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

Young greens in the hoophouse, nematodes, upcoming events

Young senposai transplant in our hoophouse.
Photo Pam Dawling

After the set-backs with our winter hoophouse greens  transplants that I wrote about last week, 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” .

Young Tokyo bekana transplant in our hoophouse .
Photo Pam Dawling

Ultimately if we don’t need them, they’ll go in a salad mix. I wrote about making 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.

Ruby Streaks transplant in our hoophouse. Compare with Scarlet Frills below.
Photo Pam Dawling
Golden Frills mustard transplant in our hoophouse. I harvested a leaf for salad mix yesterday.
Photo Pam Dawling
Scarlet frills mustard in our hoophouse. Notice that this crop is frillier than Ruby Streaks.
Photo Pam Dawling

The mix I made today had fewer ingredients. I left the frilly mustards, the lettuces and the Tokyo bekana alone to grow some more. I used Bulls Blood beets, spinach, tatsoi outer leaves and a few Bright Lights chard leaves and stems.

Cucumber roots with nematodes (see circles).
Photo Pam Dawling

I have a new Mother Earth News blogpost, about the nematodes in our hoophouse. And I’m preparing a new slide show for the Carolina Farm Stewardship Association conference. See my Events page for details

For those of you on other social media, here are their handles and links (use the hashtag #CFSAC2018).

This week we will be popping garlic for planting and having our Annual Garden Crop Review meeting. Next week I’ll tell you more about garlic planting as part of the Alliums for November post.

Popping garlic cloves in preparation for planting
Photo credit Southern Exposure Seed Exchange

Crop review, harvesting roots

Large Smooth Prague Celeriac
Photo credit Southern Exposure Seed Exchange

This week in the garden we have started fall clean-up. We packed away the rowcovers preserving the last rows of green beans, squash and cucumbers, and harvested the last of those crops. Two nights with lows of 22F made it clear it was time. We removed the okra and eggplant “trees”, and pulled up the t-posts from the tomato rows and the asparagus beans. We bundled the asparagus bean trellis netting, along with the bean vines, and tied it up in the rafters of our greenhouse. It will stay there till spring when we will dance on the bundle in the parking lot and shake out the dried bits of vine, so we can use the netting for the 2013 crop.

We discovered we can use our power-washer to clean the t-posts before storing them. This saves a lot of time, and converts the job from a tedious chore with knives and wire brushes into a “power rangers” opportunity. We like to get the posts really clean before storing them to reduce the chance of carrying over soil-borne tomato diseases to next season.

White Egg turnip
Photo credit Southern Exposure Seed Exchange

We have started clearing crops which are less cold-tolerant. This week we are working on the vegetables that get killed at temperatures of 25°F and 20°F. Fall weather in our part of Virginia doesn’t usually get this cold this early, but there’s no arguing with it. We’ve got the Chinese cabbage (Napa cabbage) in and we’re going for the small bit of bulb fennel soon (both 25°F crops). We’re picking the broccoli twice a week as long as it lasts, although yields are right down now. Next we’re after the celeriac, turnips (no rutabagas this year), and winter radishes. Sadly our fall beets all failed, so we don’t need to dig those. We still have some from the spring crop in good condition in perforated plastic bags in the fridge.  Kohlrabi, cabbage, carrots and parsnips are more cold-tolerant, so they can wait to get harvested in a few weeks. We still have lettuce and celery outdoors under rowcover and hoops. And some of the greens and hardier leeks will feed us all through the winter. Twin Oaks is now in Climate Zone 7a. This means the range of the average annual minimum temperature is 0°F to 5°F.

