Our hoophouse beds after the nights at 2F (-17C) and 8F (-13C). Looking amazing! Pam Dawling
We were luckier with the weather than many people over the weekend (12/23-12/26/2022). And so were our vegetable crops. On Friday 12/23 we prepared for a suddenly very cold night. It was very windy as we battled to stop the hoophouse windows from blowing open. We finally got some shims, a hammer and a stepladder, and wedged them closed. They stayed that way until Tuesday 12/27. We were fortunate in getting no precipitation (I hate ice!) and no power outage.
Pool noodles repurposed as draft excluders. Pam Dawling
We fortified the doors with our rock collecting buckets, and prevented most of the under-door drafts with our pool noodle draft excluders. They have a rope running through them, which is hooked onto small cup-hooks on the door frame. We repurposed noodles that had been used as props at a party or some other kind of event. They had been covered in tube socks and had glued-on googly eyes.
Rolls of rowcover at the ready in our hoophouse. Pam Dawling
It was a bit unnerving being in the hoophouse as it creaked and groaned in the wind. In the winter we keep rolls of rowcover ready for any night we think will be below 8F (-13C). We unrolled the rowcovers by lunchtime and laid tools on the ends nearest the doors. I was worried that if we lost power, and therefore the inflation, it would get very cold indeed in the hoophouse.
The DIY manometer in our hoophouse. (the background lines have faded). Pam Dawling
Since we last changed the plastic we haven’t managed to get the recommended 1/3” (8.5mm) pressure difference in the “bubble” between the plastic layers, compared to our normal air pressure. Mostly we don’t even get ¼” (6.5mm). The “bubble” provides thermal insulation as well as physical strength against snow or ice buildup, and strong winds.
It got down to 2F (-17C) outdoors Friday night, and Saturday didn’t warm up much. I don’t actually know what the night temperature was in the hoophouse as our recorded low temperatures don’t make sense: 14F (-10C) for four consecutive nights (Fri to Mon). I suspect we didn’t reset the thermometer correctly. Usually the hoophouse can hold 8 F (4.5 C) degrees warmer than outdoors, but not 12 F (7 C). It looks like it did, perhaps because we didn’t open it all day!
Soil thermometer in our hoophouse on 27 December 2022. Pam Dawling
The soil is still nice and warm in there: 59F (15C). That really helps. The rowcovers are usually removed in the daytime, either pulled aside if we expect to need them again the next night, or rolled up out of the way. Most of the time they stay rolled up at the east end of the hoophouse. We appreciate not needing to deal with rowcovers most of the time! On Saturday 24th, the temperature maximum for the day outdoors was 24F (-4.5C), and we kept the rowcovers in place over the crops. On Sunday the high outdoors was 28F (-2C) so we pulled the rowcovers aside until the night. On Monday 26th the night-time forecast was benign enough that we rolled the rowcovers up. And now we get a milder spell.
Hakurei turnips with frozen yellow leaves where they touched the plastic (rowcover protected the plants). Pam Dawling
How did the crops fare? It’s not always obvious at first if a crop has been killed by cold or not, But I can now say with confidence that nothing died. The edge beds are always the coldest. The south edge bed had Hakurei turnips, delicious and notoriously the least cold-hardy turnip variety. Most of the globe of the turnip sits on the surface of the soil. You can see in the photo that some of the leaves, the ones right by the wall plastic, have been killed and turned yellow. But the roots themselves (with rowcover over them) seem fine.
Bright Lights chard with cold-damaged stems in our hoophouse north edge bed after nights at 2F and 8F Pam Dawling
Over the other side, in the north bed, we have some Bright Lights chard, among other things. Multi-colored chards are less cold-hardy than red ones, which in turn are less cold-hardy than green ones. We know we take a risk in growing Bright Lights through the winter, but we so enjoy the sight of the short pieces of colored stems in our salad mixes that we take the risk. Some of the stems have curled over, probably on their way to dying, but the plants live on, to provide many more salads this winter! And some cooked greens too.
Some of the giant senposai leaves, where not fully protected by the relatively narrow rowcover, have developed tan dead spots, so those leaves can just continue as the plants’ solar panels until we get tired of looking at them and decide they are no longer needed.
Each winter I update my Winter-Kill Temperatures of Cold-Hardy Vegetables list, except this past spring I had nothing new to add. Outdoors, I noticed today that the tatsoi has definitely died, the Vates kale and the spinach have survived (uncovered) and the small garlic leaves don’t seem troubled. The leftover lettuce transplants have been damaged, if not killed.
Our hoophouse with a December snowfall. Pam Dawling
We’re solidly in the darker and colder half the year for our monthly series of 14 Workhorse Crops (asparagus, beans, cabbage, carrots, chard, collards/kale, garlic, potatoes, sweet corn, sweet potatoes, tomatoes, watermelons, winter squash, zucchini/summer squash). These crops are reliable and productive under a range of conditions. You can use the search box to find previous month’s entries, such as December.
Winter is a natural opportunity to reconsider the size of your garden, which crops to grow, and your growing methods. Perhaps this will be your first gardening year? If so, welcome! Use the search box to find specific info, or click the blog category to find some further reading. Hopefully, we all have our garden plans made and our seeds ordered. Maybe we are already looking at a planting schedule.
In January, we can plant small small potato onions outdoors. We prepare the bed in the late fall and mulch it with hay, to plant in January. We rake off the mulch, plant the onion bulbs and then lay the mulch back on the bed, to control weeds and somewhat to insulate the little onion bulbs. These smallest potato onions are very cold-hardy, and will grow up to produce a single 3” (7.5 cm) large onion. A few will grow and subdivide to produce more small onions. Click the link to read the details.
Indoor sowings for later transplanting outside or in the hoophouse
In our greenhouse we fire up our germinator cabinets and sow our first lettuce and early cabbage (Early Jersey Wakefield and Faroa) and scallions in mid-January. The following week we sow our tomatoes to plant out in the hoophouse, and at the end of the month, spinach if we have not got enough sown in our hoophouse to transplant as bare-root transplants.
Flats of cabbage seedlings in our greenhouse. Photo Pam Dawling
Hoophouse workhorse crops to plant in January
In the hoophouse we are sowing a second or third round of crops, mostly successions of greens and radishes. We have already pulled our first and second radishes, and some of the Asian greens.
This March we will be using a half-bed in the hoophouse for some early green bush beans. Like our other warm weather crops, these can be planted in the hoophouse a month earlier than outdoors. Two cautions with green beans in the hoophouse: buy a very upright variety, as the plants will be more sprawling than they are outdoors. Outdoors we grow Provider and Bush Blue Lake (both very reliable and productive), and in the hoophouse we like Strike. The second bean caution is that we have found the edge beds too cold for beans when we need to sow them, in March. Don’t plant them now, but order seeds of an upright variety and plan a non-edge bed. I’ll say more in March.
We have also planned our next round of early warm-weather crops, which we will transplant in late March and early April. Tomatoes and zucchini/summer squash are on our Workhorse list
Young spinach seedlings. Photo Pam Dawling
We stop filling gaps in most of the Asian greens at the end of December, because they will start to bolt in January and/or because they are mature and we will be clearing the space to sow something else. Tatsoi, Tokyo Bekana, Pac Choi, Chinese Cabbage, Yukina Savoy, all need to be eaten during January. We sow spinach (the Racehorse Crop) in mid-January, to transplant in the hoophouse and outdoors.
Vates kale seedlings for bare-root transplanting. Photo Pam Dawling
On January 24 we sow Vates kale and Morris Heading collards in the ground in the hoophouse, in the space recently freed up by the Chinese cabbage. For 1080ft outdoors, we need 108ft of seedling rows. We can fit 14 rows of seedlings across a 4ft (1.2 m) bed.
See November’s information on Follow-On Crops, and Filler Greens (short rows of greens sown in October to fill unexpected spaces).
Workhorse Crops to Harvest in January
We still have workhorse crops to harvest outdoors: chard, kale and collards, and perhaps cabbages. We’re down to three of our 14 workhorse crops to harvest outdoors in January, but we have the Racehorse Crop, spinach, too, and also luscious hoophouse greens.
