Winter-Kill Temperatures of Cold-Hardy Vegetables 2021

Winter-Kill Temperatures of Cold-Hardy Vegetables 2021

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 2020-2021 was mild, with our lowest temperature being a single late January night at 10°F (-12°C). We had one night at 11°F (-12°C) one at 17°F (-8°C), three at 18°F (-8°C also) and one at 19°F (-7°C). very little snow or ice. Similar to temperatures in the 2019-2020 winter.

The winter of 2018-2019 had lowest temperatures of 6°F (-14°C) in late January 2019, 8°F (-13°C) in December 2018 and a couple of 11°F (-12°C). In early January 2018, we had some extremely cold temperatures of -8°F and -9°F (-22°C and -23°C). Averaging our winter low over those four winters 2017-2021 gives 4.8°F (-15°C), within the zone 7a range.

Georgia Cabbage Collards, good down to 20F (-7C) Photo **Southern Exposure Seed Exchange**

New Info this winter

I’ve added in some temperatures for collard varieties (Georgia Cabbage collards, McCormack’s Green Glaze, variegated collards) from the Heirloom Collards Project, and also gained some info on spinach (Long Standing Bloomsdale), kales (Rainbow Mix Lacinato) and mustards (Chinese Thick-Stem) from Southern Exposure Seed Exchange. I’ve added in their suggestions on cold-tolerant early spring lettuces, Crawford, Simpson Elite, Susan’s Red Bibb and Swordleaf.

My results from other years still hold up.

Swordleaf lettuce on the right with another lettuce and radishes in spring.
Photo Bridget Aleshire

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. Crops get more damage when the weather switches suddenly from warm to cold. If the temperature drops 5 or more Fahrenheit degrees (about 3 C degrees) from recent temperatures, there can be cold damage. The weatherman in Raleigh, NC says it needs 3 hours at the critical temperature to do damage. Your own experience with your soils, microclimates and rain levels may lead you to use different temperatures in your crop planning.

Reflect spinach in the open got damaged but not killed at -9F.
Photo Pam Dawling

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)), some 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 collards (Georgia Cabbage Collards, variegated collards), 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).

Ruby chard, good down to 15°F (-9.5°C). hardier than Bright Lights, but less hardy than green chard varieties.
Photo Kathryn Simmons

15°F (-9.5°C): Some beets (Albina Verduna, Lutz Winterkeeper), beet leaves, some broccoli and cauliflower leaves, 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 Four Seasons, 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, some 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 10°F), Belle Isle upland cress, some endive (Perfect, President), young Bronze fennel, Blue Ridge kale, probably Komatsuna, some leeks (American Flag (Broad London), Jaune du Poiteau), some covered lettuce (Pirat, Red Salad Bowl, Salad Bowl, Sylvesta, Winter Marvel), Chinese Thick-Stem Mustard may survive down to 6°F (-14°C), 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.

Garlic shoots poking through the mulch in January. Survive down to 5°F (-15°C), and if killed, will regrow from underground.
Photo Pam Dawling

5°F (-15°C): Garlic tops even if small, some kale (Winterbor, Westland Winter), some leeks (Bulgarian Giant, 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 and the Ice-Bred White Egg turnip 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, McCormack’s Green Glaze), 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, Long Standing Bloomsdale, Olympia). Walla Walla onions sown in late summer are said to be hardy down to -10°F (-23°C), but I don’t trust below 0°F (-18°C)

Crimson clover is hardy down to 0°F (-18°C) or perhaps as cold as -10°F (-23°C)

-5°F (-19°C): Leaves of overwintering varieties of cauliflower, Vates kale survives although some leaves may be too damaged to use. Lacinato Rainbow Mix kale may survive this temperature.

A cover crop mix of winter rye, hairy vetch and crimson clover.
Credit Kathryn Simmons

-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).

Hoophouse Notes

Winter crops snug in our hoophouse in a December snowstorm.
Photo Pam Dawling

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 Notes

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, Oscarde, Outredgeous, Pirat, Red Cross, Red Sails, Red Salad Bowl, Red Tinged Winter, Revolution, Rouge d’Hiver, Salad Bowl, Sylvesta, Tango, Winter Marvel, Winter Wonderland.

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

Notes on Chicories and Endives

Verona Red radicchio, hardy to about 20°F (-7°C).
Photo **Southern Exposure Seed Exchange**

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.

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?

Go to my Events Page for more information on these online events

Mother Earth News Fair Online: Food Independence Course Part Two was released on 3/26/21.

It consists of eight video presentations, most of which come with pdf handouts. My contribution is Growing Asian Greens, and pairs nicely with Guide to Asian Vegetables with Wendy Kiang-Spray, author of The Chinese Kitchen Garden: Growing Techniques and Family Recipes from a Classic Cuisine. Other topics include Dandelion Wine, Homemade Teas, Food Conversations, Passive Solar Greenhouse Design, Productive Growing from Home, and Growing Your Own Spices.

You can subscribe to the All-Access Bundle for $2.99/month (or $35 for a year).

My previous contribution is an 8-part Garden Planning Course

I also did a workshop on Winter Cover Crops for Gardeners as part of the Winter Gardening Course.

All these and many more videos and handouts are available as part of the All-Access Bundle.

