Getting ready for frost and colder weather

 

Eat-All Greens rows with frost in December. October and part of November are still productive growing weeks in central Virginia. Photo Bridget Aleshire

Gardening does not end with the first frost! We will work our way from clearing the least hardy crops to those we can leave outside all winter. See our table Winter Kill Temperatures of Cold-Hardy Vegetables. We will harvest or cover all the frost-tender crops, make a last harvest of rhubarb (the stems are hardy to 22°F (-6°C)) and hoop and rowcover the last outdoor lettuce. Our June-planted potatoes will be our last big harvest for the year.

We pull up the biggest Purple Top turnips and Cylindra beets, leaving the others a bit more room to size up before their killing temperature of 12°F (-11°C). Any day now, we’ll start harvesting fall leeks (King Richard and Lincoln), keeping the winter-hardy ones (Tadorna) for the winter.

DIY weather-forecasting

I recommend learning your local weather patterns by keeping records and watching what happens. Here’s what I’ve learned about ours:

Our mid-Atlantic climate is controlled by three weather systems,

  • mainly by moisture from the Gulf of Mexico,
  • the Bermuda High Pressure area in summer,
  • and recurrent waves of cold Canadian air in winter.
Beds after rain, Photo Wren Vile

Rain (statistically fairly evenly distributed throughout the year in our county) has slight peaks in January, February and March, and again in early June and August.

Some parts of our area can experience long periods of drought. September-November is the drier season but it’s also the hurricane season, so the net result is very variable.

We use Wunderground.com  but subtract 5F° from their forecast night lows for our nearest town, and mentally downgrade the chance of rain by 10%, as rain often passes us by as it scoots along the river valley north of us.

Blackberry leaf with frost.
Photo by Ezra Freeman

Our average first frost date is October 14. Actually from our own records it has averaged 10/20 (13 years of our own records). So it’s time to start thinking about frost. It’s good to be prepared.

According to Dave’s Garden in Louisa County where I live, the threshold of 36°F (2°C) has a 50% likelihood on Oct 3; the 32°F (0°C) threshold has a 50% likelihood by Oct 13 and the 28°F (-2°C) threshold is as likely as unlikely by Oct 27. The 90% chances occur by Oct 14, Oct 28 and Nov 12 respectively.

Another great website for local weather info is WeatherSpark.

Now that climate change is here, it pays to be ready for weather different from what we have experienced previously. Keeping records helps, as does having good thermometers for air and soil.

Four Ranges of Cold-Hardy Crops for Harvest at Various Stages of Winter

This simple model helps reduce confusion and set priorities

1. Crops to harvest before cold fall weather (32°-25°F) and store indoors:

Michihili Chinese Cabbage. Photo Southern Exposure Seed Exchange

Chicory for chicons or heads; crosnes/Chinese artichokes, dry beans,  Chinese cabbage, peanuts, “White” Peruvian potatoes at 32°F (0°C) approximately, pumpkins, seed crops, sweet potatoes at 50°F (10°C), winter squash.

2. Crops to keep alive in the ground into winter to 22°-15°F (-6°C to -9°C), then harvest.

Bucket of freshly harvested Detroit Dark Red beets for storage.
Photo Pam Dawling

Store: Beets before 15-20°F (-9.5 to -7°C), cabbage, carrots before 12° F (-11°C), celeriac before 20°F (-7°C), kohlrabi before 15°F (-9.5°C), winter radish including daikon before 20°F (-7°C), rutabagas, turnips before 20°F (-7°C).

Use soon: Asian greens, broccoli, cabbage, chard, lettuce, radishes

3. Hardy crops to store in the ground and harvest during the winter.

Using a sturdy digging fork to harvest leeks in December.
Photo Pam Dawling

In zone 7, such crops need to be hardy to 0°-10°F (-17.8°C to -12.3°C): Collards, horseradish, Jerusalem artichokes, kale, leeks, parsnips, scallions, spinach.

4. Overwinter crops for spring harvests before the main season.

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

In zone 7, they need to be hardy to 0°-10°F (-17.8°C to -12.3°C): Cabbage, carrots, chard, collards, garlic and garlic scallions, kale, multiplier onions (potato onions), scallions, spinach.