Deadon (105d winter cabbage) is extremely cold hardy – we leave it outdoors until nights threaten to hit 10°F (-12°C), the lowest temperature I’ve seen it survive. We just had one night at that temperature, much colder than anything else so far this winter.
Chard can still be harvested outdoors if we covered it with hoops and rowcover. The outdoor killing temperature for unprotected Bright Lights chard is 22°F (–6°C); red chard survives down to 15°F (–9.5°C) and green chard to 10°F (–12°C). We have succeeded in keeping chard alive outdoors right through the winter, if we cover it.
Collards and Kale can be lightly harvested in January. Our mnemonic for sustainable harvesting of leafy greens is “8 for later”, meaning we leave at least eight inner leaves when harvesting the outer ones, to ensure the plants have enough strength to regrow. In October, November, February and March, we can harvest leaves from these plants once a week. In December and January, once each month is more like what we can hope for. Chard and senposai do OK with only 6 leaves left.
Hoophouse Workhorse harvests in January
We are harvesting leaves from our hoophouse Bright Lights chard at an adolescent size, cutting them into ribbons, and chopping the colorful stems, for salad mixes. Later, when the days lengthen, we’ll be able to harvest leaves for cooking.
Red Russian kale in our hoophouse Photo Pam Dawling
The Red Russian and White Russian kales are ready to harvest now (we were a bit late with getting a successful sowing in September). Russian kales belong to the napus group of kales, which are better able to make growth in low light levels than oleracea types like the Vates we grow outdoors. Vates is our star outdoors, because it is more cold-hardy than any other kale I’ve found. The Russian kales have a tendency to wilt after harvesting, so we move fast and stand the leaves up in the buckets. We add some water to the buckets before rushing them to the walk-in cooler. (We do this with chard, turnip greens and Tokyo bekana too.)
The hoophouse senposai is on its third round of harvests, just two weeks after the second, which was one week after the first. This clearly demonstrated the slower rate of growth as temperatures and daylight decrease. The short days do cause plant growth to slow down, but this is not the only factor. Soil temperature is another. In our hoophouse, the soil temperature is still 50F (10C) in early January.
But hey! The length of daylight is now increasing! On the shortest day, December 21, we have 9 hours and 34 minutes of daylight, from 7.21 am to 4.55 pm. The mornings continue to get darker by a few minutes, taking a month to get back to 7.21, from a latest of 7.25 am. Meanwhile the evenings are getting lighter, gaining us 6 minutes by January 5. I’m typing this on my laptop onto a USB stick, as we are in day 3 of a power outage. I appreciate the lighter evenings! By January 21 we will be up to 10 hours of daylight!
Workhorse Crops from storage in January
Storage crops come into their own in December and January, once outdoor growth has slowed down. The flavor of stored sweet potatoes reaches its peak in late January! Besides the Workhorse Crops of carrots, potatoes, sweet potatoes, winter squash and garlic, there are many other root crops. See my posts Root Crops for the Month. Use hardneck garlic first, as it stores for only for 4-6 months. Softneck garlic can store for up to 7 months.
Eat up your acorn and other pepo types of winter squash, as they store for only 1-4 months. Maximas such as Cha Cha, Jarrahdale and Kabochas store for 3-5 months; Moschatas such as Butternuts and Cheese pumpkins will store for 8 months or even more. Seminole pumpkin can easily store for a whole year at room temperature. They do have hard shells and need a hefty cleaver to cut them open.
Our white potatoes are keeping well in the root cellar down at 40F-50F (5C-10C). We air it about once a week. We open the door on mild nights or chilly overcast days, depending what we get and what we need. Potatoes in storage after their first month are no longer respiring much at all. They should be dormant, and not in need of many air changes.
Sweet potatoes on a plate. Photo Brittany Lewis
Our sweet potatoes are very delicious. We are eating about 40-50lbs (19-23 kilos) a week.
Stored cabbage can also be a boon, and this is also a good time to explore all the pickles and canned and frozen produce you put up earlier.
Workhorse Crops Special Topics for January: Making Schedules.
We continue our Garden Planning, ordering seeds and planning schedules of field planting and greenhouse seedling starting. In January we start sowing seeds indoors, and need our schedule figured out for that. We also need to pay attention to germination temps for various crops, so that we get them off to a good start, matched with crops needing similar temperatures in each germination cabinet.
Here I will tell you more about storage of various crops.
Storing crops maximizes their season of availability
Many crops can be stored without electricity, perhaps in buildings that serve other uses at the height of the growing season.
The Washington State University Extension publication,Storing 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
There is also good information in old versions of the USDA Agriculture Handbook 66.
Some vegetables need to cure before storage in different conditions from those needed for storage. Curing allows skins to harden and some of the starches to convert to sugars.
A storage cabbage, with curled-back leaf on the head, showing maturity. Photo Bridget Aleshire
Four Sets of Vegetable Storage Conditions
See the chart in my book Sustainable Market Farming, for more details.
By providing storage spaces with just 4 types of conditions, at least 25 crops can be stored.
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. Use ventilated crates, or perforated plastic bags (or mesh net bags for cabbages) indoors. If above 45°F (7°C), roots will start to sprout. Greens benefit from light. See more about root cellars below. Roots can be stored in clamps or pits outdoors – more on those options below.
B= Cool and FairlyMoist: 40°F–50°F (5°C–10°C), 85%–90% humidity — root cellar. Potatoes. Use ventilated crates. Keep in darkness to prevent greening. See the links to my potato storage info.
Trimming garlic stems prior to long-term storage. Photo by Brittany Lewis
C=Cool and Dry: 32°F–50°F (0°C–10°C), 60%–70% humidity — cooler basements and barns. Garlic and onions. Use net bags or shallow racks. Avoid temperatures of 40°F-56°F (4°C-13°C), or they will sprout. Also avoid reversals of temperature (warm conditions after cold ones). Newer info says 32°F-40°F (0°C-4.5°C). is best for garlic.
D=Warm and Dry to Fairly Moist: 50°F–60°F (10°C–15°C), 60%–70% humidity — basements. Sweet potatoes and winter squash. Use shallow racks or perforated trays. Sweet potatoes need curing at higher temperatures and humidity before storing.
The entrance to our root cellar.Photo Twin Oaks Community
Root Cellars
Potatoes can be stored for five to eight months with a good in-ground root cellar.
Potatoes are best stored in a moist, completely dark cellar, at 40°F (5°C) to 50°F (10°C). Ventilate as needed for air exchange and to keep the cellar in the ideal temperature range.
Also for apples, cabbage, or root vegetables, but be careful what you mix, because ethylene from the apples, for example, will cause potatoes to sprout!
Some people pack unwashed vegetables in boxes of sand, wood ash, sawdust or wood chips. Perforated plastic bags are a modern alternative.
Cabbages or pepper plants can be hung upside down in the cellar to ripen, or simply to store.
Celery and leeks can be replanted side by side in tubs of soil.
See Nancy and Mike Bubel’s book Root Cellaring to learn how to design, build and use a root cellar.
Using a sturdy digging fork to harvest leeks in December. Photo Pam Dawling
In-Ground Storage
Depending on your winter temperatures, some cold-hardy root crops (such as turnips, rutabagas, carrots, parsnips, Jerusalem artichokes and horseradish) and also leeks can be left in place in the ground, with about a foot (30 cm) of insulation (such as straw, dry leaves, chopped corn stalks, or wood shavings) added after the soil temperature drops 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.
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 storage this way.
In colder regions plan to remove the crops before the soil becomes frozen, or else wait for a thaw.
Drawing credit WSU Storing Vegetables and Fruits at Home
Harvested turnips ready for storage. Photo Pam Dawling
Storage Clamps (Mounds)
Cabbage, kohlrabi, turnips, rutabagas, carrots, parsnips, horseradish, Jerusalem artichokes, salsify and winter radishes can be stored with no electricity use at all, by making temporary insulated outdoor storage mounds (clamps).