Root Crops in December

Root Crops to Plant in Central Virginia in December

A stormy winter day, garlic, rowcovered spinach beds and our hoophouse.
Photo Wren Vile

Reread Root Crops in October for more ideas of things you might plant, if you are in a much warmer climate zone than us. We are in winter-hardiness subzone Zone 7a, with an average minimum temperature of 0° to 5° F (-18°C to -15°C). We’re not planting anything outdoors in central Virginia in December. But in the hoophouse, we are sowing a couple of things.

Eliot Coleman has given the name Persephone Days to those with less than 10 hours of daylight, when little plant growth happens. Here in central Virginia, the Persephone Days last from November 21 to January 21. Further north, the period is longer, and it is necessary to grow more of what you want to eat in winter and keep it in a holding pattern to see you through to the other side of the Persephone Days. The holding pattern could be crops in storage, which I wrote about in Root Crops to Plant in Central Virginia in November. Or it could be crops in the ground in a hoophouse.

Temperature also contributes to rate of growth and this is where hoophouse crops score big! It can be a lot warmer during sunny days inside a hoophouse, and our double-plastic hoophouse keeps nighttime temperatures about 8F (4.5C) degrees warmer than outdoors, sometimes 10F (5.5C) degrees warmer. In addition, plants can tolerate lower temperatures inside a hoophouse. The soil stays warmer and the plants recover in the warmer daytime conditions (it seems to be the night+day average temperature that counts). We find, in practice, the period of slowest growth here is December 15 to February 15: still two months long, but lagging the shortest days by three weeks. It takes time for the soil to cool down in late fall and time for it to warm up in early spring.

Hoophouse radishes and Yukina Savoy in December.
Photo Wren Vile

In our double-layer hoophouse, plants without any inner rowcover can survive 14F (7.7C) degrees colder than they could survive outside; with thick rowcover (1.25oz Typar/Xavan) inner covers, 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). Turnips (and many cooking greens) survived a hoophouse temperature of 10.4°F (-12°C) without rowcover, -2.2°F (-19°C) with.

In early December, we sow turnips #3. We sow Hakurei, Early White Egg, Oasis, and Red Round. They will struggle a bit to grow, so they are only worth sowing if we thin them promptly and harvest them on the small size, as the plants will start bolting in early March. See Root Crops in October, for details of thinning and harvesting.

In late December, we sow hoophouse radishes #5, Easter Egg and White Icicle. Cherry Belle and Sparkler types grow too fibrous at this time of year. See Root Crops in September for more about our succession of hoophouse radish sowing dates. Unlike the late October sowing which lasts for 8 weeks, the November sowing will only be good for the (slow-growing) four weeks of February, and this late December one for four weeks from mid-February to mid-March. In this case, it is because the temperature in the hoophouse and the daylength will have increased by then and the radishes will grow fast and start bolting.

Young Red Round turnips in our hoophouse in late November.
Photo Pam Dawling

Root Crops to Harvest in Central Virginia in December

In central Virginia, there are normally no roots that we could be harvesting outdoors in December except parsnips. Jerusalem artichokes are hardy down to 0°F (-18°C), but we haven’t grown those in decades. Horseradish is similarly hardy, but not a mainstay of nutrition. The months with R in them are the horseradish harvest months. This is not woo-woo, it happens that September to April have R in them, and the summer months do not!

Horseradish regrowing up through the mulch in early spring.
Photo Kathryn Simmons

If temperatures have not yet dropped to 12°F/-11°C, we could dig Danvers carrots, Cylindra beets, and any rowcovered rutabagas (swedes). Albina Verduna, and Lutz Winterkeeper beets are hardy down to 15°F (-9.5°C), as are most kohlrabi and rowcovered turnips. But we don’t take that chance. We like to gather our root crops in and have them safely stored. We also like to put our feet up more in December!

Covered beets, covered winter radish are OK down to 10°F (-12°C).

In the hoophouse we can harvest radishes #2 until 12/25, #3 (sown October 30) from 12/15 to 2/1. We harvest our first turnips (sown around October 13) as thinnings from November 29 and by pulling out the biggest from December 5, until mid-February, by which time we can have made a start on the second sowing (October 25).

Turnips in our hoophouse in December.
Photo Wren Vile

See my list of Winter-Kill Temperatures of Cold-Hardy Winter Vegetables 2020 for a more complete picture of “Harvesting in Time”

Other Root Crop Tasks in Central Virginia in December

From storage we can eat (if we grew them!) beets, carrots, celeriac, kohlrabi, parsnips, potatoes, rutabagas, sweet potatoes, turnips. Stored crops need to be visited at least once a month and checked for decay.

In our winter squash cage we keep some pancake turners rejected by the kitchen crew. If a squash is having a meltdown, I slide it onto a tray or a bucket lid and throw it outside. The first time I did that this year, I made the mistake of sliding a second squash on top of the first on my bucket lid. The first one couldn’t support the weight of the second. Messy! Sliding them into a bucket would have been safer.

