frost date is October 14. Actually from our own records it has averaged 10/22 over the last 11 years. . . . It’s good to be prepared.
10/20/15: We got our sweet potatoes all dug and safely indoors before Saturday night’s 27F and Sunday night’s 26F. Whew! Another Garden Year Milestone passed. We got about 223 boxes this year. The boxes contain about 23lbs each, so that’s 5129 lbs, plenty to feed 100 hungry people for six or seven months. . . . Our average harvest for this size patch (about 700 plants) is 4035lbs. This year we got a yield of a little over 7lbs of sweet potatoes per plant. Last year’s record crop was 11lbs per plant.
10/13/15: We are on the point of harvesting our sweet potatoes. After all the rain we had recently, we were waiting for the soil to dry enough to walk on. . . . I was worried for a couple of days that the weather would stay cold and the sweet potatoes might rot in the cold wet soil. One year when I was fairly new to Virginia I caused us to leave the sweet potatoes in the ground till early November (hoping they would grow a bit more) and then it rained hard and we ended up with a load of sweet potatoes that either rotted directly or else went through a transition to a hard uncookable state. I learned the hard way to harvest sweet potatoes before soil drops to 55F. This week I studied the soil thermometer and the max and min thermometer and was reassured by the warm sunny days. The soil has been drying out nicely. Tomorrow we start digging. It usually takes us three afternoons. Everything looks auspicious. No rain or horribly cold weather, enough people. . .
10/14/14: Our sweet potato harvest is huge this year! We mostly managed to keep the deer out of the plot, by luck and a scarecrow and things that fluttered in the breeze. We’ve filled all our usual boxes and then scrambled twice to find more! . . . . I counted the equivalent of 273 normal-sized boxes in the basement this morning. At 23 pounds for our standard box, that’s about 6280 pounds. We might be up to 6500 pounds by the time we’re done. This will be our record! I think our local food pantry will be getting some sweet potatoes this winter and next spring!
I compared sweet potato yields for different years. We usually have about 600 plants in 800 row feet (16″ spacing). Yield is about 11 pounds/sweet potato plant this year. But as they say “your results may vary.” Ours certainly have. Working back from 2012, we harvested 4070 lbs, 2208 lbs, 1860 lbs, “lots” (poor record-keeping!), 5590 lbs, 3820 lbs and 4050 lbs in 2007.
10/13/13, Sweet potatoes, statistics and inspiration: After a week of drizzle, it finally eased up and we started harvesting our sweet potatoes. . . . As usual, we set the dug roots in clusters, so we could see which plants yielded most and chose medium-sized roots from those to grow our slips next year. . . . This year, the Georgia Jet seem more productive than the Beauregard – I think that’s usual. We dug about a third of the crop the first day and got 86 boxes. The second day we had a lot of other harvesting (beans and broccoli being the most time-consuming), so we only dug another 36 boxes. . . .
Well . . . the yield dropped off a lot where the deer had been browsing (memo: fence out the deer in future!) We got a total of 177 boxes of various sizes, perhaps about 3939 pounds, almost two tons. . . .
Our yearly harvest of sweet potatoes has varied a lot, from 31 boxes (a sad year) to 243 in 2009. An average over ten years of 112 boxes, each weighing perhaps 23 pounds. . . . We always hope to have enough to last till the beginning of May, when people start to lose interest in sweet potatoes, and start hoping for tomatoes.
10/12/12: Usually sweet potatoes are harvested the week the first frost typically occurs. . . . Contrary to myth, there is no toxin that moves from frozen leaves down into the roots. On the other hand, cold injury can ruin the crop, and roots without leaf cover are exposed to cold air temperatures, and have lost their method of pulling water up out of the soil. Cold wet soil can quickly rot sweet potatoes (I know, it’s happened here).
To harvest, we first remove the vines from the area to be harvested that day. There is usually 3 afternoons’ digging for ours, and we want to leave live vines to protect the rest of the crop overnight. We use pruners to snip the vines where they emerge from the soil, leaving stumps to show where to dig. We roll the vines into the spaces between the rows.