Mark out a circular or oval pad of soil, lay down some straw or other insulation, pile the roots up in a rounded cone or ridge shape, and cover them with straw and then with soil, making a drainage ditch round the pile. As a chimney for ventilation, leave a tuft of straw poking out the center. Slap the soil in place to protect the straw and shed rainwater.
For the back-yarder, 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, although it takes some care for it to be successful.
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.
Drawing credit WSU Storing Vegetables and Fruits at Home
Pits and Trenches
Dig a hole in the ground, line it with straw, lay in the vegetables, then cover with more straw and soil.
To deter rodents, bury large bins such as metal trash cans, layer the vegetables inside with straw, and cover the lid with a mound of more insulation and soil.
Trenches can have sidewalls made with boards to extend the height.
You can bury insulated boxes in the ground inside a dirt-floored shed or breezeway. Insulated boxes stored in unheated areas need six to eight inches (15–20 cm) of insulation on the bottom, sides and top.
Drawing credit WSU Storing Vegetables and Fruits at Home
Cherokee Purple tomatoes. Don’t store ripening tomatoes with your potatoes! Photo Southern Exposure Seed Exchange
Ethylene
Ethylene is associated with ripening, sprouting and rotting.
Some crops produce ethylene in storage — apples, cantaloupes, ripening tomatoes all produce higher than average amounts.
Chilling, wounding and pathogen attack can all cause damaged crops to produce ethylene.
Some crops, including most cut greens, are not sensitive to ethylene and can be stored in the same space as ethylene-producing crops.
Other crops are very sensitive 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.
Drawing credit WSU Storing Vegetables and Fruits at Home
China Rose Winter Radish. Photo Seed Savers Exchange
You can find a wealth of information on my website about growing, harvesting and storing winter vegetables. There are many links here in this post (all should open in a new tab, so you won’t go down a rabbit hole), and you can also use the search box in the upper right to enter whatever vegetable you are wondering about, and “grow” “harvest” or “store”, Remember I also have several annual series of posts, on Asian greens, root vegetables, workhorse crops, alliums, cooking greens, and lettuce. Just don’t look for “Storage lettuce” until April 1st.
I’ve also included some good blogs that I sometimes consult.
Fall and Winter Vegetable Growing
Season extension into cold weather
Prepare your garden for colder weather: plant winter crops if there is still time, use rowcover on hoops to protect crops from wind and cold weather, plant up every little bit of space in your greenhouse or hoophouse.
Shannon suggests using a variety of strategies. “Plant some vegetables that will mature quickly, others that will hold well in your garden beds, and still others that will overwinter and begin growing again when the days lengthen.”
Good late season vegetables: salad greens, Swiss chard, beans, peas (in climates milder than 7), carrots, radishes, senposai, spinach, pak choy, cabbage and winter lettuces.
Good cold hardy vegetables: Plant in late summer and fall to harvest throughout the winter. These late-sown crops reach full maturity before seriously cold weather, and hold so you can harvest them when the rest of your crops have been eaten. They don’t usually grow much during the winter, but they do stay fresh. Grow enough to supply your needs without depending on any further growth. This category includes Asian greens, beets, broccoli, Brussels sprouts, cabbage, carrots, collards, kale, leeks, scallions, spinach, turnips and other root vegetables,
Good crop protection so you can grow some crops through the winter. If your winter temperatures routinely drop below 25 F (- 4 C), crops need protection, from simple rowcover to hoophouses or greenhouses. This improves the temperatures, but it’s hard to address the reduced amount of daylight or sunlight. The increased warmth, plus the protection from winds, can be enough for some, such as spinach, kale and lettuce, to make some growth whenever their temperature is greater than 40F (5C).
Using a sturdy digging fork to harvest leeks in December. Photo Pam Dawling
Good slow growing crops to harvest outdoors in late winter or early spring. In this category are crops that go into the winter less than fully grown. After the winter solstice, when the days begin to lengthen, crops start growing again, making them usually ready for harvest very early, much earlier than any crops planted after the solstice. They don’t usually need winter protection and include beets, some types of broccoli, cabbage, carrots, collards, kale, onions, garlic, garlic scallions, spinach, kale and collards.
Good crops to grow in hoophouses include arugula, beets, chard, Chinese cabbage, collards, kale, lettuce, Maruba Santoh, mizuna, mustards, pak choy, parsley, radishes, spinach, tatsoi, Tokyo bekana, turnips and Yukina Savoy
Hoophouse Bright Lights chard in winter. Photo Wren Vile
A list of seven basic principles of harvesting, followed by a crop-by-crop list of almost 50 individual crops and a resource list of 18 publications (focused on the mid-Atlantic and Southeast)
Sweet potatoes in storage. An ideal crop for winter meals, as they store at room temperature for a long time, maybe seven or eight months. Photo Pam Dawling
Young Cylindra beets in early May. Photo Pam Dawling
Root Crops to Plant in Central Virginia in April
We are in cold-hardiness zone 7a, with an average last frost of 4/29. Those in other climate zones can study our Root Crops in May or Root Crops in March for information more useful in their area.
Outdoors we can sow carrots #4 & #5, parsnips, radishes #2, (last date 4/15, sow on the shoulders of a newly transplanted lettuce bed to save space), beets (last date 4/15, hand sown or with an EarthWay seeder Chard plate, 2 or 3 passes. 1 cup sows 360 ft/110m)
It is too late for us to sow any root crops in the hoophouse. (Besides, we want tomatoes!)
Having good stored crops like these beets will feed you through the Hungry Gap. Photo Pam Dawling
Root Crops to Harvest in Central Virginia in April
As in January, February and March in central Virginia, in most of April there are still no roots to harvest outdoors except overwintered parsnips and maybe carrots, Jerusalem artichokes and horseradish. Radishes from the first outdoor sowing will be ready at the end of April. We can usually harvest radishes until the end of May. Our hoophouse radishes usually finish in early April. By then it is hot and any remaining radishes bolt.
From storage, if we still have them, we can eat beets, carrots, celeriac, kohlrabi, parsnips, potatoes, rutabagas, sweet potatoes, and turnips.
This is the Hungry Gap (see Special Topic for April below)
Colorado Potato beetle late stage larva Photo Pam Dawling
Other Root Crop Tasks in Central Virginia in April
If you are growing your own sweet potato slips, cut 6-12” (15-30cm) slips daily and stand them in water. Once a week, plant rooted slips in 4” (10cm) flats.
Hill up potatoeswhen 6” (15cm) high. Cover half the vine. Repeat after 2 weeks. This deals well with weeds and gives the potatoes more soil to grow into.
Potato beetles: Use Spinosad [or Neem] once larvae are seen, if there are more than 50 adults/50 plants or more than 200 larvae/100 plants. If you have fewer, you can leave them alone. Spinosad: Spray when bees are not flying (early morning or late evening.) Shake well, 1-4 Tbsp/gall (1fl.oz=2Tbsp=30ml.) Approx 8-30 ml per liter. Repeat in 6 days. Clean and triple rinse the sprayer. Do not flush Spinosad into creeks or ponds.
Mow cover crop mixes in late vegetable plots when rye or wheat heads up, to help legumes develop.
Take rowcover from turnips that were sown 3 or more weeks earlier, to use on newer and more tender crops.
Till beds you’ll plant in a week or two, as heavy rain may prevent tilling close to sowing time. My ideal is to till as deep as needed ahead of time, then do a superficial tilling or scuffle hoeing the day before planting. This gives the best weed control.
Spread compost on beds you’ll plant in 3 weeks or so, and till in the compost when the soil is not too wet, not too dry.
If exposed to 10 consecutive days below 45°F (7°C), celeriac will bolt.
Store spring and fall seeds (spinach, peas, beets) in a cool place for the summer.
Vates kale outdoors. An oleracea type, Vates is very cold-hardy. Photo by Nina Gentle
Special Root Crop Topic for April in Central Virginia: the Hungry Gap
What is the Hungry Gap?