A fine winter squash medley (no, they’re not root crops!)
Photo Southern Exposure Seed Exchange

Special Root Crop Topic for December in Central Virginia

Crop Review and Planning Part One

This is a wider task, not restricted to root crops. In November we have a Crop Review, and then start to plan our crops for next year. We like to get our seed orders in early, to maximize our chances of getting the varieties and quantities we’d like. Some seeds might be in short supply this time, because of all the new gardeners and Covidsteaders that joined our ranks this year.

We consider how well our crops did in terms of plant vigor, disease-resistance, yield, quality, flavor and timing. Did they come in all at once? A benefit for storage crops or those you might sell wholesale. Not so great if you want an extended harvest period.

Planting dates, soil quality, sufficiency (or otherwise) of pest and weed control, plant protection from the elements are all factors that affect yield and crop quality. We can plan to make changes to those things next year. We can decide to plant a different amount, or spread out the planting dates. This can lead to a new calculation of how much seed to buy for the coming year.

By now the seed catalogs are starting to arrive and we can look at what varieties are on offer. Is there a faster-growing turnip? A different carrot we’d like to try? Something with more resistance to the disease we noticed this past year? Something more recommended for our climate or region? While you’re browsing, make a back-up plan if you can’t get your first choice, either from the same catalog, or another.

Hoophouse turnips and baby lettuce mix in December (note the low sun angles!)
Photo Wren Vile

Garden Planning, Winter Harvests and Speaking Events

‘Tis the season – after the relaxation of the holidays – time for garden planning. Inventory your seeds left from last year, peruse the catalogs and prepare your seed orders. The earlier you get them in, the more likely you are to get the varieties you want, before anything is sold out.

I notice that readers of my blog have been looking up the Twin Oaks Garden Calendar, also known as The Complete Twin Oaks Garden Task List Month-by-Month. You can search the category Garden Task List for the Month, or you can click on the linked name of the month you want. At the end you can click on “Bookmark the Permalink” if you might want to refer to this in future. Remember, we’re in central Virginia, winter-hardiness zone 7a. Adjust for your own climate.

Meanwhile, despite the turn to cold weather, we are not huddled indoors all the time. Each day, one or two of us sally forth to harvest enough vegetables to feed the hundred people here at Twin Oaks Community. Outdoors, in the raised bed area, we have winter leeks, Vates kale, spinach and senposai. We could have had collards but we lost the seeds during the sowing period, so we have lots of senposai instead. Senposai leaves (the core of the plant may survive 10F), are hardy down to about 12F. I noticed some got a bit droopy when we had a night at 15F. Collards are hardier – Morris Heading (the variety we grow) can survive at least one night at 10F.

Hoophouse December View
Photo Kathleen Slattery

In the hoophouse, we have many crops to choose from: lettuce, radishes, spinach, tatsoi, Yukina Savoy, Tokyo Bekana, turnips and turnip greens, scallions, mizuna, chard, Bull’s Blood beet greens.

Hoophouse scallions ready to harvest.
Photo Pam Dawling

Pak Choy and Chinese cabbage heads are filling out, ready for harvest in January.

Tokyo Bekana, a non-heading Asian green, has large tender leaves, which we are adding to salad mixes. It can be used as a cooking green, but only needs very light cooking. It will bolt soon, so we are harvesting that vigorously, not trying to save it for later.

The kale and senposai in the hoophouse are being saved for when their outdoor counterparts are inaccessible due to bad weather. The spinach is added to salad mixes, or harvested for cooking when outdoors is too unpleasant, or growth slows down too much.

Hoophouse winter lettuce: Green Forest and Red Salad Bowl, two of our fifteen varieties.
Photo Wren Vile

Another kind of planning I’m doing right now is scheduling my speaking events for the coming year and practicing my presentations. Last week I updated my Events page, and this week I’m adding a new event: The September 21-22 Heritage Harvest Festival.

I might pick up a couple of events in late April and early June, but that’s just speculation at this point.

Right now I need to practice for the CASA Future Harvest Conference January 11-13. Cold-hardy Winter Vegetables and a 10-minute “Lightning Session” on using graphs to plan succession plantings for continuous harvest. Click the link or my Events page for more on this.

Year Round Vegetable Production, speaking events

Year round vegetable production dawling 2017 90 mins from Pam Dawling

Here’s my newest slide show, Year Round Vegetable Production, which I presented at the Field School in Johnstown, TN on December 7. To view full screen, click the diagonal arrows at the bottom right, and to move to the next slide, click the triangle arrow pointing right.

The Field School is a Beginning Farmer program, under the Appalachian RC&D Council. The Field School organizes a monthly series of workshops (November 2017 through August 2018) that provides an overview of small-scale farming in East Tennessee’s mountains and valleys, taught by 20+ farmers and agricultural professionals. It is arranged by the Appalachian RC&D Council, Green Earth Connection, and many area partners with major support from USDA.

As well as my double presentation on Thursday evening, I attended a Q and A brunch on Friday morning and got the chance to meet the new (ish) farmers individually. It was a pleasure to meet such enthusiastic dedicated growers.

My other presentation on Thursday 12/7 was Crop Planning, which you can view by clicking the link.

The school session 2017-18 is already full even though they have expanded to have two tracks (Produce or Small Livestock) in this their third year. Go to their website if you are local and want to be on their waiting list if spots open up. They also sell tickets to the public for some of their workshops.