Frost is more likely at Twin Oaks if:

  • The date is after 10/14 (or before 4/30).
  • The daytime high temperature was less than 70°F (21°C).
  • The sky is clear.
  • The temperature at sunset is less than 50°F (10°C).
  • The dew point forecast is low, close to freezing. Frost is unlikely if the dew point is 43°F or more.
  • The Wunderground 3.30pm forecast low for Louisa Northside is 37°F (3°C) or less.
  • The soil is dry and cool.
  • The moon is full or new.
  • There is little or no breeze, although if temperatures are falling fast, the wind is from NW and the sky is clear, then polar air may be moving in, and we’ll get a hard freeze.
Ice on the pond.
Credit Ezra Freeman

Frost Alert Card

For just this time of year, we keep a Frost Alert Card reminding us which crops to pay attention to if a frost threatens. We check the forecast online at 3.30 pm (we find that’s late enough to be fairly accurate about night temperatures and early enough to give us time to get vulnerable crops covered).

The big decision is the triage of harvest/cover/let go. Our list is not just crops that will die with the first frost but also ones that will soon need covering as temperatures decrease.

  • Cover lettuce, zucchini, summer squash, cucumbers, beans, Chinese cabbage, pak choy, lettuce and celery.
  • Harvest crops listed above that can’t or won’t be covered.
  • Harvest all ripe tomatoes, eggplant, corn, limas, cowpeas, okra, melons.
  • Harvest peppers facing the open sky, regardless of color. (Often only the top of the plant will get frosted).
  • Check winter squash and harvest any very exposed squash.
  • Set up sprinklers for the night, on tomatoes, peppers and a cluster of beds with high value crops.
Peppers that are protected by leaves can survive a light frost. Photo Pam Dawling

We really like this pepper strategy we have developed: by picking just the peppers exposed to the sky, we reduce the immediate workload (and the immediate pile up of peppers in the cooler!) and we often get a couple of milder weeks after the first frost before the next. By then the top layer of leaves that got frosted the first time will have died and a whole new layer of peppers will be exposed and need harvesting. This way we get fewer peppers at once, and a higher percentage of ripe peppers, which have so much more flavor.

Our overhead sprinkler strategy is useful if a frost is coming early when we still have many tomatoes we’d like to vine-ripen. Keep the sprinkler running until the sun is shining on the plant sin the morning, or the sir temperature is above freezing again. The constant supply of water during the night does two things. First water gives off heat as it freezes. Yes, really. It’s easier to understand ice taking in heat to melt, but the flip side is that water gives off heat as it freezes. This latent heat of freezing helps warm the crops. And if ice does form, the shell of ice around the plants stops more cold damage happening.

Frost Alert List

Task

Crop

Notes

 

Harvest all edible

Asparagus beans

 

Harvest all edible

Eggplant

 

Harvest all edible

Okra

 

Harvest all edible

Tomatoes

Including green ones

Harvest all edible

Peppers exposed to the sky

 

Harvest all edible

West Indian gherkins

 

Harvest all edible

Pickling cucumbers

 

Harvest all edible

Corn

 

Harvest all edible

Beans #4, 5, 6, then cover

Uncover once mild again

 

 

 

Thick row cover

Squash

Spring hoops or none. Ditto

Thick row cover

Slicing cucumbers

Spring hoops or none. Ditto

Thick row cover

Celery

Double hoops – leave covered

Thick row cover

Last lettuce bed

Double hoops – leave covered

Set sprinklers

Slicer tomatoes

Overnight from before 32F till after sun shines on plants

Set sprinklers

Roma paste tomatoes and peppers

Ditto

Set sprinklers

Other vulnerable raised bed crops

Ditto

Sun Gold cherry tomatoes. Pick the green and the ripe ones before a frost.
Photo Pan Dawling

Cold Weather Crop Protection

  1. Rowcover – thick 1.25 oz rowcover gives about 6F (3.3C) degrees of frost protection. Use hoops.
  2. Low tunnels and Quick Hoops are wider version of using rowcover. They need the edges weighting down. Best for climates where the crops are being stored in the ground until spring, when they start growing again. Less useful in climates like ours which have very variable winter temperatures, and are warm enough that we realistically expect to harvest during the winter, not just before and after.
  3. Caterpillar tunnels – 2 beds plus 1 path, tall enough to walk in. Rope holds cover in place, no sandbags.
  4. High tunnels (= hoophouses), single or double layer. Double layer gives 8F (4.5C) degrees of protection, plus plants can survive 14F/8C colder than they can outside, without extra rowcover; at least 21F/12C colder than outside with thick rowcover. Leafy crops are not weather-beaten. We strongly believe in two layers of plastic and no inner tunnels (rowcovers) unless the night will be 8°F (-13°C) or colder outdoors.