The Hungry Gap happens in temperate climates with four seasons. In winter the short day-length reduces plant growth, and when it’s cold, maybe damp, windy, and overcast, the rate of crop growth drops further. The Hungry Gap is the annual period of the shortfall in local fruit and vegetables. April is the leanest month of the year in northern temperate climates, and the period can extend from January to May. This may be a factor in the origin of the 40 days of Lent.
Spring is not the time of overflowing bounty you might expect – leaves are growing, but not much else. Depending on your particular climate, there may be some vegetables that are winter-hardy. Almost every vegetable lover yearns for more variety than that!
In the spring, any remaining winter vegetables are getting ready to bolt(produce flowers and seeds rather than more leaves). Growers and gardeners are enthusiastically sowing and transplanting new crops, but planting too early would be a sad mistake and it takes time before those new crops can be harvested. That gap between the last of the winter crops and the first of the early spring crops, is called the Hungry Gap.
It’s not a familiar term these days, because importing produce from warmer climates hides the reality. Vegetable consumption in much of the Western hemisphere has shifted from Medieval (leaves and roots) to Mediterranean (“ratatouille vegetables” and salads). Importing or long-distance hauling demands more energy usage, as does the refrigeration they often require in transit.
Also there has been a practice of growing vegetables with artificial heat and light. This is not ecological, as use of fossil fuels contributes to climate change. The food sector accounts for 30% of global energy consumption and produces about 20% of GHG emissions (see the 2011 FAO report). Most of this energy consumption comes from oil and gas in the form of artificial fertilizers and pesticides, on-farm machinery and food processing.
Sweet Potatoes in storage. Photo Pam Dawling
Sustainable Ways to Bridge the Hungry Gap
How did people survive the hungry gap in times gone by, and what can we learn from those strategies? Eating in the hungry gap used to be both hard and uninspiring – a restricted diet with few options. Adding options involves advance planning and advance work.
Use stored food, such as root crops, winter squash and pumpkins
Preserve fruits and vegetables from other seasons. Consider jams, pickles, canning in jars, freezing, drying, salting and fermenting (think sauerkraut)
Grow more winter-hardy crops that start regrowth early in the spring, and may be harvestable during the winter. Consider covering the rows with rowcover or polyethylene low tunnels.
Grow more perennial crops, such as asparagus, rhubarb, sea kale and sea beet (Beta vulgaris subsp. Maritima, wild beet). Although they take several years to establish, they will then yield earlier in the year than crops grown from seed in spring. Asparagus and rhubarb provide new flavors early in the year and signal the change to come.
Asparagus in early April. Credit Wren Vile
Sow fast-growing cold-hardy crops as early as possible after the winter solstice, for example spring leafy vegetables such as spinach, kale, collards, fast cabbage varieties, and lettuce.
Add crop protection in the form of rowcovers, low polyethylene tunnels (cloches), caterpillar tunnels, high tunnels (hoophouses, polytunnels) to create a warmer environment, trapping heat and humidity and warming up the soil, providing earlier harvests. Protect early sowings of quick crops, like radishes, arugula, land cress, salad greens, and also the first few weeks of newly planted kale, collards, spinach, mizuna, pak choy).
Forage sustainably for edible wild greens as a spring ‘tonic’, even if not a major item in your diet. The strong flavors provide a welcome change after repetitive winter vegetables, and a useful top-up to the supply of produce as stores run low. Spring is one of the best seasons for foraging, but you do have to reliably identify what you’re picking, so get yourself a good guide book or phone app. Ramps, nettles, violets, chickweed, dandelion, garlic mustard, and lamb’s quarters are some of the many wild greens available in spring. See Rustic Farm Life: Wild Spring Greens You Should Be Eating
Ruby chard. Photo Kathryn Simmons
Maximize the number of annual and biennial crops you grow that are in season during the Hungry Gap. Some are mentioned already. Here are more ideas: chard, globe artichokes, herbs, Jerusalem artichokes, kale (one variety is called “Hungry Gap” because it crops during this period. It was introduced to UK agriculture during WWll in 1941), leeks. If your winter climate is mild enough (zone 8 or 9): over-wintered Purple sprouting broccoli, and spring greens (immature close-spaced dark-green cabbages).
Brassica oleracea ‘Hungry Gap’ – kale Photo Chiltern Seeds, UK
Indoor gardening. Grow sprouts and microgreens. These don’t take much advance planning and can perk up a winter or spring meal. Microgreens grow in compost or on special “blankets”, but sprouts are generally grown in jars or trays. Pea shoots are an easy one to start with, and you can use dried peas from the supermarket. When sprouting it is important that you buy organic seeds, to be sure that they have not been treated with any chemicals. Rinse your sprouts twice a day, and keep everything clean.
Next month I will start a new monthly series. Workhorses are crops that are reliable under a wide range of conditions, including weather, soil, date and other variables. Some are easy to grow, some pump out lots of food, some are “insurance crops” like chard that stand in your garden until you need to harvest them. Part of my motivation for this series is to help all the “Covid-steaders” who started growing food during the pandemic and want to up their game without investing a lot more time. Part is to help established gardeners and growers who need to make a living while dealing with the changes the past year has brought to their markets and to our climate. We need some easier days!
We shovel many wheelbarrows full of compost to our raised beds every year. Photo Wren Vile
Root Crops to Plant in Central Virginia in March
As soon as the soil is dry enough and not frozen, we spread compost on the raised beds we plan to plant in February and March, and till in the compost. We make ourselves a Spring Start-up Plan, so we know where to focus our energy when the weather gives us a chance.
Spring Start-up Plan
We aim to spread compost 4-6 weeks before planting, rototill 2-4 weeks before planting, and prep the bed a week or two before. This is more time than we allow later in the year, but in early spring it’s good to seize the opportunities that arise and not take the weather for granted.
This means in January we compost and till beds for spinach, turnips and our first carrots. In the first half of February we till the turnip beds and any beds of winter-killed oats cover crops that we will be planting soon. We compost the first lettuce bed, the kale and collard beds, and those for cabbage, beets, more carrots, senposai and peas (all have planting dates March 9 to 15). In the second half of February, we compost the third carrot bed and till the ones we already composted. In early March we till the third carrot bed.
A bed ready for tilling after mowing the cover crop and spreading compost. Photo Pam Dawling
Once we get to March, day length has increased and temperatures are starting to climb. There is a noticeable increase in the rate of germination and growth (unlike for our February sowings, which are rooted in faith and optimism!) All being well with the weather (it’s extremely wet this year!), in early March, we direct sow turnips (3/6- 3/16), and radishes #1 (Cherry Belle or some other fast variety)
In mid-March, we can transplant kohlrabi. And we direct sow carrots #3 and beets. See below for more about beets. In late March, we direct sow our carrots #4, and more radishes and beets. We can sow kohlrabi if we have no transplants, and thin to 6” (15 cm) later.
Potatoes
A row of potato seed pieces ready to cover. Photo by Wren Vile
We plant potatoes when the daffodils bloom, usually mid-March. Last year I wrote an extensive series of posts about growing potatoes.
Detroit Dark Red beets in early June sunshine. Photo Pam Dawling
Beets are workhorse root crops that thrive in mild weather, store well, and are popular traditional foods. They are crops that can provide high yields for the time invested.
Beets come in several types, round, top-shaped and long. The size and quality of the greens is a factor if you sell bunched beets with tops, or use the tops for greens. We like the 6” (15cm) long Cylindra/Formanova/Forono ones (55 days to maturity, OP). They are very tender and easy to cut into regular slices, for pickles or cooking. The skins come off easily, and the flavor is very sweet and the texture tender.
Among round ones we like Ace (50 days to maturity, F1 hybrid), and Detroit Dark Red (60d), a tender open-pollinated variety. Detroit Crimson Globe is said to maintain better flavor in hot weather than most others, which can develop off-flavors. Early Wonder Tall Top (48d), is also open-pollinated. Lutz Green Leaf (70d) is a big long-storage variety. There are also golden beets, white beets and candy-striped Chioggia beets, although in my experience, what they gain in appearance they lose in flavor and tenderness.