Using digging forks, we carefully dig up the roots, which grow in the ground in a bunch-of-bananas shape. We want to select good potatoes for seed, and we grow several different kinds (Georgia Jet, Beauregard, and a couple of heritage varieties whose names we don’t know), so we make sure not to mix potatoes from different rows. As we dig, we set the potatoes out beside the spot where they’ve grown, one clump per plant, so it’s easy to identify the most productive plants.
It’s important not to bruise the roots, or to leave them exposed to temperatures higher than 90°F (32°C) for more than half an hour, or they will get sun-scald. Below 55°F (13°C), they’ll get chilling injury. We also avoid any abrasion of the skin, which is very fragile at this stage. We leave the sweet potatoes to dry on the ground for 1-2 hours, unless the weather is unsuitable. This year we had ideal weather, not too hot, not too cold, breezy enough to dry the skins, sunny.
We want to grow our own slips (baby plants) next year, so we save at least 1 root per 5 slips wanted. (1 good slip every 16″.) So to plant 800 row feet, (600 slips), we save 100 each of our two main varieties and 20 each of the two heirlooms. That should be plenty. Some will shrivel or rot, so we allow a margin. We don’t save for seed any roots that look diseased. We choose plants with a high yield and no string (rat-tail) roots. From these plants, we choose small-medium sized potatoes with typical shape and color.
When grading and crating the roots in the field, we first choose the seed potatoes, and then sort storable from “Use First” roots. Large open broken surfaces will cure and can be stored, but any roots with soft wet damaged areas or deep holes (whether from voles, bugs or fork tines) will not store, and should be graded out, for composting or immediate use. We sort into 4″ deep wood flats or 5″ plastic crates for curing, and buckets for the “Use First” category.
Immediately after harvest, we take the boxes of sweet potatoes into a warm damp basement below the dining hall, to cure. This allows the skin to thicken, cuts to heal over and some of the starches to convert to sugars. Uncured “green” sweet potatoes are not very sweet at all, and are better used in dishes where they combine with other foods. A baked uncured sweet potato is a sad disappointment.
We stack our boxes of roots on pallets, and put wooden spacer sticks between boxes in each stack, to ensure airflow. We get quite good temperatures, but keeping humidity up is difficult for us. We cover the flats with newspaper to hold in some moisture. The best result seems to come from splashing water on the concrete floor several times each day. We use box fans to improve the airflow, and the basement already has some natural ventilation.
Ideal conditions for curing are 85-90°F (29-32°C), and 80-95% humidity for 4-7 days, with some airflow and ventilation. Curing takes longer if conditions are less than perfect. The length of the curing period also varies with the dryness of the soil just prior to harvest. We usually reckon on 10-14 days. . . . .
So – how did we do this year? Middle of the road, I’d say. Decent yields, but not a bumper crop – we still had empty boxes left over. The deer were regularly eating our vines until quite recently. Last year we had a dog to chase the deer off, but he met with a road accident. His replacement was old, and she just wanted to be a pet, so we had deer again. We used drip irrigation and biodegradable plastic mulch this year, and did a good job of weeding, so I put the lower yields down to deer damage.
Root Crops to Plant in Central Virginia in October
We have now passed our last chances to sow root crops outdoors. But the exciting season in the hoophouse has just begun. In early October, we sow radishes in our hoophouse. See Root Crops in September for more about our succession of hoophouse radish sowing dates. We like Easter Egg (a multi-colored mix of red, plum, pink, purple and white varieties, that matures over several weeks), Cherry Belle, the fast, uniform red globes, and White Icicle, like baby daikon about 3” (7 cm) long. These three varieties all stay crunchy and tender. We have a dread of fibrous radishes! Most years we make a sowing at the beginning of October and another at the end, and these will feed us from early November until early February. The late October sowing lasts for 8 weeks, so it’s good to make sure we plant enough. Radishes do a lot to brighten up meals in December and January!