Hoophouse Notes

Salad greens in a hoophouse in zone 7 can survive nights with outdoor lows of 14°F (-10°C). A test year: Lettuce, Mizuna, Turnips, Russian kales, Senposai, Tyee spinach, Tatsoi, Yukina Savoy survived a hoophouse temperature of 10.4°F (-12°C) without rowcover, -2.2°F (-19°C) with. Brite Lights chard got frozen leaf stems.

Rolls of rowcover in our hoophouse ready to pull over the beds on very cold nights.
Photo Wren Vile

Other Posts on These Topics

10/18/16 Getting Ready for Frost

10/21/19 Preparing for Frost and Cold Weather

10/19/20 Harvest and Maturity Indicators in Vegetable Harvests.

10/16/18 Season Extension and Frost Preparations

Workhorse Crops for August

Crimson Sweet Virginia Select watermelon.
Credit Southern Exposure Seed Exchange

Workhorse Crops for August

I’m back again with my series of 14 Workhorse Crops (including two pairs) to focus on monthly until April 2022: These are crops that we can rely on under a wide range of conditions. Some Workhorse Crops are easy to grow, some pump out lots of food, some are “insurance crops”, some are especially profitable (for those growing for market), and watermelons are more of a circus pony than a workhorse!

I hope this series will help you become more efficient, productive and profitable (if selling) as your lives resettle. Maybe you are not at home as much as last year, but you’ve learned to deeply appreciate growing your own food.  So you need to choose less time-consuming crops and growing methods. You can use the search box to find previous month’s entries, such as July.

Workhorse Crops to Plant in August

Young Farao cabbage, a good fast-growing variety.
Photo Pam Dawling

In August here in central Virginia, the heat is still oppressive, but the day-length is definitely getting shorter. We and our crops have a longer night in which to recover for the next hot day. I remember the year I realized we just had to do some of our broccoli transplanting in the late afternoons, because the evenings no longer held enough daylight! Since those days we have reduced the size of our fall broccoli planting!

This month we will really need to plan for our fall and winter garden and execute our plan. There’s no making up for lost time in the fall! As the days get shorter and the temperatures (thankfully) start to drop, plants take longer to mature. A delay of a day or two in sowing leads to a delay of a week or two (or more) in the start of the harvest. Keep records and try several dates, especially if this is your first year, so you can fine tune your plan next year.

In August we can plant 8 of our 14 Workhorse crops in central Virginia.

Beans, zucchini and summer squash

These warm-weather crops get their absolute last chance before the season gets too cold. We sow our last bush green beans 8/1-8/3, and zucchini, summer squash and cucumbers by 8/5 at the latest. If you are in a colder climate than ours, with a first frost earlier than our October 14 average, your last sowings of beans, zucchini, summer squash and cucumbers were in July. It’s too late for us to sow edamame or sweet corn. More on Last Chance Sowings in the Special Topic at the end.

Fall carrots.
Photo by Bridget Aleshire

Carrots

We also reach our Last Chance for carrots for the year. We usually make a huge sowing of carrots on August 4, as our storage crop for the winter. We need 1500 pounds of carrots to feed us through the whole winter (30 bags). We sow 4000 row feet (1220 m), usually on temporary beds where we grew garlic until June, followed by a round or two of buckwheat cover crop before preparing the beds for the carrots. It really pays with carrots to reduce the weed level. We mulch our garlic and weed it every month from February until we remove the mulch when we see scapes in mid-May. Few weeds grow in the three weeks before we harvest. Buckwheat is a fast growing summer cover crop that is a modest size and easy to manage. It flowers about 4 weeks after sowing, and the flowers attract many beneficial insects.

After sowing the carrots with our trusty EarthWay seeder, we keep the soil damp by nightly watering until we see the red hooped stems of our indicator beet seedlings emerging. Then we know it’s time to flameweed. It’s usually the fourth day after sowing the carrots. This dispatches any new weeds thinking of emerging. As soon as we can see well enough to do so, we hoe between the rows with our scuffle hoes (stirrup hoes). Once the carrots are 1” (2.5 cm) tall, we hand weed, cultivate with claws (to kill weeds that haven’t even emerged yet) and thin to 1” (2.5 cm). Later we thin to 3” (7.5 cm) and weed again. That’s a September task.