Beets seeds average 35,000 /lb. 2,200/oz, 80 seeds/gm. 1,285 seeds (2/3 oz, 18gm) sow 100’ (30m).150’/oz, 2,300’/lb., 9 lbs/acre. 315,000 seeds/acre. Yield can be 40 lbs. (18kg) greens, 100 lbs. (45kg) roots/100’ (30m), or 14,000 lbs/acre, 2540 kg/ha.
Beets need a pH of 6.0-7.0, preferring 6.5-6.8.They require abundant potassium, which can be supplied by woodash.Boron deficiency can show up in beets as internal browning, or dark dead tissue, as well as distorted leaf growth. It is most likely to occur in alkaline soils after long hot, dry spells. Beets can suffer from “zoning,” (white rings in the roots), if there are acute weather fluctuations.
Young Cylindra beets in early May. Photo Pam Dawling
Sow beets whenever the soil is between 50°F (10°C) and 95°F (35°C), so long as you can keep the surface damp. With beets we do a single sowing in mid-March and more in early August. We are growing for fresh use, pickling and storage, but not bunch sales, so we don’t need to do frequent sowings. For a continuous supply of greens and baby beets, sow every 2 weeks from spring until 8 weeks before regular frosts usually occur, or about 10 weeks before a heavy freeze is expected.
We direct sow either dry beet seed, or some we have presoaked for 1-2 hours. Beet seed drowns easily: don’t use too much water or soak for too long. Sow 0.5″(1.2cm) deep in spring, deeper in hot summers, but never more than an inch (2.5cm) deep. We sow an inch (2.5 cm) apart in single rows 8-10” (20-25cm) apart. Others sow in bands 2-4″ (5-10cm) wide, at about 15 seeds/ft (2cm apart), with bands 12-18″ (30-45cm) apart. As for carrots, avoid soil crusting.
It is important to get good soil contact for the corky seedballs, so tamp or roll the rows after seeding. Keep the rows damp, by watering as needed for the 5-17 days they take to emerge. Beet seeds are actually seed balls (clusters of seeds) so each one you plant will produce several seedlings right next to each other. “Singling” the beets is an important step, and they will benefit from hoeing, thinning and weeding. Beets deal with weed pressure and crowding a lot better than carrots do, so if you have to choose which to weed, the carrots win! We thin in stages, so that at the second thinning, the baby beets can be used as a crop.
Detroit Dark Red beets , harvested, washed and trimmed. Photo Pam Dawling
For mature beets, allow each a minimum of 3” (7.5cm). The Cylindra beets can be left a bit closer, and will push themselves up out of the soil as they grow. Know and Grow Vegetables recommends establishing 5 plants per square foot (54 per square metre) for early beets. This translates to a final spacing of 4 x 7” (10 x 18cm). For maincrop beets, aim for 10-15 per square foot (107-161 per square metre.) For maximum total yields of small sized roots use a spacing of 1 x 12” (2.5 x 30cm).
This info about growing beets is excerpted from my book Sustainable Market Farming. See the book for more on pests and diseases, harvesting and storing, and seed saving.
In our climate, beets are one of the crops that can be sown in spring and again in early fall (actually August for beets here in central Virginia). See my August post Sowing beets, radishes and kale, transplanting cabbage.
See Root Crops in August for more about fall beets. Beets can be tricky to germinate in hot weather, but to get good storable-sized roots, we need to get them established by 8/20. (Two months before our average first frost.)
Root Crops to Harvest in Central Virginia in March
From storage, if we still have them, we can eat beets, carrots, celeriac, kohlrabi, parsnips, potatoes, rutabagas, sweet potatoes, and turnips.
As in January and February in central Virginia, there are no roots to harvest outdoors in March except parsnips, Jerusalem artichokes and horseradish. We do have horseradish, but not the others, but we don’t have a lot of demand for that.
We have had outdoor night temperatures of 12°F/-11°C and 11°F/-13°C. This winter we had some carrots outdoors over the winter. We harvested them and got 150 pounds from 400 row feet. Not a high yield but they do taste good! They are Danvers 126. The intended sowing date was August 14, but we didn’t get the seed in the ground until September 5.
A crate of overwintered Danvers 126 carrots
In the hoophouse our #4 radishes will get harvested during March. Our #5 radishes, sown 12/23, will then feed us until around April 7.
We still have some of our good size second hoophouse turnips until mid-March. We sowed those on October 25. The greens are a bit ragged now and less appetizing for cooking, although on cold rainy days, they make for more pleasant harvesting than any greens outdoors! Turnip greens (and Russian kale) are our last hoophouse greens to bolt, so we value them.We need to harvest the turnips to make space to transplant our hoophouse tomatoes in mid-March.
Other Root Crop Tasks in Central Virginia in March
Buy seed potatoes for June planting, and refrigerate them. Keep at 40-50°F (4.5-10°C) in the dark, until 6/1.
Test and condition sweet potatoes for 2 to 4 weeks at 75-85°F (24-29°C), 95% humidity if you are planning to grow your own sweet potato slips.
Sweet potato sprouting slips. Photo Pam Dawling
Special Root Crop Topic for March in Central Virginia: What makes vegetable crops bolt?
Green mizuna bolting in our hoophouse in mid April. Although the mizuna is bolting, the Scarlet Frills is hanging in there. Photo Pam Dawling
Bolting is the term for plants going to seed. Rather than grow more leaves and bigger roots, the plants develop stems, skinnier and fewer leaves, then flower buds, flowers and seeds.
The plants are switching their energy to survival of the species in the face of unsuitable conditions.
When a plant starts to bolt, it is usually a sign to expect a poor harvest. It is also an indication that the plant will decline in terms of flavor. Lettuce become bitter. As long as you can harvest leaves or roots that are not too woody, you can eat bolting plants. But they do become too tough and inedible at some point.
Crops inclined to bolt include arugula, basil, beets, brassicas (such as cabbage), carrots, celery, leeks, lettuce, onions, turnips and spinach.
Bolting is initiated by plant hormones called gibberellins.
Although bolting is usually seen on crops approaching maturity, it is initiated much earlier.
It’s a complex business, understanding the various triggers to bolting.
Stress factors, including changes in day length (usually an increase), high temperatures or low temperatures at particular stages in a plant’s growth cycle, plant size, plant type, root stress, and stresses such as insufficient water or minerals.
Increased day length: Bolting can happen when day length increases as summer approaches. This can be a problem if you planted your seeds too late in the spring. The extra hours of light trigger annual plants to run to seed.
High soil temperatures: As soil temperatures increase in summer, plants are triggered to begin seed and flower production. This isn’t a problem late in the crop’s life, after bountiful harvests. But, when spring has unusually hot weather or if you plant crops too late into the growing season, your crop may bolt before any harvests. Cool weather crops like lettuce and spinach will bolt in spells of hot dry weather.
Cold temperatures: A sudden cold snap in spring can signal to biennials (such as onions, leeks, beets and carrots) that “winter” has happened and it’s time to develop seeds for the next season. If you start these crops too early in the calendar year, you risk exposing young plants to cold weather, priming the plants to develop flower stems as soon as the weather warms up again.
Plant size:
Annual plants grow from seed, flower and set seed all in one year. That can be spring to winter or fall to summer. Annual crops are sensitive to daylength, and will start making flowers as the daylength (and temperature) increase. When an annual plant bolts, it’s the beginning of the end.
Biennial plants (onions, leeks, carrots, beets, and chard) grow big the first year, then seed the second year. They can initiate flowers in the first yea, due to unsettled weather early in the season. Bolting usually occurs after a prolonged cold spell, often during an immature stage. Cold nights, hot days and late frosts may also contribute to premature flowering.
Root stress: Bolting caused by root stress typically happens when you disturb a plant’s root system by transplanting, or if your plant runs out of growing space in a container that’s too small.
Stresses such as insufficient minerals or water: Healthy soil with plenty of nutrients and balanced moisture levels will encourage quick growth. Every grower should aim for this balance, especially those in hotter climates where it’s a race to plant leafy salads, cooking greens and root crops before the hot weather fights against you.