Beginning farmer training is available in most states, loosely under the USDA, but without a central organization. Do a web search for your state and “beginning farmer training” if you are looking for something like this. Or check out this list on Beginningfarmers.org.

I have been firming up several speaking events in the new year. Here some info on some of those (click the Events tab or the individual event links for for more details):

The Chesapeake Alliance for Sustainable Agriculture Future Harvest Conference January 11-13, 2018 at College Park, MD.

Ira Wallace (Southern Exposure Seed Exchange), Gabe Brown, Michael Twitty and Craig Beyrouty are giving the meal time addresses.

On Saturday January 13 11.30am -12.30pm I’m presenting

Cold-Hardy Winter Vegetables – Why farm in winter? Information includes tables of cold-hardiness; details of four ranges of cold-hardy crops; overwintering crops for spring harvests; scheduling; weather prediction and protection; hoophouse growing; and vegetable storage.

I am also participating with other speakers in a new format Lightning Session Round, 2.15-3.30pm on Saturday, where we each get 10 minutes to tell the audience the top 5 things we want them to know about a certain topic. I’m speaking on Six Steps to Using Graphs to Plan Succession Crops for Continuous Harvests

I will be signing books at the Southern Exposure Seed Exchange booth at points during the conference.

February 7-10, 2018 Pennsylvania Association for Sustainable Agriculture, Farming for the Future Conference, State College, PA https://www.pasafarming.org/events/conference. I’ll be presenting three workshops:

Storage Vegetables for Off-Season Sales Friday 12.50 – 2.10 pm

Grow crops you can sell during the winter, while allowing yourself some down-time and reprieve from outdoor work. Choose suitable crops, schedules and storage conditions. Understand your weather and basic crop protection. This workshop will provide tables of cold-hardiness and details of four ranges of cold-hardy crops (warm and cool weather crops to harvest and store before very cold weather; crops to keep alive in the ground further into winter, then store; hardy crops to store in the ground and harvest during the winter, and overwinter crops for early spring harvests before the main season). It includes tables of storage conditions needed for different vegetables and suggestions of suitable storage methods, with and without electricity.

Cover Crops for Vegetable Growers Saturday 8.30 – 9.50 am

Using cover crops to feed and improve the soil, smother weeds, and prevent soil erosion. Selecting cover crops to make use of opportunities year round: early spring, summer, fall and going into winter. Fitting cover crops into the schedule of vegetable production while maintaining a healthy crop rotation.

Fall and Winter Hoophouses Saturday Feb 10 12.50-2.10pm

How to grow varied and plentiful winter greens for cooking and salads; turnips, radishes and scallions. How to get continuous harvests and maximize use of this valuable space, including transplanting indoors from outdoors in the fall. The workshop includes tips to help minimize unhealthy levels of nitrates in cold weather with short days. Late winter uses can include growing bare-root transplants for planting outdoors in spring.

There will be handouts for each workshop and book signing

March 9-11 2018, Organic Growers School Spring Conference at UNC-Asheville, Asheville, NC. I’ll be presenting three workshops:

For the Gardener track: Growing Sweet Potatoes from Start to Finish

At this workshop you will learn how to grow your own sweet potato slips; plant them, grow healthy crops and harvest good yields, selecting suitable roots for growing next year’s slips. You will also learn how to cure and store roots for top quality and minimal losses. This workshop will be useful to beginners and experienced growers alike.

For the New Farmer Track: Cover Crops for Vegetable Growers

Sustainable Farming Practices

An introduction to year round vegetable production; crop planning and record-keeping; feeding the soil using crop rotations, cover crops, compost making and organic mulches; production tips on direct sowing and transplanting, crop spacing, succession crop scheduling to ensure continuous harvests, efficient production strategies, season extension, dealing with pests, diseases and weeds; determining crop maturity and harvest methods.

April 12, 2018, 9am to noon,

Louisa Master Gardener Group Tour of Twin Oaks Gardens

Cold nights, Cool season hoophouse crops, CASA conference

Ginkgo Golden Puddle Day
November 10 2017.
Photo Pam Dawling

We had a few 24F nights and the ginkgo trees responded by instantly dropping all their leaves. A beautiful sight.

At the Carolina Farm Stewardship Association Sustainable Agriculture Conference I gave a presentation called Sequential Planting of Cool Season Crops in High Tunnels as part of the Friday morning High Tunnel Crop Production Intensive workshop. It’s a new workshop I prepared especially for the CFSA. I usually call the structures hoophouses rather than high tunnels, but either name is fine. It used to be said that farmers called them hoophouses and researchers and academics called them high tunnels. Nowadays there is not such a binary distinction; farmers do research and teach, researchers and academics grow crops. Here is the longer version of the slideshow, including “bonus material” I didn’t include in the 60 minute presentation. Click the diagonal arrow icon to view full screen.

Sequential planting of cool season crops in high tunnels Dawling 2017 from Pam Dawling

On the Sunday I gave a presentation on Year-Round Hoophouse Production which was a back-to-back presentation of the Hoophouse in Spring and Summer and the Hoophouse in Fall and Winter. You can view those slideshows by clicking the links to them on the SlideShare.net site.