In mid-October (10/10-10/25), we sow our first of three plantings of hoophouse turnips. We like the very fast-growing and tender Hakureihybrid. It has short hairless tops which also make good eating. We sow this variety on the south side of the bed, leaving the other 3 rows for the taller varieties. We also like Early White Eggand Oasis, which are not quite as uniform as Hakurei, but are OPs and the seed is much cheaper. They produce more greens, which we value too. In the north row we often grow Red Round, a beautiful red-skinned turnip with tall attractive leaves. We also like Scarlet Ohno Revival, which has the advantage of hairless leaves. This is an Open Source Seed Initiative variety. The OSSI pledge: “You have the freedom to use these OSSI-Pledged seeds in any way you choose. In return, you pledge not to restrict others’ use of these seeds or their derivatives by patents or other means, and to include this pledge with any transfer of these seeds or their derivatives.”.
We thin the turnips as needed. If we sowed thickly, the first thinnings become baby greens for salad. Once the turnips are the size of marbles, we like to thin the plants to 3” (7 cm) apart and cook them whole, roots and greens together. The next thinning is to 6” (15 cm) and from that point on, we harvest the greens and roots separately. We get a ratio of one bucket of roots to two buckets of greens, which fits our needs perfectly. We like to mix the roots, as the one quarter of red roots adds a pop to the appearance.
Root Crops to Harvest in Central Virginia in October
We can continue harvesting beets (and beet greens), carrots, horseradish, kohlrabi, radishes, turnips (and turnip greens), and winter radishes outdoors. Once we have had a decisive frost we can harvest parsnips – the frost really improves the flavor. Our 9/6 sowing of hoophouse radishes will start to mature.
We tackle our process of clearing root crops and storing them, starting with celeriac (if we grew it this year). We start with the least cold tolerant roots and work our way to the most cold tolerant. This list is root crops only. See my list of Winter-Kill Temperatures of Cold-Hardy Winter Vegetables 2020 for a more complete picture of “Harvesting in Time”
Clear and store (in this order):
Sweet potatoes 50°F (10°C)
“White” Peruvian potatoes 32°F (0°C) approximately
Celeriac 20°F (°C)
Turnips 20°F (°C)
Winter radish 20°F (°C)
Beets 15-20°F (°C)
Kohlrabi, 15°F (°C)
Carrots 12° F (°C)
Parsnips 0°F (°C)
Wash, and store roots in perforated plastic bags in refrigerator or root cellar. We use a special measuring bucket lid to help new workers determine if roots are big enough to store.
Harvest sweet potatoes before soil temperatures go much below 55°F (13°C), or night air goes below 50°F (10°C). See the Special Topic below.
Harvest white potatoes when the skins have thickened. (When the skin is undamaged after rubbing two together. About 2 weeks after the tops die). See Harvesting Potatoes and Root Crops in June. Two or three days before harvesting, we spend the day removing the hay mulch from our 1600 row feet (488 m) potato patch to the compost area. Our potato digging machine can’t deal with mulch or heavy weeds. To fit with using machinery, we clear complete rows. We have a Perfect Potato Harvest Checklist. For fall harvesting we do the tractor work in the morning and pick up the potatoes in the afternoon, avoiding leaving any out overnight if it will be frosty. (When harvesting the March-planted potatoes in July, we do the tractor work early in the morning and start picking up the potatoes as soon as possible. We aim not to be outdoors after lunch when it’s hot, but if we need to, we will, as we don’t want ready-baked potatoes sitting on the soil!) Tractor time is 4 hrs x 2 people. Picking time is 30 people-hours.
For beets, we allow 6 people-hours per bed (360 row feet (110 m), and expect 2-3 50-pound (23 k) bags per bed. Cut the stems about ¼” (6 mm) above the root, to reduce “bleeding” when you cook the beets. I was reminded recently that not everyone knows that the easiest way to cook beets is to scrub them, boil them in the skins, drain and immerse in cold water, then simply slide the skins off. Hardly any wasted food and no wasted time.
For carrots, we allow 4.5-6.5 people-hours per (large) garden cart for washing, trimming and sorting. Plan to keep the last 15 minutes for clean-up. Divide the rest of the time available by 3. Use 1/3 of the time for digging, 2/3 of the time for washing and sorting. Add time to take to storage. Record yields. We take the carrot tops back and spread them across the beds. (fall harvest only ). In the spring and summer we take carrot tops to the compost pile, as the smell can attract carrot rust root flies. In late fall it is too late to sow cover crops to protect the soil, and the flies have gone to overwinter wherever they do that, so we spread the tops over the beds to provide some protection for the soil.)