Collards bolting in late March.
Photo Pam Dawling
Next week I will provide information on avoiding, preventing and postponing bolting.
Commiseration and sympathy to ice-blasted farmers and gardeners
Visits to my website shot up over the weekend. People are checking out my Winter-Kill Temperatures of Cold-Hardy Vegetables as they are dealing with temperatures considerably colder than they ever expected for their region. I hope you can find some helpful information there while you triage your crops into “OK with these temperatures, can be left alone”/”might die, need help”/”will definitely die, no point in trying to save them”.
Q and A
Next a couple of questions that people left on the contact form, that I thought others might be interested in.
Q1. Is there an easy way to figure out what vegetables I can plant to maximize my space and yield. I am not sure if its my soil or sunlight availability in my backyard garden.
A. Most vegetables do need at least 6 hours a day of sunlight, so as we get closer to spring, assess various spots in your backyard. Maximizing use of the space includes careful choice of plant spacing, but also following one crop with another, or squeezing crops in between others. There’s no quick answer. Search my site for Succession Planting, Crop Spacing, Choosing Crops.
Q2. I am currently looking for Onion seeds or seedlings to purchase for approximately 1hector to plant. We based in the Free State Area.
A. South Africa? Sorry, I have no idea what is available where you are. 1 hectare is a huge area for onions, especially if you have never grown them before. Use transplants, not direct-seeded onions. Choose varieties adapted to your latitude, or else they may never grow big, or may not dry down and store well.
Flaming can be used for weed control, pest control, or crop termination.
Flame weeding can be used for carrots and beets before emergence. Photo Brittany Lewis
Our introduction to flame-weeding was via the first article I ever read in Growing for Market magazine. It was about flaming for pre-emergence weed control in carrots. It sounded like such an effective method that we bought a Red Dragon flamer and never looked back! I remember saying and writing that it worked so well it felt like cheating!
Our flamer
We use a handheld flamer attached to a propane cylinder that is in a wheelbarrow pushed by a second person behind the first. This person also acts as a “fire warden.” Some growers mount the propane on a backpack frame. Walking along the aisle between beds and wafting the wand diagonally back and forth across the bed takes about ten minutes for a 100′ (30 m) bed. Flame-weeding alone can reduce hand-weeding to one hour/100′ (30 m). Hand-weeding can be reduced to 6 minutes/100′ (30 m) by flame-weeding after using stale beds which have been hoed three or four times.
Stale seedbed flaming for weed control
In the stale seedbed technique, the bed is prepared and watered ahead of planting time and one or more flushes of weeds are germinated and flamed or hoed off. Flaming avoids bringing any new weed seeds to the surface. To sow large crop seeds into a seedbed that has already had the weeds removed (by flaming or other stale seedbed technique), you can use a stick seeder or easy-plant jab planter. Making furrows for small seeds will inevitably activate a few weed seeds along the rows.
Flame weeding, pre-emergence
Flame weeding a carrot bed. Photo Kati Falger
Carrots, beets and parsnips are ideal crops for pre-emergence flame-weeding. They do very poorly with competition, and grow more slowly than weeds, consuming lots of time hoeing, cultivating and hand weeding to get good yields. Flame weeding can change all that, with pre-emergence either as part of a stale seedbed technique, or post-sowing.
The latter method is to prepare the bed, sow the seeds, water, and then monitor carefully. The day before you expect the carrots to emerge, flame across the whole surface of the bed. Use a soil thermometer and the table here to figure out which day to flame.
Table of vegetable seed germination as a function of soil temperature
Days to Germinate
50F (10C)
59F (15C)
68F (20C)
77F (25C)
86F (30C)
95F (35C)
Carrots
17.3
10.1
6.9
6.2
6.0
8.6
Beets
16.7
9.7
6.2
5.0
4.5
4.6
We sow “indicator beets” with our carrots so that we know when to flame-weed them Photo Kathryn Simmons
People who use pre-emergence flame-weeding for carrots can use a few “indicator beet” seeds sown at one end of the bed to show when to flame. As soon as you see the red loops of the beet seedlings breaking the surface, flame the carrots. (But look for carrots too, just in case!) Beets are always a bit quicker than carrots in germinating. Note that beets are about half a day ahead of carrots at 50°F–68°F (10°C–20°C), but more than a day at 77°F–95°F (25°C–35°C). The challenge with carrots is to keep the soil surface damp until they come through. As an indicator for beet seeds, you can use a few radish seeds.
Another way to get an alarm call is to put a piece of glass over part of a row. The theory is that the soil under the glass will be warmer and the crop there will come up sooner than the rest. I tried this once, but the soil under the glass dried out, and those carrots came up later than the rest! Nowadays we have a “no glass in the garden” rule, for safety, so I use beets, the thermometer and the chart.
Potatoes can get impossible to hill when you’d like to if you have wet weather, and this is where flaming can save the day. Potatoes may be flamed at 6″–12″ (15–30 cm) tall, to kill weeds without damaging the potato plants. After that, flaming is not recommended.
Sweet corn can be flame-weeded after planting, either pre-emergence or, with care, after the crop is two inches (5 cm) tall, using a directed flame.
Onion and garlic crops can be flame-weeded when relatively mature. Flame-weeding can achieve as good results as hand-weeding using one-third of the labor. Flame-weeding can damage young plants (four or fewer leaves), so bide your time. Direct the flame at the base of the plants, in the morning, when the plants are turgid. This technique is for unmulched crops. Naturally, if you have used straw or hay mulch, flame-weeding is not such a smart idea!
Peanut seedlings can be slow to emerge, so pre-emergence flame-weeding may be helpful. The seedlings look somewhat like peas or clover. Because they grow slowly for the first 40 days, they will not thrive if you lose them in weeds (guess how I know?!).
Flaming for ending potato growth
Potato plants come to a natural end when the leaves die, after which no further growth can be induced in them. Once the tops die, the potato skins start to toughen up. If you are growing storage potatoes and are impatient for the end to come, you can mow off the tops or flame them, to start the skin-thickening process, which takes around two weeks. The potatoes are ready when you can rub two together without any obvious damage to the skins.
Flaming for pest control
Pest habitat includes all those half-wild edges and odd corners. You can reduce the pest count in these havens by mowing, hand weeding, or flaming. Be sure not to remove all the habitat for beneficial insects while you do this.
Colorado Potato beetle late stage larva Photo Pam Dawling
Colorado potato beetles can be tackled by flaming while the potatoes are less than eight inches (20 cm) tall, as an effective pest control measure. It won’t kill the potato plants. Choose a warm sunny day when the pests are at the top of the plants. Flaming can kill 90 percent of the adults and 30 percent of the egg masses, according to ATTRA.
Harvesting from bean plants with bad bean beetle damage. Photo Wren Vile
Mexican bean beetles can be killed by flaming after harvest for that planting is finished. Flaming will kill the plants too. We used to plant six or seven successions of beans, every two weeks, then flame the old plants when the pest count got too high, and move on to a newer planting. Nowadays we buy the Pediobius parasitic wasp to deal with the MBB, and we can sow beans less often and harvest them for longer.
Flaming trap crops
Young turnips (with flea beetles!) in need of thinning for cooking greens. Photo Pam Dawling
Flea beetles can be lured by a row of mustard greens. They like the pungent compounds in brassicas. Once you have lured the flea beetles you need to deal with them before you create a flea beetle breeding ground. Flaming the mustard plants is one possibility.
Striped cucumber beetle in squash flower. Photo Pam Dawling
Cucumber beetles have a preference for some particular squash varieties, which may be grown as a trap crop: Cocozelle summer squash, Seneca and Dark Green zucchini are all “cucumber beetle preferred”! When beetles accumulate in the trap crop, flame it or till it in.
Stink bugs: Russ Mizell has published a paper on trap cropping for native stink bugs in the South. He recommends buckwheat, triticale, sunflower, millet, field pea and sorghum. A succession of trap crops including these and others such as pumpkins, cowpeas and other small grains (which are most attractive in the milk or soft dough stage) could help. Flame the trap crops when the stink bug numbers in the trap crop build up.