I’ve added a new event to my calendar for January. You can see all the events I plan to speak at, by clicking the Events tab at the top of the screen on my home page. This one is the Chesapeake Alliance for Sustainable Agriculture Future Harvest Conference January 11-13, 2018 at College Park, MD.

On Saturday January 13 11.30am -12.30pm I’m presenting Cold-Hardy Winter Vegetables – Why farm in winter? Information includes tables of cold-hardiness; details of four ranges of cold-hardy crops; overwintering crops for spring harvests; scheduling; weather prediction and protection; hoophouse growing; and vegetable storage.

I might also be participating with other speakers in a new format Lightning Session, where we each get 10 minutes to tell the audience the top 5 things we want them to know about a certain topic. That isn’t decided yet.

I also hope to be signing books at the Southern Exposure Seed Exchange booth at some point.

Meanwhile here on the farm it’s got colder, as I said at the beginning, and even dreary some days. We are getting our winter carrots harvested, getting ready to plant garlic, adding draft-proofing strips to our hoophouse doors, and admiring and harvesting our hoophouse salad crops.

November hoophouse lettuce bed.
Photo Wren Vile

Upcoming events, Growing for Market article, Organic Broadcaster

Harvesting Zephyr yellow squash.
Photo Brittany Lewis

Starting with what’s being harvested now – squash and zucchini are coming in nicely. The hoophouse Gentry yellow squash (chosen for being fast-maturing) is coming in by the bucketload, and the outdoor yellow squash and zucchini have started producing.

I’m off to Burlington, Vermont this weekend, for the Mother Earth News Fair. I’m giving two workshops:

Cold-hardy Winter Vegetables,on Saturday 6/10 at 11 am on the Yanmar Sustainability Stage, immediately followed by book-signing at the Mother Earth News Bookstore noon- 12.30.

Producing Asian Greens on Sunday 6/11 at 3.30 pm on the Heirloom Gardener Stage.

I’m also doing demonstrations of tomato string-weaving at the New Society Publishers booth 2611, near the Mother Earth News Stage (not the Bookstore this time), at 10 – 10.30 am and 3-3.30 pm on Saturday and 10 -10.30 am, 11- 11.30 am and 2- 2.30 pm on Sunday. Check out my Events page to see the pink sparkly tinsel tomato plant models I use!

At the Heritage Harvest Festival near Charlottesville, Virginia, on Friday September 8 (the Premium Workshops before the main Festival), I’m presenting on Growing Sweet Potatoes at 3.30-4.30 in classroom 7, followed by book-signing at the Monticello Bookshop.

The June/July summer issue of Growing for Market magazine is out, and includes my article on Hoophouse soil salt buildup. This is an issue we have been dealing with – we see white deposits on the soil. I did a lot of research and found ways to water the salts back down deep in the soil profile. I also gathered information on how to measure and monitor salinity, and how to understand the test results and their different testing methods and different units of measure. I learned about salt tolerance of different crops, the plant symptoms of excess salinity, and how to prevent the problem in future. This topic is rising in importance as more people use hoophouses with drip irrigation systems. We were blithely ignorant for our first several years of hoophopuse use, as salinity takes a few years to really develop, and there wasn’t much information available.

I’m also looking forward to reading the other articles, especially Summer lettuce lessons from Southern growers by Jesse Frost. There are some great photos of beds covered with hoops and shade-cloth, which show a good system. I always appreciate articles written for southern growers, which can be in short supply.

Daisy Fair in Utah’s zone 5 has written about moveable tunnels with in-ground hydronic heat. So there’s information for cold climates too. Sam Hitchcock Tilton has an article with tips learned from Dutch and Swiss farmers. Robert Hadad advises on careful monitoring of costs of production in order to actually make a living from farming. The flower growing article in this issue is from Debra Prinzing and is about American Flowers Week, a chance to highlight American-grown flowers with some light-hearted fun photos.

The May/June Organic Broadcaster just arrived in its paper format – I’ve had the digital one for a while. Good thing I’ve got that long car ride to Vermont this weekend to catch up on my farming reading!

The front page story this time is about Kansas farmers, Tim and Michael Raile, transitioning thousands of dryland (non-irrigated) acres to Organic steadily over the next 5 or 6 years. Dryland farming focuses on moisture retention. The Railes grow a wheat/corn/
sunflower/milo (grain sorghum)/fallow rotation. They are also trialing some ancient grains.

Organic production in the US is not meeting demand, and organic imports are increasing, including organic soy and feed corn, not just bananas and coffee. More farmers want to produce Organic poultry, eggs, milk and meat. And so they are looking for Organic feed at an affordable price. This is often imported, which raises issues about how Organic Standards vary from one country to another, and the bigger issue of sustainability – not always the same as Organic! Does it really make sense to ship in grains to feed livestock?

Harriet Behar writes about the true meaning of Organic and overall methods of production. It’s not just about following rules on allowed inputs and materials – it’s a whole approach to how we treat the soil, our plants and livestock.