Special Root Crop Topic for October in Central Virginia:
Harvest sweet potatoes
Here’s our method:
First roll up the drip tape. Harvest on 3 mild days – generally in the week that your first frost usually occurs (10/7-14). We expect our whole harvest of 800 row feet (244 m) to take 80 people hours. Allow 1/3 of the time for snipping, 1/3 for digging, 1/3 for crating and schlepping. Digging takes a bit less time than either of the other jobs. Even a few hours exposed to temperatures below 50°F (10°C) will cause chilling injury. (Frost on the leaves does not of itself damage the roots). Don’t leave clipped plants uncovered overnight. Don’t leave sweet potatoes outdoors. Clip the vines, dig carefully, set the tubers in plant-clusters to dry on the soil. Select seed tubers (healthy med-size tubers from high-yielding plants, no rat-tails). We save a generous 100 Georgia Jet, 100 Beauregard, 20 each of Bill Shane’s White and Jubilee. (These last two are unofficial names for varieties we were given and are maintaining for genetic diversity.)
Other Root Crop Tasks in Central Virginia in October:
Curing sweet potatoes and white potatoes
Cure sweet potatoes in collapsible, stackable holey crates (or in wooden flats with spacers for ventilation) and cover with newspaper on top, in a basement with the heater on, for 10-14 days (85-90°F, 27-32°C, 80-90% humidity) or longer if it’s cooler and drier. Use fans. Splash water on floor. Curing is complete when the skin is undamaged after rubbing two together. Restack the boxes (in a rodent-proof storage cage, if you are using an outbuilding).
Cure freshly harvested white potatoes in a root cellar at 60-75°F (15.5-24°C) for 2 weeks, with good ventilation, then cool cellar to lower temperature. See Special Topic for July. For weeks 2-4, the temperature goal is 50°F (10°C), and fresh air is needed about once a week. Our method of providing an air change in our cellar or adjusting the temperature is to leave the door open when the temperature will be closer to our goal than the current reality. It works well enough.
Day 5 – Saturday January 11 (Viñales) late afternoon
After lunch at Finca Paraiso restaurant and a tour of their beautiful farm, we visited
Finca L’Armonia (Ecological Permaculture Farm)
Our 27-year-old host farmer Yoani arrived on horseback. He is farming 1 hectare (2.2 acres) of his family of origin’s 13 hectares. It is a lovely farm. The farmer had twice been to France for permaculture training. His mother, sister, and grandfather farm the other 12 hectares as a coop that sells to the government (we saw part of this in a fenced area of shaded annual crops). He does permaculture on his portion.
He grows two varieties of coffee (trees his grandfather planted) and had coffee for sale in plastic water bottles. Because tourists are urged to drink only bottled water, empty water bottles are a convenient container for any kinds of seeds, as we saw at the bean seed conservation center, Finca Hoyo Bonito (see March 17 2020 post). He also grows passionfruit, avocado, pineapples, mangoes, and other fruit trees including Cuban pears.
He maintains worm bins and a composting toilet (top quality!) – the first composting toilet we saw on our tour. I am surprised there are not more composting toilets in the rural areas. Some tourist spots have horrible restrooms!
My room-mate Julia and I had dinner at our casa, cooked by our hosts. We had soup, salad, rice, red snapper fish, ice cream with honey. All delicious.
In the evening I did some shopping at a souvenir street market in Viñales.
Here is a video about this farm, from Franny’s Farmacy. Made by two of my fellow travelers on the OGS Tour.
To read more about the Organic Growers School organized trips and Cuban agriculture, see this article written by our fantastic tour guide Yoseti Herrera Guitián, who started working as a tour guide in 2013 with Amistur Cuba, a specialized tourism travel agency that is part of ICAP (Cuban Institute of Friendship with the Peoples). She has worked with diverse groups focused on topics such as health, education, culture and mostly agriculture. Open as a new page here: https://organicgrowersschool.org/cuba-through-the-seasons
Book Review: Soil Science for Gardeners, by Robert Pavlis, New Society Publishers, 2020. 228 pages, with charts and diagrams, $18.99.