Cabbage and Collards:

For the cool weather greens we are in our second season for the year. August is too late for us to start broccoli, collards or cabbage. In July and August we transplant the starts we sowed in June and July. At this time of year, we aim to transplant brassicas at four true leaves (3-4 weeks after sowing). In hot weather, use younger transplants than you would in spring, because larger plants wilt from high transpiration losses. If we find ourselves transplanting bigger plants, we remove a couple of the older leaves to reduce these losses.

To avoid flea beetles and harlequin bugs, we cover the nursery seedbeds until we transplant, and then cover the transplants for four weeks, until the plants are big enough to survive bug bites. Nets are better than rowcover in hot weather, as airflow is better and heating is less. This might require a bit of re-planning to get best value from the netting. For example – instead of planting the rows an equal distance apart, plant two rows closer than before, and then have wider aisles. One width of netting can cover two rows of brassicas, each with their own (offset) hoops.

Transplant seedlings under insect netting outdoors.
Photo Pam Dawling

Dubois Agrinovation has a range of ProtekNet Insect Exclusion Netting, made of clear high-density knitted polyamide (lighter weights), polypropylene/olefin (mid-weight) or polyethylene (heavy weights), with UV resistance. Be sure to buy the size mesh that keeps out the pest you are guarding against. See the Dimensions and Specifications tab on their website. We have bought the 0.0335″ x 0.0335″ (0.85 mm x 0.85 mm) mesh (against harlequin bugs) and the 0.0138″ x 0.0138″ (0.35 mm x 0.35 mm) mesh against flea beetles. Pieces can be sewn together, or Dubois will join them with zippers. See the Details tab for the insects excluded by each particular mesh. Light transmission is 88-93%. Ours have lasted many years, longer than rowcover. Use hoops to hold the mesh above the plants so insects can’t lay eggs through the holes. Purple Mountain Organics sell the whole range in full rolls, and the 25 g in 6.9’ x 33’. Johnny’s Seeds sells 6.9’ x 328’ 25 g “Thrips Net”. Compare shipping charges as well as netting price.

Two weeks after transplanting, we till or wheelhoe between the rows and hoe around the plants, removing the minimum amount of netting at any one time that we have to. Four weeks after transplanting, we remove the netting entirely, and hoe and till again. This time we undersow with a mix of clovers to be a long-term cover crop.

Kale:

We sow 6 beds of kale, two every 6 days, (8/4, 8/10, 8/16, and if we need to resow, 8/24) until we succeed in getting enough established. We focus our attention on the two newly sown beds, watering daily as needed, until the seedlings emerge.

We want a lot of kale, and there isn’t time to transplant it all. We grow Vates dwarf Scotch curled, the most cold-hardy variety I’ve found. It isn’t huge – we plant 4 rows per bed 10″ (25 cm) apart. We’re looking at 6x4x90 plants.

We carefully thin, leaving one plant every foot (30 cm). Often we’ll get patchy emergence and we use the carefully dug thinnings to fill gaps and to plant other beds, at the same plant spacing. Our mixed direct-sow/transplant method allows for the fact of patchy germination, and requires less watering than if direct sowing it all at once. If your climate is a colder zone than ours, you would start sowing kale in July. We cover the beds with Proteknet.

Kale make some growth whenever the temperature is above about 40°F (5°C), which happens in our winters on many days, making this a valuable winter crop.

ProtekNet over kale transplants in August.
Photo by Bridget Aleshire

Chard: Swiss chard can be sown here in July or August, for a good fall harvest, with the option of overwintering under rowcover. It grows small leaves after only 35 days, and full-size leaves after 50 days. Chard is not eaten by flea beetles, and does not have problems germinating in hot weather like spinach does. Chard is our poster-child insurance crop! So easy! So productive!

Workhorse Crops to Harvest in August

Eleven of our 14 workhorse crops can be harvested in August!

Beans­ can be harvested here from late June until the first frost (or later if we cover the beds with rowcover when a frost threatens).

Cabbage planted in the spring is ready here from late May until mid-July, or a little later if we planted late-maturing varieties. When I was a new gardener I thought “early varieties” were to be planted early, and “late varieties” to be planted later. It would be clearer if they were labeled “fast” and “slow”! For the second half of the year, late varieties need to be sown earlier than early varieties to get a harvestable crop before it gets too cold. Be sure to check and compare the days to maturity numbers for the varieties you are growing.