Hannah Philips and Brad Heins share research on how cover crop choices can influence the fatty acids and meat of dairy steers. Jody Padgham writes about CSAs responding to competition and decreasing membership by offering more options on shares and delivery. Gone are the days of “One box, one day, one price” CSAs. Numerous modifications of the basic CSA model have sprung up to better fit the diverse needs of customers (members). Kristen McPhee writes about the Vermont Herb Growers Cooperative, which buys from various small-scale growers and aggregates orders to larger buyers. Other topics covered include lessons learned from Hawaii’s GMO controversy, paying for end-of-life care without losing your farm, and many short items and classified ads. As always, a newspaper packed with information.

And by the way, we’re also picking blueberries – ah! heaven!

Events List 2016

I’ve been busy planning my workshops for the next several months and beyond. Here’s a list of what I have confirmed and some that are just possibilities at this point. Remember, conference registrations can make nice gifts! (as can books – click my Book Reviews category in the side bar.)

Southern Sustainable Agriculture Working Group

Practical Tools and Solutions for Sustaining Family Farms conference, KY.

Dates: January 29-30, 2016 (pre-conference Jan 27-28)

Location: Lexington Convention Center, 430 West Vine Street, Lexington, KY 40507

Registration: $199 including Taste of Kentucky banquet

http://www.ssawg.org/2016-conference-program

Pam’s Workshop: Friday, 9:45 a.m. – 11:00 a.m.

Intensive Vegetable Production on a Small Scale — Learn techniques for raising large amounts of food on small acreages. Pam Dawling, who raises vegetables for a 100-person community on 3.5 acres, will discuss direct sowing and growing of transplants, close spacing, raised beds, irrigation, disease and pest management, and season extension techniques. This session will be valuable for small market farmers and urban farmers who want to maximize production with limited space.

Book Signing: Thursday, January 28 7:00 p.m. – 8:30 p.m.

Culpeper County Library, VA

Date: Sun, Feb 28, 2016 2-4 pm

Location: Culpeper County Library, 271 Southgate Shopping Center, Culpeper, VA 22701

Workshop topic: talk about my book, research, importance, etc. for 30 – 45 minutes, then 15 – 30 minutes Q&A. CSA Farmers at an info table. (National CSA sign up day)

Signing and selling books.

Organic Growers School, Asheville, NC

Dates: March Fri 11-Sun 13 2016.

Location: University of North Carolina Asheville, UNCA

Workshop topics: Growing Great Garlic – Planting, harvest, curing, storing and the selection of planting stock are comprehensively covered in this workshop. As well as both hardneck and softneck bulb garlic, this workshop covers “byproduct crops” such as garlic scallions and scapes, which are ready early in the year when new crops are at a premium.

Intensive Vegetable Production on a Small Scale — Raise large amounts of food on small acreages. Learn about crop planning and record-keeping, growing and maintaining healthy soils, using crop rotations, cover crops, organic mulches and the basics of compost making (and growing). Compare methods for direct sowing and growing transplants. Learn about plant spacing, raised beds, irrigation, disease, pest and weed management, and season extension techniques. For both small market farmers and urban farmers who want to maximize production with limited space.

Handouts

Workshops are 1.5 hours each

Signing and selling books.

New Country Organics, Waynesboro, VA

Small class, about 15 people

Date: Saturday March 26, 10am-noon.

Location: New Country Organics 801 2nd Street Waynesboro, VA 22980 To be confirmed

My contact: Jillian Lowery jillian.lowery@newcountryorganics.com

www.newcountryorganics.com 540-184-1956 844-933-3337

Workshop topic: Succession Planting

Handouts

Selling and signing books

Mother Earth News Fair, Asheville, NC (to be confirmed)

Anticipated Weekend Attendance: 15,000

Dates: Saturday April 9 – Sunday April 10, 2016 (to be confirmed)

Location: Western North Carolina Agricultural Center, 1301 Fanning Bridge Road,
Fletcher, NC 28732

Registration: $25 weekend pass.

Workshops: (to be decided)

Book-signing

Louisa Master Gardener class tour of TO gardens

Date: Thursday, April 21

Location: Twin Oaks Community

Heritage Harvest Festival

Dates: September 9-10 2016

Location: Monticello, near Charlottesville, Virginia

Tickets: TBD

Workshops: To be decided

Book-signing

Mother Earth News Fair, Seven Springs, Pennsylvania. (to be confirmed)

Anticipated Weekend Attendance: 18,000

Dates: Friday-Sunday September 23-25, 2016

Location: Seven Springs Mountain Resort, 777 Waterwheel Drive, Seven Springs, Pa. 15622

Registration: $20 weekend pass

Workshop topics to be decided

Book-signing

New Country Organics, Waynesboro, VA (to be confirmed)

Date: Saturday October??, 10am-noon. About 15 people

Location: To be confirmed: New Country Organics 801 2nd Street Waynesboro, VA 22980

My contact: Jillian Lowery jillian.lowery@newcountryorganics.com

www.newcountryorganics.com 540-184-1956 844-933-3337

Workshop topic: Cold Hardy Winter Vegetables

Handouts

Selling and signing books

Mother Earth News Fair, Topeka, KS (to be confirmed)

Anticipated Weekend Attendance: 12,000

Dates: October 22-23, 2016

Location: One Expocentre Dr., Topeka, KS 66612

Registration: $20 weekend pass

Workshop topics to be decided

Book-signing

Winter salad crops: Ruby Streaks. Photo McCune Porter — Winter salad crops: Ruby Streaks.
Photo McCune Porter

Meanwhile, here and now, on the ground, a photo of our much-beloved Ruby Streaks, in our Eat-All Greens patch, being used as salad greens.