I recommend this book to all gardeners who have hesitated to open a soil science text for fear of dry incomprehensible overloads of numbers. Robert Pavlis explains how your garden grows, and dashes cold water on false myths that may have been wasting your time and limiting your success for years! He leads us to a better understanding, including on a microscopic level, of soil biology, chemistry, physics, geology and ecology and to a place of wonder and curiosity at the everyday functioning of crops and soils.
This new comprehension can lead us to do right by our plants and our gardens, leading to healthier plants and higher yields. Robert writes in plain language, as a gardener with over 45 years of experience. He is the author of those Garden Myths books you might have seen. Perhaps, like me, you paid them little attention, thinking your own knowledge was fact-based. Even so, like me, you might find you had been holding onto some anti-facts (mine was that I believed compost is acidic – not so!). This book aims to have us understand real soil and make real improvements, via a Soil Health Action Plan at the end of the book.
The three sections of the book are Understanding Soil, Solving Soil Problems, and A Personalized Plan for Healthy Soil. A satisfying, logical sequence. Read the sections in the order presented! Robert says it’s very easy to grow plants if you understand the soil which anchors them, feeds them and provides the air and water they need to survive. With a solid understanding of what’s going on, you won’t need to memorize rules.
The 2016 definition of soil, by the Soil Science Academy of America is “Soil is the top layer of the Earth’s surface that generally consists of loose rock and mineral particles mixed with dead organic matter.” A rather bland underselling of what soil accomplishes. Here comes myth-bust #1: “Soil is not alive. It does not need to eat or breathe.” “The whole idea that soil is a living organism that requires similar attention to animals is completely false and leads to many poor recommendations for managing soil.” No, don’t give up here! It’s not the soil but the ecosystem of the soil and all the living organisms in and on it that holds the life. The ecosystem contains life, but is not itself alive.
Air and water are critical for good plant growth, about 25% of each. A simple, startling truth. The sand, silt and clay we might worry about make up another 45%, and 5% organic matter might fill out the total. A large tree can remove up to 100 gallons (400 liters) of water a day, discharging most of it into the air as water vapor. As the water leaves the soil, air is pulled in to fill the spaces. Roots pull the oxygen in, day and night, to convert sugars into energy. Were you also lead to believe that plants photosynthesized by day and respired only by night?
Did you know (I hadn’t thought about it) that “soil pH” is really an average of the pH of the water in the soil, and a spot with organic matter and lots of bacterial activity will have a very different pH from a spot with less organic matter? The rhizosphere (the area right around a plant’s roots) can have a very different pH from the soil solution further away. Plants can grow in alkaline soil because their roots are actually growing in acidic conditions. The nitrogen-fixing bacteria on legume roots cause the plant to release hydrogen ions, making the rhizosphere more acidic. To some extent, our efforts to change the soil pH can be undone by our crops and weeds! A soil property called buffer capacity lets the soil absorb materials at different pH and maintain its same level. Peat moss is acidic, but it does not acidify alkaline soil. The soil in the rhizosphere can be 2 pH units different from the soil around. This is usually written about in rather magical terms, but here it is in plain language.
Roots grow just fine where there is enough phosphorus. Adding more at transplanting doesn’t help, and can hinder. Visual plant symptoms can predict possible deficiencies, but are not a reliable diagnosis. Purple leaves may indicate phosphorus deficiency or cold temperatures, high light intensity, pest damage or lack of water. Or a nitrogen shortage reducing the plant’s ability to absorb phosphorus. There’s much that we don’t know!
Pay attention to the Cation Exchange Capacity – the measure of the soil’s ability to hold cations – because many plant nutrients are cations. You can increase the CEC by increasing the clay content, increasing the OM or increasing the pH. Read more in this book.
Have you ever thought about the “free” nitrogen from legume root nodules? Rethink of it as “homegrown” or “solar” rather than simply magic and free, because the leguminous plant may use up to 20% of the sugars produced during photosynthesis, to feed the bacteria.