We store enough spring cabbage to feed us until we start harvesting fall cabbage.  It’s about a 50lb (25 k) bag a week. Fall planted cabbage won’t be ready until September 25.

Danvers Half Long carrot, a good workhorse variety!
Photo Southern Exposure Seed Exchange

Carrots: After May we hope not to need to sow more carrots until the beginning of August, because carrots grown in hot weather don’t taste sweet and can even be soapy. But home-grown hot weather carrots are still better than industrial carrots from thousands of miles away. This year we finished harvesting our spring carrots in July and stored them in the walk-in cooler.

If we have not grown enough carrots in the spring, we sow in June, or July if we must. When we do sow in June and July, those carrots are ready about 2-3 months after sowing (less time in warm weather, longer as the weather starts to cool in the fall)

Chard can be harvested whenever you want some. Just snap or cut off some outer leaves and stand them in a bucket with a little water (or if your cooler isn’t as big as ours, put them in a loose plastic bag in your fridge) until you cook them. For sustainable harvesting levels, we use our standard leafy green mnemonic “8 for later” meaning that we make sure to leave at least eight of the inner leaves on each plant, as we harvest the outer leaves. With chard, we can take a couple more than this, but we don’t want to exhaust our workhorses!

Young Bright Lights chard.
Photo Pam Dawling

Chard is biennial, and will not bolt the first year (unless stressed by lack of water).  Red chards bolt more easily than the green ones, presumably red crops are a bit stressed already, as they are short of chlorophyll, compared to the green ones, making photosynthesis harder work.

To overwinter chard in our climate, we cover the bed with rowcover on hoops. We can continue to make harvests into early winter. The mulch and rowcover help keep warmth in the soil, which keeps the crop growing.

Ruby chard.
Photo Kathryn Simmons

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). If you want to overwinter chard in a climate colder than those temperatures, you can make a heavy harvest just before the weather turns seriously cold. This leaves the growing points of the plants alive. Cover the whole bed with thick straw or hay and wait for spring.

Fordhook Giant is a very reliable summer leafy green.
Photo Pam Dawling

Potatoes, if planted in April would be harvested in August here. We can plant potatoes between mid-March and mid-June, leading to harvests in July-October. It’s as important not to leave potatoes baking in the sun as it is to protect them from frost, both when planting and when harvesting. Read more about potato harvest here.

Sweet Corn harvest is well underway. Usually we start sowing as early as possible and hope to start harvesting on 4th July. Sweet corn will be ready to harvest about three weeks after the first silks appear. This year we are later, but it’s just as delicious. We harvest 3 days a week, which gives us a nice amount from our 1050-1325 ft (320-400 m) plantings to feed our community. Some growers say you should harvest daily, but we find every other day is often enough. We are able to rush our sweet corn straight to the cooler, and it doesn’t have to travel after that, so we enjoy very fresh corn. Be sure to shade your corn after harvest and get it cooled as soon as possible, as the flavor deteriorates if it sits around.

Silver Queen nearly ready to pick
Photo Kathryn Simmons

Determining sweet corn maturity can be hard for new growers. Corn is ready when the silks become brown and dry. If the silks are not brown, just walk on by! If they are brown, and the ears are plump and filled to the end with kernels, take a closer look. Mature ears stand away from the stalks. This is called “flagging”. If you are still unsure, and don’t want to make too many mistakes, slit the husks at the side of the ear with your thumb nails and look at the kernels. (Don’t puncture the husks on the top of the ear as the dew and a million tiny beetles will get in and make a mess.) They should be a bit squarish and tight packed, not round and pearly with spaces between them. An opaque, milky juice will seep out of punctured kernels. If your sample ear wasn’t ready, push the husks closed over the cur and wait a few days.

Jubilee tomato in our hoophouse.
Photo Pam Dawling

Tomatoes are ripening fast outdoors now. Wait for the leaves to dry from rain or dew, before touching the plants, to minimize the spread of fungal diseases. Lightly press the bottom of the tomato to make sure it is soft enough to be fully ripe. Snap the tomato off at the knuckle, so that the plant gets the signal the fruit has gone, and will ripen more. We pop off the green calyx and set the tomatoes in plastic crates that fit two or three layers of fruit. It’s always tempting to include cracked ones, but they quickly turn nasty, so only do that if you are going to sort them promptly and process the damaged ones.

Watermelon harvest is starting. Determining ripeness is both art and science, and it’s worth getting good at it, as harvested watermelons don’t ripen further after harvest. An unripe watermelon is a sad waste.