CFSA report, SSAWG plans, a quiet time in between?

Carolina Farm Stewardship Association Sustainable Agriculture Conference

I’m home from the Carolina Farm Stewardship Association conference, and I had a great time. There were 1200 attendees and this was their 30th anniversary! I gave two workshops: Cold-hardy Winter Vegetables and Succession Planting for Continuous Vegetable Harvests, which I updated and you can view here:

Succession planting for continuous vegetable harvests 2015 Pam Dawling 90mins from Pam Dawling

I attended three good workshops by Steve Moore (High Tunnels/hoophouses), Ellen Polishuk (Coaxing more profit from your farm) and Laura Lengnick (Resilient Agriculture). It’s nice to have enough time at an event to attend other farmers’ workshops.

The November/December Growing for Market magazine is out. This double issue has 28 pages, with my article on succession planting in the winter hoophouse, and other articles on ginger, farm finances, and diseases in the winter flower greenhouse.

Practical Tools and Solutions for Sustaining Family Farms Conference
Lexington Convention Center ~ Lexington, Kentucky

You can see the full conference program with session descriptions at: http://www.ssawg.org/2016-conference-program

Pre-Conference Courses and Field Trips: January 27-28, 2016

General Conference: January 29-30, 2016
Visit www.ssawg.org for complete details

My workshop:

Intensive Vegetable Production on a Small Scale

Friday, January 29, 9:45 – 11:00

I’ll also be signing books on Thursday evening January 28, 7-8.30pm

Virginian Eat-All Greens on November 8 Photo by Lori Katz — **Virginian Eat-All Greens** on November 8
Photo by Lori Katz

Patchy Frost, Sweet Potato Harvest, Upcoming Events,

Jalapeno hot pepper plant with a fruit changing from green to red via black. Photo Bridget Aleshire — Jalapeno hot pepper plant with fruit changing from green to red via black.
Photo Bridget Aleshire

We had a very light touch of frost in the wee hours of Sunday October 11. The thermometer in the weather box recorded a low of 36F, but some of the pepper plants “recorded” something chillier. At this time of year we start our special frost season pepper harvesting technique. Instead of just harvesting fully colored peppers (and removing damaged ones), we harvest all peppers exposed to the sky, regardless of color or size. We’ve noticed that the first few frosts usually just nip the tops of the plants. So by harvesting exposed fruits we give the ones lower on the plant a bit longer to ripen, with the protection of the upper leaves. Next time there is a frost, another layer of leaves will get nipped and we’ll harvest another layer of peppers. This also has the advantage that we don’t have to deal with too many peppers at once. Eventually, of course, we’ll either harvest everything or give up. Often there are nice periods of mild weather in between the first few frosts. looks like next weekend will bring some more definite frosts.

Sweet potatoes and our last corn of the year. Photo from September, by Ezra Freeman

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. Then we were waiting for several key crew members to come back from helping harvest sorghum for syrup at Sandhill Farm in Missouri. Sandhill, like Twin Oaks, is an egalitarian intentional community. We have a labor exchange program between our communities in the Federation of Egalitarian Communities so that each community can ask for help from the other communities when they most need it and pay it back at another time. Work for a sister community counts as work for the home community. Sandhill asks for help at sorghum harvest. naturally enough this job appeals to members who do agricultural work at home. So we been short-handed in the garden for the past ten days.

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. . .

Meanwhile we have been working around a Big Ditch, which will soon connect our new grid-linked solar array to the main service panel. Life has been difficult, and the job is lingering because the Big Ditch filled with the heavy rains we had, then we found some unexpected old phone lines (and accidentally cut them). And then the supplies didn’t arrive when they should have. And so on. Everyone is probably familiar with projects which take a lot longer to complete than intended. Soon it will all be done, we’ll be able to disk and prepare the future garlic area take carts along the path again. And we’ll be using more of the sunlight to make electricity!!

Ditch for cables to connect up solar array. Raised beds on the right. Photo Bridget Aleshire — Ditch for cables to connect up solar array. Raised beds on the right.
Photo Bridget Aleshire

Upcoming Events I’ll be speaking at

The weekend of October 24-25 I will be at the Mother Earth News Fair in Topeka, Kansas with my two Hoophouse workshops:

I will be giving Fall and Winter Hoophouses as a keynote presentation on Saturday 10-11 am on the Mother Earth news stage and Spring and Summer Hoophouses
on Saturday at 1-2pm on the Organic Gardening Stage. I’ll be signing books at 11 am Saturday in the MEN Bookstore. I’ll be demonstrating How to String Weave Tomatoes using my sparkly-pink-tinsel and pencil model at the New Society booth 2055 on Saturday at 4pm, and Sunday at 10 am and 2 pm. If you want the pdfs of the handouts, click these links:

Hoophouse in Fall and Winter Handout

Hoophouse in Spring and Summer Handout

November 6-8 I will be at the Carolina Farm Stewardship Association Sustainable Agriculture Conference, in Durham, North Carolina. Click here for the Conference page. I’m doing two workshops, Cold-Hardy Winter Vegetables – on Saturday November7, 8.30-10am, and Succession Plantings for Continuous Harvests – on Sunday November 8, 10.45am-12.15pm. I will also do book signing at the BookSignAGanza, Saturday 5-6pm.