Excerpted and adapted from Sustainable Market Farming
Repurposed stroller makes a fine flame weeder. Photo Sustainable Harvest Farm Kentucky
Root Crops to Plant in Central Virginia in February
We sow no root crops in our hoophouse in February. It’s too late for radishes or turnips. If you are in a place colder or darker than winter-hardiness subzone Zone 7a, with an average minimum temperature of 0° to 5° F (-18°C to -15°C), see Root Crops in January.
If the soil outdoors is dry enough and not frozen, we spread compost on the raised beds we plan to plant in February and March, and till in the compost. Root crops that we sow outdoors here in February include carrots #1 and turnips in mid-February, and carrots #2 and radishes in late February. It’s true not much growing happens in February, but it helps us if we are able to get some crops planted early, leaving us more capacity for other crops once those are in the ground. And if the soil isn’t dry enough, we just do those jobs as soon as we can. We would hate to miss an opportunity!
Carrot Bed Prep
One of our many carrot beds, looking good. Photo Kathryn Simmons
Carrots do very poorly with competition from weeds or too many other carrots. You can make use of the Stale Seedbed Technique, preparing the bed ahead of time, and flaming or hoeing one or more flushes of weeds as they germinate. I’ll do a separate blogpost on flame-weeding soon, as I have too much info to squeeze in here. It works so well, it feels like cheating!
Carrots are small seeds, needing a fine tilth (small soil particle size and good texture – not likely to crust or blow away).Good information on crop spacing for maximum yields, or biggest vegetables is in an out of print book, The Complete Know and Grow Vegetables by JKA Bleasdale, PJ Salter, and others. For maximum total yield of carrots, they recommend 1.5” x 6” (4 x 15cm). You get medium sized carrots. For early carrots go with 4 x 6” (10 x 15cm) to minimize competition and get rapid growth. If you want to have rows more than 6” (15cm) apart, calculate the area of these optimum spacings, then divide by your chosen row space. For example, if your rows are 12” (30cm) apart, the carrots can be as close as 0.75’ (2cm) if total yield is more important than individual size, or 2” (5cm) for fast early carrots. We do five rows in a 4 ft (1.2m) bed, so the rows are about 10” apart, with the outer rows 4” (10cm) from the bed edge.
Young Carrot Plants After Thinning. Photo Kathryn Simmons
Carrot Thinning and Weeding
Remember to thin carrots as soon as you can see them well enough to do so. We usually hoe between the rows first, then crawl along thinning and weeding. It does take time! But you won’t get good carrots without thinning, unless you either have a precision-seeder that drops one seed per inch, or pelleted seed which you can sow at one per inch. Precision seeders like the Jang are expensive, but worthwhile if you need to use it every week. Pelleted seed costs more than raw seed, and its big advantage is traded off for two other disadvantages: The soil has to be kept well-watered until germination or else the clay coating will imprison the seed forever, and the seed does not store for long – don’t keep any over for next year.
Greenhouse Root Crop Sowings for Transplants
The only root crops we ever transplant are celeriac and kohlrabi (a stem vegetable really, not a root). I have transplanted many things and I am skeptical of books saying this or that can’t be transplanted, but not beets or rutabagas, which I hear people transplant as soil blocks or plugs. So try it if you think it will help.
Celeriac
Flats of celeriac seedlings. Photo Kathryn Simmons
We have grown both Diamante (100 days from transplanting) and Large Smooth Prague (110d), and strongly prefer Diamante, as it seems to us to be more tolerant of warm weather, less prone to rot, and easier to clean. Several growers say that Diamante and Brilliant are virtually indistinguishable.
This crop likes rich soil with lots of organic matter, some shade from mid-day and afternoon sun, and ample water without sitting in waterlogged soil. We make sure to choose beds in a shadier part of the garden. Celeriac can rot if too damp, so keep it weeded and remove some of the lower leaves to improve airflow. A pH 5.8-6.7 is ideal. Celeriac can benefit from seaweed as a foliar spray, or side-dressing with compost during the long growing season.
Celeriac requires long steady growth, and the challenge is to prevent checks to growth. The Virginia climate is on the warm side for celeriac, it prefers cooler areas, but we have good success if we pay attention at a few critical times. Celeriac can tolerate frost quite well, so there is no hurry to harvest in the fall.
Sow seeds 1/8″(3mm) deep, and keep the soil surface moist. The minimum germination temperature is 40°F/5°C, and the optimal range 59–70°F/15-21°C. Germination is slow, typically 14 to 21 days, and it takes 10-12 weeks to grow to transplant size, so start in plenty of time. We sow in open flats, then spot out (prick out) into deeper flats. We sow February 10, which is about 10 weeks before our last frost date. Celeriac can be sown from 67 days before the last frost date to 184 days before the first fall frost date, but you don’t get large roots unless you have plenty of growing time.. If your climate includes long chilly springs, I’d suggest starting 12 weeks before the last frost date.
Emergence takes at least 12 days at 59°F/15°C and 7 days at 68°F/20°C. The ideal temperature is 68°F/20°C day, and 59°F/15°C at night. The fluctuating temperatures, with nights cooler than days by 9°F/5°C, help speed germination. Another factor when choosing germination temperature to aim for, is that at 59°F/15°C, only 40% of the seeds produce seedlings, compared to 97% at 68°F/20°C.
Celeriac should not be hardened off by reducing temperatures, as that can cause them to bolt. More than about 9 night temperatures below 55°F/12°C will cause bolting. Plants can have their watering reduced to help them get ready for the big outdoors. Use rowcovers if a cold spell arrives after you have planted them out, or if you know cold weather is likely to return. Falling apple blossom is a phenology sign that conditions are suitable.
Harvested kohlrabi, Early White Vienna and Early Purple Vienna. Photo McCune Porter
Kohlrabi is very easy to grow, treat it just like cabbage or kale.
It can be direct-seeded, but for an early crop, especially if you live in a climate like ours where spring turns into summer very quickly, use transplants. We don’t grow a lot, only 180 feet (55m) in total for 100 people. We also grow kohlrabi in the fall, transplanting bare root transplants from nursery seedbeds around August 3. We grow twice as much in fall as spring, because we can store them for winter.
We have grown both Early White Vienna and Early Purple Vienna. Growing both provides for pretty harvests. We sow February 8 at 4 seeds/inch (0.5 cm apart) in open seed flats, aiming to have the plants spotted out, hardened off and transplanted outdoors with rowcover on March 13. Fast work!
Root Crops to Harvest in Central Virginia in February
Hakurei turnips harvested late January. Photo Pam Dawling
As for January, in central Virginia, there are normally no roots that we could be harvesting outdoors in February except parsnips, Jerusalem artichokes and horseradish. We do have horseradish, but not the others. Of course, you can only dig up root crops if the ground is not frozen!
We have had outdoor night temperatures of 16°F/-9°C and 12°F/-11°C. This winter we have some carrots “growing” in the fresh air and some late-sown beets under rowcover. I don’t think we’ll get roots from the beets, but the leaves might make a nice change from brassicas as cooking greens.
In the hoophouse our radishes #3 (sown October 30) will come to an end by 2/1. Our #4 radishes will get harvested this month. Our #5 radishes, sown 12/23, will feed us from then until around April 7
We still have some of our first turnips (sown around October 13) until mid-February, and they have reached a really good size, thanks to early thinning. This month we can harvest the second sowing (October 25). We thinned turnips #2 in early January. They are looking good too.
Red Round turnips in our hoophouse in late January. Photo Pam Dawling
We have not yet needed to unroll our inner rowcovers in the hoophouse. We wait until we expect it to get down to 8°F (-13°C) outdoors, as we like to avoid extra work!
Other Root Crop Tasks in Central Virginia in February
Potatoes stored in crates in our root cellar. Photo Nina Gentle
Check stored vegetables
Stored crops need to be checked for decay at least once a month, preferably once a week now the days are getting longer and the temperatures will get warmer. From storage, we can eat beets, carrots, celeriac, kohlrabi, parsnips, potatoes, rutabagas, sweet potatoes, and turnips, if we grew them.