Popping garlic cloves in preparation for planting
Photo credit Southern Exposure Seed Exhcange

We’re getting ready to plant garlic. The soil has certainly cooled down enough this year! We decided to cut back our total amount of garlic planted this year for two or three reasons. One is that we think we’ll still have enough if we plant 16% less, and maybe we’ll be less wasteful. Another is that we hope the time we’ll save at harvest and curing will enable us to take better care of what we have got, and less will get wasted that way. Another is that it will help our crop rotation in the raised beds, where we grow a lot of alliums – garlic and potato onions over the winter, onions in spring, shallots and scallions in the mix, and leeks from mid-summer to late winter. Sometimes doing a smaller amount well is more productive than over-extending ourselves  with a big crop.

Yesterday we started separating the garlic cloves (“popping” the cloves) at our annual Crop Review meeting. This is when the crew gathers to work through an alphabetical list of crops we grew and talk about what worked and what didn’t and what we want to do differently next year. We plan to try a small amount of West Indian gherkins as an alternative to pickling cucumbers, which seemed plagued by disease. (I saw some very robust gherkins growing at Monticello in September.) We’re looking for a heat-tolerant eggplant variety to trial alongside our well-liked Nadia, which shut down during the early summer heat. We intend to make smaller plantings of edamame next year, and harvest smaller amounts more often, so less goes to waste. We want to try Sugar Flash snap peas and another dwarf early-yielding type of snow peas. (Dwarf Grey works for us, but Oregon Giant didn’t). We’re going to try some purple bush beans to see if that helps us get harvests of nice small beans and fewer ugly giants in the buckets. We debated the harvest size of okra and asparagus too. We vowed to grow fewer different varieties of broccoli and try to find a decent red cabbage. This year we tried Integro, Ruby Perfection and Mammoth Red, but none produced a good amount of nice sized heads. We used to be happy with Super Red 80, but gave it up after two bad years. next year we’ll try Red Express. We strategised about to get red sweet peppers as early as possible.

As the tasks to do outdoors start to wind down, we’re upping the pace of our winter planning season. Our next tasks include doing an inventory of the seeds we still have and figuring out our garden plan, so that we can work towards ordering the seeds we want in sensible quantities.

Twin Oaks October Calendar (Slowing Down)

Morris Heading Collards – our favorite
Photo credit Kathryn Simmons

Here’s our list of tasks for October. If you garden in zone 6 or 7, your list might be similar. If you live in a very different climate zone, leave a comment about your list for October, and how many weeks different your area is from ours.

During the month

Weed and thin fall crops in raised beds, especially spinach and kale. Thin carrots to 3”, kale to 12”.

Lettuce Factory: Transplant sowing #37 to fill cold frames; #38, 39, 40, 41, 42 in Greenhouse beds (9″ spacing).

Frost Alert:

Watch the forecast and if frost is expected that night

When frost threatens, harvest all peppers exposed to the sky. Corona is one of our favorite orange peppers. Photo credit Kathryn Simmons

Harvest peppers facing the sky, tomatoes, cauliflowers, corn, cowpeas, limas, eggplant, melons, cukes, okra, winter squash, Blues cabbage (hardy to 25°F), if not already done.

Double hoop and cover: lettuce, celery (hardy to 16°F with row cover).

Spring hoop and cover: squash, cucumbers.

Cover celery to extend the harvest into mid-winter. We like Ventura.
Photo credit Kathryn Simmons

Rowcover (no hoops): beans, Chinese cabbage, pak choy, Tokyo bekana, seedlings for hoophouse, collards  (hardy to 10°F, but cover keeps quality).

Cold frames:  Row cover between 32-28°F.  Add lids between 28-15°F.  Add quilts below 15°F.

Foliar spray greens with seaweed a few days before frost, to toughen them up.

Use overhead irrigation on peppers & tomatoes at night and some raised beds with tender crops.

Early Oct: Finish sowing spinach, kale by 7th for overwintering (last chance).

Transplant lettuce #37 to fill cold frames; #38, 39 in Greenhouse (9″ spacing).

Roll up drip tape from winter squash and sweet potatoes.