Don’t justify your adherence to organic gardening by falsely claiming that synthetic fertilizers kill bacteria. Bacteria feed on both synthetic and organic fertilizers. This book challenges us to find the factual basis for choosing to grow organically, making us stronger advocates.
The bacteria chapter is followed by a chapter on fungi. Fungal spores are everywhere, even the Antarctic. Fungi are crucial for cleaning up plant litter on the soil surface. They grow above-ground hyphae which can penetrate dry leaves or wood chips and move the nutrients deep into the soil. Bacteria can’t tackle such tough stuff! 150 species of fungi capture and digest nematodes.
Why is organic matter important? This chapter explores the chemical and biological effects of organic matter on soil. Soil contains three forms of organic carbon: the living (15%), the dead and the very dead (stable humus and charcoal). Increasing the level of organic matter in the soil can increase aggregation, improve water infiltration (reducing runoff), increase aeration, increase water-holding capacity, improve tilth of clay soils, reduce crusting, and improve the size and distribution of the pore spaces. Those are just the physical effects. It will also increase the cation exchange capacity, increase the availability of nitrogen, boron, molybdenum, phosphorus and sulfur, and increase the microbial activity and diversity.
Often we think about adding partially decomposed OM such as compost and manure. We should face the reality that compost tends to have low levels of nutrients (maybe 1:1:1). The big value of these is in providing food for microbes, short-lived beings that provide a constant supply of fresh OM, multiplying its value. Partially decomposed compost takes about five years to finish decomposing, during which time it slowly releases nutrients. This gradual steady supply is what crops need. The humus left at the end is a complex molecular mixture of carbon, hydrogen and oxygen, resistant to further decay.
The initial effect of adding fresh OM (not composted OM) is an explosion of microbial reproduction, feeding and death. The microbes use nitrogen, which can cause plants to suffer a shortage. It takes time for a new balance to be achieved, providing adequate N for the plants. The needs for the N can encourage gardeners to add so much compost that the P level is too high, which can bring death to mycorrhizal fungi, leading to roots driving deeper to access their own P from the soil directly. We have very high soil P, a result of misunderstanding soil test limits. I have worried about it, then read more and stopped worrying. Soil P is pretty stable. If you are not leaching P into a waterway, it just stays in your soil until a plant need it. We switched to using less compost and more cover crops where we could. We were already using a lot of cover crops – it’s not like we were slouches in that department! After more time, I settled on accepting our situation, and as the plants show no sign of P-caused problems and our soil is bursting with earthworms, it doesn’t affect us much.
I mentioned at the beginning that I learned that finished compost is alkaline, not acidic. In the initial composting stage, acidity happens. Then fungi thrive, and decompose the tough lignin and cellulose, causing the pH to rise and bacteria to take over. Compost-making has lots of myths! Poorly understood science makes them grow, I suppose. Bokashi composting, for example (more of a fermentation than a composting process) is based on the idea that fermented material decomposes faster, although it’s unclear if this is really true. “The best method of composting is the one that you do and continue to do because you like doing it. Any form of composting is better than taking yard waste to the curb.”
The Rhizosphere chapter is fascinating! Root exudates can restrict the growth of competing roots, attract microbes into symbiotic relationships, Change the chemical and physical properties of the soil solution and the soil, and make nutrients more available. Bacteria make explosive population growth as they feed on exudates. Then their predators, nematodes and protozoa, join the party. The soil water around the roots becomes a nutrient soup. By photosynthesis, the plants produce the attractive exudates that the soil food web turns into plant nutrients right where the roots can efficiently hoover them up. Plants are active in seeking nutrients, not passive recipients. Not to say they have knowledge, or think and plan. It’s a matter of chemical reactions controlled by enzymes with the capacity to change their activity based on the presence or absence of chemical triggers. Let’s marvel at the reality! We don’t need fairy stories!