Crimson Sweet watermelon
Photo Nina Gentle

The first step is to look at your sowing date and the days to maturity for the variety you’re growing. If it’s too soon for them to be ready, don’t tempt yourself by looking! If the dates are auspicious, the next step is to look at a big melon and find the curly little tendril that grows from the vine where the melon is attached (but on the opposite side of the vine). It must be brown and dry. If not, leave the melon untouched!

If it is brown, you can slap the melon and listen. The sound should be like thumping your chest, not your head or your belly! If that seems to indicate ripeness, we have one last check, that works for Crimson Sweet. I’m not completely sure it works for all varieties, although I think it should. Stand astride the melon, bend and put your flat hands, heel to heel, over the width of the melon. Pause and ensure silence (if you have coworkers) and then press down firmly with quite a bit of weight. If the melon is ripe, you will hear and feel a scrunch, as the ripe watermelon flesh splits inside the melon. Then you know you have a really good one. Rural legend says this test only works once, so don’t practice, just do it for real!

Cut the melon stem and gently lift and set the melon down in the cart, truck or at the side of the patch. I know some crews throw the melons from one person to another, but Crimson Sweets are too big, in my opinion.

Note that these rules apply to watermelons, not to any other type of melon.

Golden Glory zucchini.
Photo Pam Dawling

Zucchini and summer squash in our climate need harvesting every day, if we are going to avoid blimps. Summer squash can be twisted off the plants, but zucchini need to be cut. The hairs on the leaves, combined with sweat, can cause unpleasant itchiness. Wear long sleeves or make special sleeves for this job that are not attached to any particular shirt. Make a casing and insert elastic around the top edge (and the bottom, if there are no cuffs). These sleeves can be bought, but everyone probably has an old shirt and could make their own.

We harvest every day to the fall frost (or beyond if we remember to cover that last planting with rowcover on chilly nights.).

From storage: spring cabbage, carrots and potatoes.

Workhorse Crops Special Topics for August:

Newly emerged beans (in rather dry soil).
Photo Pam Dawling

Formula to Calculate Last Planting Date for Warm Weather Crops

To calculate the last worthwhile sowing date for warm weather crops, add the number of days to maturity and the length of your desired harvest period, and subtract this number from your average first frost date. Using yellow squash as an example:

  • Number of days from seeding to harvest                                           50
  • Desired length of the harvest period                                                    21
  • 14 days to allow for the slowing rate of growth in the fall           14
  • 14 days to allow for an early frost (but we have rowcover)           0
  • Days before the first frost = total of these                                        = 85
  • Last date for sowing, with October 14 first frost date                  = July 21

But by throwing rowcover over the last planting during cold spells, we effectively extend the growing season by 2 weeks, and we can sow our last planting of squash on Aug 5.

Morris Heading Collards.
Photo Kathryn Simmons

Last Chance Sowings: Fast Fall Crops for When Time is Short

Some crops mature in 60 days or less. These are mostly greens and fast-growing root vegetables. They are useful to fill space and time before you plant winter cover crops.

Ready in 30–35 days:

  • arugula, frilly mustards, kale, radishes.
  • some Asian greens: Komatsuna, Maruba Santoh, mizuna, Tokyo Bekana.
  • spinach, chard, salad greens (lettuce, endives, chicories), winter purslane.

Ready in 35–45 days:

  • corn salad, land cress, sorrel, parsley, chervil
  • More Asian greens: Senposai, tatsoi, Yukina Savoy

Ready in 45–60 days:

  • beets, Napa cabbage, small cabbages (Farao or Early Jersey Wakefield), collards, kohlrabi, pak choy, turnips

Use the chart below to figure out your last chance to sow crops with various days to maturity

Sowing dates for fall crops with various days to maturity

Days to   For harvest For harvest For harvest
Maturity   mid-Sept- late Sept- from  
    mid Oct mid-Oct mid-Oct
30d   27-Jul 16-Aug 31-Aug
40d   17-Jul 6-Aug 21-Aug
50d   7-Jul 27-Jul 11-Aug
60d   27-Jun 17-Jul 1-Aug
70d   17-Jun 7-Jul 22-Jul

For example, Early Purple Vienna Kohlrabi takes only 60 days from sowing to harvest in spring. Allow for the slowing rate of growth in fall (unless you will use rowcover). Kohlrabi is hardy to maybe 15°F (-9.4°C). When is it likely to get that cold? Not before the beginning of November here, so counting back 31 days in October, plus 30 in September, plus 31 in August – that’s 92 days already, more than enough. We could sow kohlrabi in early August and get a crop at the end of October.