January 27-30 I will be at the Southern Sustainable Agriculture Working Group’s Practical Tools and Solutions for Sustaining Family Farms Conference in Lexington, Kentucky. On the website you can sign up for the e-newsletter and around October 15, you can do Early Bird Registration. I will be doing book signing on the Thursday evening Jan 28 from 7 – 8 pm, following the 25 Years in the Field talks by several people with a long history of contributing to the growth in sustainable and organic agriculture and local foods . I will be giving a 75 minute presentation on Intensive Vegetable Production on a Small Scale on Friday Jan 29, 9.45 -11 am. There are about 8 conference tracks (simultaneous workshops), and the conference ends on Saturday evening with a fantastic Taste of Kentucky Banquet and live music at the bar.

I hope to be at the Mother Earth News Fair in Asheville, North Carolina. Too soon to say for sure.

Events I’ll be speaking at, error found in SMF, book update

Cucumbers and squash in our hoophouse. Photo Nina Gentle — Cucumbers and squash in our hoophouse.
Photo Nina Gentle

First of all, I’ll get my confession off my chest. A savvy reader spotted an error in my book Sustainable Market Farming: Take a red pen and correct your copy!

In Chapter 20, Sustainable Disease Management, on page 135 I said “Pathogens can infect the seed via several routes . . . Insects that feed on the plant can transfer the disease (striped cucumber beetles vector bacterial wilt, which is caused by Erwinia tracheiphila)”

It is true that striped cucumber beetles vector bacterial wilt, which is caused by Erwinia tracheiphila. It isn’t true that this disease is seed-borne. I don’t know where I got the wrong information from. I don’t yet know of an example of a disease spread by insects that can become seed-borne (that I feel confident about!).

I’ve asked my publishers, New Society, to correct that mistake next time they reprint. I wrote to the attentive reader, thanked her, and asked her for leads on where to find information about seed-borne diseases brought in initially by insects.

**Organic Seed Grower by John Navazio, Chelsea Green Publishers**

Meanwhile, I can recommend two books on seed growing (that weren’t out when I wrote my book), that contain good information about which diseases are seed-borne. I reviewed the impressive The Organic Seed Grower by John Navazio a while back..

**The Seed Garden, from Seed Savers Exchange and Organic Seed Alliance**

Newer is The Seed Garden: The Art and Practice of Seed Saving from Seed Savers Exchange and the Organic Seed Alliance. Including “advice for the home gardener and the more seasoned horticulturist alike”, this is also a book from people who work growing seeds, and know their stuff. I plan to review it one week soon (when the work pace slows a little!)

If you’re a seed grower, you might want to add one of these to your wish list. Both are beautiful books, as well as clearly written ones.

This year I am not doing quite as much seed growing as some years. For sale, we are growing Carolina Crowder cowpeas in our hoophouse. Click the link to see photos.

For ourselves, we are selecting and saving seed from our Roma tomatoes and Crimson Sweet watermelon, as well as West Indian Gherkins. We are also saving garlic and shallots for replanting.

It’s that time of year when I line up events I’ll be speaking at in the fall and winter (and to some extent, into spring). Here’s my plan so far:

Friday and Saturday September 11-12 2015

Heritage Harvest Festival, Monticello, Charlottesville, VA.

On Friday, 1.30-2.30pm I will be offering one of the Premium Workshops, Crop Rotations for Vegetables and Cover Crops.

That’s at the Woodland Pavilion, Visitor Center.

Then I will be doing book signing at the tent called The Shop at Monticello (at the Visitor Center), 2.45-3.13pm.

On Saturday I will be offering another premium workshop, Producing Asian Greens. This one is at the Vegetable Garden Tent at the Mountaintop (where most of the Saturday events are). It’s immediately followed by another book-signing, 5.30-6.0pm. The Festival ends at 6pm. All day Saturday is packed with events, and a General Admission ticket will be all you need apart from tickets for premium Workshops.

The following weekend, September 18-20, I will be at the Mother Earth News Fair, Seven Springs, Pennsylvania. The schedule is not yet firm, but I will be presenting The Hoophouse in Fall and Winter probably on Friday September 18 4-5pm at the Mother Earth News Stage, and The Hoophouse in Spring and Summer on Saturday September 19 10-11am at the GRIT stage.

I will also be signing books at the Mother Earth News Bookstore at some point and doing some scale demonstrations of string-weaving for tomatoes at the New Society Publishers booth.

Hoophouse greens in November. Credit Ethan Hirsh — Hoophouse greens in November.
Credit Ethan Hirsh

The weekend of October 24-25 I plan to be at the Mother Earth News Fair in Topeka, Kansas with the two Hoophouse workshops. In February 2016, Mother Earth News is running their first fair in Belton, Texas. Too soon for detailed information yet, but watch the site, if you live in Texas.

February 3-6, 2016 I will be at the Pennsylvania Association for Sustainable Agriculture Conference at the Penn Stater Conference Center, State College, PA. Save the date.