Special Root Crop Topic for February in Central Virginia
Wrap up the winter planning
Our garden planning wraps up by mid-February, with all the budgets, crew selection and shift decisions (afternoons in cold weather, mornings in hot weather –we’re mostly half-day gardeners, with one or two stalwart all-day workers)
Order summer cover crop seeds
Buckwheat cover crop in flower. Photo Pam Dawling
For early spring, if we find an area without a winter cover crop and we realize we won’t plant it with a vegetable crop for at least 8 weeks, we sow oats. They will smother weeds and add organic matter to the soil when you till them in.
If you have not already ordered summer cover crop seeds, this would be a good time to do so. Cover crops suppress weeds, add organic matter, feed the organisms in the soil and attract beneficial insects, birds and amphibians to feed and reproduce. Biodiversity encourages ecological balance that can help reduce plant diseases and pest attacks. Have a goal of No Bare Soil. Seek out odd spaces to fill with cover crops.
Once frosts are past, buckwheat is an easy cover crop. Its flowers attract beneficial insects, and it is a very manageable (not too tall) fast-growing crop. Buckwheat can be in and under in a month.
Just as fast is mustard, but we don’t grow that because it’s a brassica and we grow a lot of brassica food crops. Keeping a good crop rotation is important to us. Also we have harlequin bugs and we don’t want to feed them year round.
Sorghum-sudangrass hybrid is a fantastic, huge warm weather grass type cover crop, but don’t grow it if you have only a lawnmower, a scythe or a nylon line weed whip to cut it down! For smaller scale gardens, choose Japanese millet.
Soybeans, southern peas and sunn hemp are easy legume cover crops for warm weather, providing nitrogen for the next crop.
Cover cropping is a big topic. See my book Sustainable Market Farming for more. Here I’m just pointing you in the right direction enough to order seeds soon. You can read up more later.
No Root Crops to Plant in Central Virginia in January!
Closing rowcovers after a winter spinach harvest. Photo Wren Vile
There is nothing, absolutely nothing, in the way of root crops that we sow outdoors here in January. Nor are there any root crops to sow in the greenhouse. Most root crops do not transplant well, as the replanting does too much damage to the taproot. Some exceptions are celeriac and kohlrabi (a stem vegetable more than a root, although I do tend to lump it in with root crops.) I have heard beets can be transplanted, especially if in soil blocks or plugs, and I’ve even heard of people up north transplanting plugs of rutabagas. I tend to be skeptical of books saying this or that can’t be transplanted, as I have transplanted many things. But not yet rutabagas or beets. I did roll my eyes when I heard someone propose transplanting mini-soil-blocks of carrots, using a pair of tongs made with popsicle sticks!
We are in winter-hardiness sub-zone Zone 7a, with an average minimum temperature of 0° to 5° F (-18°C to -15°C).
An Easter Egg radish in the hoophouse in January. Photo Pam Dawling
Around January 26, we sow our last hoophouse radishes (sowing #6), Easter Egg, and White Icicle. This is our absolute last worthwhile sowing date. They will be ready for harvest from mid-March to mid-April, but if the weather is warm, or we fail to open the doors when we should, they will bolt before we get roots.
Our hoophouse radish sowing dates are 9/7, 9/30, 10/28, 11/22, 12/20, 1/27. Note that the sowing intervals are 23, 28, 25, 28, 38 days. The interval is much longer in December-January, as the rate of growth is so slow. There really is no point in sowing closer to the #5 sowing date, as the #6 will catch up in the warming days of late February and early March. The daylength is also increasing a lot by then, too.
If your hoophouse planting plans exceed the space you have, simply tweaking to a less frequent new harvest start could free up space to grow something else. Also consider a gap in radish supply, if other crops could make better use of the space. See Root Crops in September for more about our succession of hoophouse radish sowing dates.
In our double-layer hoophouse, turnips (and many cooking greens) can survive a hoophouse air temperature of 10.4°F (-12°C) without rowcover, -2.2°F (-19°C) with thick rowcover (1.25oz Typar/Xavan).
January photo of radishes sown in our hoophouse at the end of November. Photo Pam Dawling
Root Crops to Harvest in Central Virginia in January
In central Virginia, there are normally no roots that we could be harvesting outdoors in January except parsnips, Jerusalem artichokes and horseradish. The months with R in them are the horseradish harvest months. September to April have R in them, and the summer months do not!
We have already had outdoor night temperatures of 16°F/-9°C and 18°F/-8°C. Until temperatures drop 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, rutabagas and rowcovered turnips. Covered beets, covered winter radish are OK down to 10°F (-12°C). This is too chancy for us! We like to gather our root crops in and have them safely stored.
We store our root crops washed, in perforated plastic bags, in a walk-in cooler. Root cellars and cool basements are also possible storage sites, and in the past, I stored root crops in boxes of damp sand or woodash.
In the hoophouse we can normally harvest radishes #3 (sown October 30) all through January, from 12/15 to 2/1. This winter I notice we have already harvested most of them (1/6). We harvest our first turnips (sown around October 13) by pulling out the biggest from January 5 (or even late December), until mid-February, by which time we can have made a start on the second sowing (October 25). We thin the second sowing in early January or late December.
Young midwinter turnips in our hoophouse. photo Pam Dawling
Other Root Crop Tasks in Central Virginia in January
Check stored vegetables
From storage, we can eat beets, carrots, celeriac, kohlrabi, parsnips, potatoes, rutabagas, sweet potatoes, and turnips, if we grew them. Stored crops need to be checked for decay at least once a month.
Rolls of rowcover in our hoophouse ready to pull over the beds on cold nights. Photo Wren Vile
Inner tunnels in the hoophouse for cold nights
As noted above, inner rowcovers can make a big improvement to nighttime air temperatures in a hoophouse. We are fortunate to have a climate in central Virginia that means we don’t need inner covers most of the time. We watch the forecast and if we think it will drop to 8°F (-13°C) outdoors, we pull over the rowcovers. For winter crops we don’t use hoops. We have separate lengths of rowcover for each bed. Some people prefer a single large sheet. We find we can set the roll of rowcover at one end of the bed and simply walk with the free end down to the far end of the bed, leaving only a little bit of tweaking to get everything covered.
In the morning, if we feel pretty sure we’ll need the rowcovers again, we just pull the covers into the aisles, leaving every other path free to walk in. If we think we won’t need the rowcovers the next night we roll them up, giving us more space to work, and lengthening the lifespan of the rowcover by not exposing it to much sunlight.
Special Root Crop Topic for January in Central Virginia
Garden Plans Part Two
This garden planning task is not just about root crops. We had our Crop Review in November, and then inventoried our leftover seeds, planned what to grow for next year, and ordered our seeds. See Preparing to order seeds, if you haven’t sent in your orders yet.
We have made our garden maps, and specific plans for important crops with either lots of varieties (tomatoes), lots of sowings (sweet corn) or some combination (lettuce, broccoli and cabbage).
One task we need to complete by mid-January is to prepare our greenhouse seedlings schedule, because here we start sowings in mid-late January. We also tidy up the greenhouse (currently growing lettuce) and test, repair or replace vital equipment (like a seedling heating mat) and supplies like Bt and cover crops seeds.
Tomato seedlings (for our hoophouse) on a heat mat in our greenhouse in February. Photo Pam Dawling
Another January task is to prepare a new Field Planting Schedule, or Outdoor Planting Schedule, as we call it here to distinguish it from our hoophouse schedule and our seedlings schedule. This is a list in date order of what to sow or transplant, how long the rows are, the space between rows, the space between plants (for transplants) and where to plant.
We also plan crops that will go in our raised beds from January to July. We plan the second part of the year in June, giving ourselves more flexibility.
Our garden planning wraps up by mid-February, with all the budgets, crew selection and shift decisions (afternoons in cold weather, mornings in hot weather – we’re mostly half-day gardeners, with one or two stalwart all-day workers)
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 Octoberfor 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
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
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