It’s time to roll up the drip tape from the watermelon, winter squash and sweet potato patches, in preparation for disking and sowing winter cover crops.
Photo credit Kathryn Simmons

Move stored garlic from basement to fridge – store below 40°F or above 56°F, never 40-50°F.

Mid Oct: Till finished raised beds and sow wheat or rye before the end of the month.

Garlic Beds: Compost (5-6 tractor buckets), till and prepare beds.

Transplant lettuce #40, 41, 42, 43 in Greenhouse as needed, filling any gaps.

Get soil tests done, when soil is not too wet.

5th fall disking: By mid-month disk and sow cover crops where possible. Sow wheat or rye as covercrops – too late for oats or most clovers (Austrian Winter Peas Sept 15-Oct 24).  Could sow winter wheat mid-Sept to early Nov (good for small plots that are hard to reach with the tractor) and after sweet potatoes).

Harvest peanuts mid-late Oct after a light frost.  Wash, dry, cure 6 days in solar dryer facing east (don’t heat over 85°F), store.

A well-covered sweet potato patch.
Photo credit Kathryn Simmons

Harvest sweet potatoes before soil temps go much below 55°F, or night air goes below 50°F: on 3 mild days – generally in the week that first frost usually occurs (10/7-14). Even a few hours exposed to temps below 50°F will cause chilling injury. (Frost on the leaves does not of itself damage the roots). Clip vines, dig carefully, set tubers in plant-clusters to dry on the soil. Select seed tubers (med-size tubers from high-yielding plants).  Save 100 Georgia Jet, 100 Beauregard, 20 each White and Jubilee. Cure in boxes with wood spacers and cover with newspaper, in basement with furnace going full time, for 7-10 days (85-90°F, 80-90% humidity).  Use fans. Splash water on floor. Curing is complete when skin is undamaged after rubbing two together. Restack boxes in storage cage.

Harvest white potatoes before the first frost (average Oct 14) if possible. Cure in root cellar at 60-75°F for 2 weeks, with good ventilation, then cool the cellar to lower temperatures: 50°F by 10/31, then 40°F for the winter.

Late Oct: Transplant lettuce #44, 45, 46 as filler in Greenhouse. Double hoop and cover spinach.

Planning: List successes & failures from labels. Prepare Garden Planning Schedule, Crop Review Sheets. Clean labels after info is recorded. Pray for a killing frost. File crop record info. Audit labor budget and plan endgame. Plan main garden layout. Hold Crop Review meeting.

Clear winter squash, tomatoes and peppers in order to sow cover crops, by 10/24 if possible. Sow rye alone or with crimson clover or winter peas. Crimson clover by 10/14; AWP, wheat by 11/8

6th fall disking: After the killing frost, or end of Oct if no frost: pull up tomato stakes and roll up drip tape, disk nightshades, melons, winter squash, sweet potato and white potato patches.

Check through veg in storage, squash once a week, white potatoes two weeks after harvest.

Perennials:Last mowing of clover in grapes in early Oct, not too short, and not too late in the year. Weed & mulch strawberry beds, and remove extra runners. Renovate if not already done. Start weeding, fertilizing and mulching the blueberries, raspberries, rhubarb and grapes.

Time to say goodbye to the rhubarb until April.
Photo credit Kathryn Simmons

October Harvests: Asparagus beans, beans, beets and beet greens, broccoli, cabbage, cantaloupes, carrots, cauliflower, celeriac, celery, chard, Chinese cabbage, collards, corn, cow peas, cukes, edamame, eggplant, horseradish, hot peppers, kohlrabi, komatsuna, leeks, lettuce, limas, maruba santoh, okra, pak choy, peppers, radishes, Roma paste tomatoes, scallions, senposai, spinach, tatsoi, tokyo bekana, tomatoes, turnips and turnip greens, winter radishes, winter squash, yukina savoy, zucchini.  Could lightly harvest rhubarb before frost.