A September sowing of kohlrabi. Too late for roots, we ate the greens.
Photo Bridget Aleshire

Vegetable Garden Tips

 

Young Yukina Savoy plants.
Photo Ethan Hirsh

My virtual workshop on Asian Greens 

is available from Mother Earth News Fairs Online here.

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

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Decoy Cabbage White Butterflies.
Photo Good Seed Co

Easy DIY Cabbage Butterfly Decoy!

The Good Seed Co blog posted this lovely idea for protecting brassicas from those white butterflies Pieris rapae. It’s based on the discovery that the butterfly is territorial. If it sees a slightly bigger competitor it flies away. I have not tested this system, but it sounds like an interesting and fun project that costs next to nothing.

http://goodseedco.net/blog/posts/cabbage-butterfly-decoy Posted 25th Jun, 2015 in On Our Mind by Robin Kelson

PageOfCabbageMoths_efile

Cut out paper decoy representations of the butterfly. Here’s a single page template you can download

We don’t have many cabbage butterflies  because we have both a predator – the paper wasp, and a parasite –  Cotesia glomerata, a parasitic wasp that lays its eggs in small (first instar) larvae of the Cabbage White Butterfly, or Imported Cabbage Worm (as we call it in the US). Cotesia larvae emerge from the caterpillars after 15-20 days and spin yellow or white cocoons on or near the host which dies when the wasps emerge. We often find clusters of these cocoons (about the size of cooked rice grains) on the underside of brassica leaves.

I learned from Bryan O’Hara in  No-Till Intensive Vegetable Culture that our friends, the Cotesia glomerata wasps that parasitize brassica caterpillars, and overwinter as pupal cocoons on the undersides of brassica leaves, will hatch out in spring on the very day the overwintered brassicas start to flower. The 20-50 day lifecycle needs brassica flowers, so don’t be in a hurry to cut down all your bolting greens! The flowers provide nectar for the adult wasps. The leaves, as we know, provide food for the caterpillars, which provide the host for the wasps to lay eggs in. The wasp larvae feed on the caterpillar until it dies, then pupate.

There’s an incredible National Geographic video of this cycle, showing parasitic wasp larvae swimming around inside a caterpillar, bursting out through its skin. The weirdest bit is that it is the dying caterpillar that spins the protective cocoons around the pupating larvae. And us who plant the brassicas that feed the caterpillars! Who is the farmer and who is farmed?

This video shows a paper wasp tackling a caterpillar.

This one shows Cotesia glomerata emerging

This one shows more about the parasitic Cotesia glomerata 


Savoy cabbage with frost. Savoys can take much colder temperatures than this!
Photo Lori Katz

Average First and Last Frost Dates

Harvest to Table has this helpful article:

Average First and Last Frost Dates for Cities, States, and Countries

Average frost dates – the last one in spring and the first one in the fall – are useful to know when planning your crops. Once you’ve calculated your planting out date for various crops, you can work back to set sowing dates for the crops you’ll transplant, and bed prep dates for every crop. You can also make a co-ordinated plan that paces the work and doesn’t have too much in any one week, or any while you plan to be on vacation. You can calculate your first sensible planting date for each crop, your last one and perhaps some in-between ones to keep up supplies throughout the season.

You can use your average first fall frost date to make sure you don’t plant frost-tender crops too late in the season when you have no hope of them maturing in time for a harvest. You can extrapolate beyond the frost date to figure out when to harvest the more hardy crops. See my Winter-Kill Temperatures chart for useful tips.

By looking at the number of frost-free days in your area you can see whether to grow long-season tender crops like watermelons, or whether it’s only worthwhile if you choose fast-maturing varieties.

The Harvest to Table website is a trove of clearly explained information.

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Soil thermometer with easy-to-spot backing in a bed of beets.
Photo Bridget Aleshire

Soil Temperatures

Average frosts are only averages. Actual frosts can sometimes happen two weeks either side of those dates. Frosts are only one particular temperature, and may not matter to the crop you’re planning for. Soil temperatures for germination and for planting are another important part of planning.

K-State Extension has a brief article on the importance of measuring your soil temperature.