The second section of the book, Solving Soil Problems, starts with identifying the problems, and works through techniques affecting the soil, chemical and microbe issues, increasing organic matter and structural problems. We are not feeding plants, we are replacing missing nutrients in the soil, so they can take the nutrients they need. The solution will depend on your soil, so a “tomato fertilizer” is not going to be what tomatoes need in every soil. If you plan to top up the missing nutrients, get a soil test to learn what those are. But if you plan to apply manure or compost everywhere as your only amendment, your money is wasted on a soil test. If you add compost every year and return cover crops, organic mulch and your plant debris to the soil, and your plants are mostly growing well, you probably don’t need to add any other fertilizer to your garden. This alarmed me a bit. What about boron shortage, which happens here? Yes, if you are a farmer or market gardener, yields do matter and soil tests (free for commercial growers in Virginia) will be worthwhile. But for a home gardener, or a landscape gardener, yields might not be at the top of your list. Robert explains various tests, and gives his take on how useful they are. The information here can save a lot of confusion and wasted effort.
In the techniques chapter, the author explains the dramatic difference in available nitrogen in a cultivated garden and a no-till one. No-till can supply up to five times the nitrogen, because tilling adds more air into the soil, increasing the microbial activity, burning up the OM. There is a useful chart comparing the effects of fertilizer, compost and wood chips on the soil. We’ve all learned not to bury wood chips in the soil, where they use up the nitrogen while decomposing. But on the surface they can do wonders.
Crop rotation has come under scorn recently from commercial growers who are focused on maximizing yield and profit for their time on small areas of land. Sure, salad mix and baby spinach can rake in the money. But generations of farmers have learned to grow different types of crops each year in a particular spot. This can increase yields 10-25%, even though we are not sure why. Studies have shown it’s not simply nutrient availability. It could be pH changes freeing up more nutrients, or microbe biodiversity, or differing root growth granting access to more depth than the current crop alone can achieve. Rotated crops are more drought resistant and make better use of nitrogen. Research is needed.
As I was happily digesting this book I was brought short by this mnemonic that still puzzles me: “If you have trouble remembering whether P stands for phosphorus or potassium, remember that these nutrients are listed in alphabetical order. Phosphorus comes before potassium in the alphabet, and so P comes before K.” Um, K comes before P, last time I looked. Confusing.
Does rock dust add nutrients? No evidence, says Robert. Do not be beguiled by mineral products claiming to add 74 minerals to your soil. Plants might only use 20 of them. More is not better! Beware fad products such as biostimulants and probiotics. Plants cannot use vitamin B1. What about compost tea? Yes, it adds nutrients, but claims that the included microbes work wonders are not supported by science: test results are very mixed, including worse. Sometimes we are too gullible! Milk, molasses: they add nutrients but no special magic. Fermenting something cannot add nutrients – it could make some more available, although that isn’t proven either. The fungal and bacterial populations increase, but are the species nutritious ones or pathogenic ones?
The gardener’s goal is to farm healthy microbes, even though they are too small to see. Use the state of the soil and the health of the plants as indicators of the health of the microbes. Supply OM, water and you’re on the right track. It has been proved useful to add rhizobium legume inoculant if you haven’t grown legumes for some years. Fungal inoculation of soybeans in low phosphorus soil will be effective. Not otherwise.
The author’s general practice is to improve the soil environment to help existing microbes. There is a list of 7 general ways to do that. There is a whole chapter on increasing OM, using what’s local and cheap. Coir is a waste product, but its production causes environmental damage to local water supplies (large amounts of sodium have to be leached out).
Biochar, one of the new “Garden Wonders”, has claims to make big improvements to the soil food web. Most of the biochar studies have been conducted in labs, not on farms. Even then, 50% of the studies report higher yields, 20% report no change, and 30% report a decrease. There are probably better ways to spend your money!
What about gypsum? I believed the common advice to use it to break up clay soils. Mostly this myth is not supported by evidence. Gypsum can have some negative effects. Add more OM instead. Likewise for improving sandy soils: add more OM.
The final section of the book is a set of worksheets and instructions to help gardeners improve the soil health where they are. This is a slow process, so start soon! Robert has also made the forms available on his website www.gardenfundamentals.com/soil-book-forms. First assess your soil, then make an action plan, then record your progress.
I recommend this book for all sustainable/regenerative/organic gardeners and small-scale farmers, and even large-scale farmers who realize there are gaps in their understanding of soil science. This book is very accessible, user-friendly and full of soil-based common sense. Winter is a good time to make new plans!