The Empress of Dirt has a helpful list of Best Soil Temperatures for Sowing Vegetable Seeds, in alphabetical order by crop.

Harvest to Table also has a list, ranked by temperature, so you can see what you can plant this week.

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Scottish Climate Friendly Farming Video

Farmer Patrick Barbour, from Highland Perthshire, has won the search for Scotland’s climate friendly farming champion. Patrick’s innovative three-minute video entry, filmed at Mains of Fincastle, near Pitlochry stunningly illustrates the benefits of tree planting, species rich grassland, rotational grazing for cattle and sheep and stitching nitrogen fixing crops into pastures.  It is available to watch at: Next Generation Climate Change Competition

Patrick, Robert and Catherine Barbour of Mains of Fincastle, near Pitlochry
Photo The Scottish Farmer

What makes vegetable crops bolt and how can I stop it?

Hoophouse spinach in May. Back: bolting Renegade; Front: Escalade.
Photo Pam Dawling

What causes bolting?

 

This is an updated version of the section I included last week, followed by the all-important section on how to stop  or at least delay, plants from bolting.

Bolting is the term for plants going to seed. Rather than grow more leaves and bigger roots, the plants develop stems, fewer and skinnier leaves, then flowers and seeds. The plants are switching their energy to survival of the species in response to the 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. Lettuces 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.

Although bolting is usually seen on crops approaching maturity, it is initiated much earlier, by plant hormones called gibberellins. Bolting then can be triggered by one or more factors, sometimes acting in concert.

  •  ·         Increased day length: Bolting can happen (especially with annual crops) when day length increases as summer approaches. This can be a problem if you planted your seeds too late in the spring to get a harvest before the plants bolt.
  • ·         High soil temperatures: As soil temperatures increase in summer, annual 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.
Bolting lettuce in July
Photo Alexis Yamashita
  • ·         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: larger plants are more likely than small ones to bolt when a trigger such as cold temperatures strikes.
  • ·         Annual plants (basil, lettuce, melons, peas) 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. Many annuals are crops where we eat the fruit or seeds and bolting is not an issue.
Bolting Vates kale at the end of March
Photo Pam Dawling
  • ·         Biennial plants (beets, brassicas (broccoli, cabbage, kale, turnips etc), carrots, celery, chard, leeks, onions, spinach) grow big the first year, then seed the second year, if we still have them. Many biennial food crops are grown as cool weather annuals. Unsettled weather (cold nights, hot days, late frosts) early in the season can cause biennials to bolt. Bolting usually occurs after a prolonged cold spell, especially with immature plants. Brassicas started in cool conditions, and grown on in warmer conditions, are primed to bolt. Tatsoi, for example, bolts readily in these conditions.
Tatsoi preparing to bolt – note the smaller leaves and developing flower buds
Photo Pam Dawling
  • ·         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, or because the rows did not get sufficiently thinned.
  • ·         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 wins. High salt levels are another stressor, particularly in hoophouses.
Bolting Russian kale in our hoophouse March 28
Photo Pam Dawling

Avoiding or postponing bolting

  •  ·         Investigate, record and follow local last planting dates for early spring crops, and first planting dates for fall crops.
  • ·         For some crops there are varieties that are resistant to bolting, such as ‘Boltardy’ beets. If you have had repeated trouble with a particular crop bolting, look for bolt-resistant varieties. Florence fennel is particularly prone to bolting so try ‘Amigo’, ‘Victorio’ and ‘Pronto’ varieties and sow in summer for fall harvests. White and brown onions are less prone to bolting than red varieties.
  • ·         Onions grown from sets (plants stymied in mid-growth) are prone to bolting. Grow onions from seed or plant heat-treated sets in early spring (exposure to high temperatures suppresses flower-bud formation)
  • ·         Try to avoid stressing your plants.
  • ·         Direct sow. Plants prone to bolting due to root stress (beets, carrots, radishes, turnips, and many herbs) grow best when you direct sow them, rather than transplanting. This allows their root systems to develop without interruption.
  • ·         Transfer seedlings to a larger pot before the roots get crowded (“root bound”)
  • ·         Harden off plants before transplanting. Get them used to outdoor conditions, avoiding shock.
  • ·         Cover plants in the event of a cold spell, which can keep them from being directly exposed to cold temperatures, rain, or snow.
  • ·         Use seaweed or kelp liquid fertilizer, which help plants handle stress better.
Bolting mustard greens on May 3.
Photo Pam Dawling
  • ·         To postpone bolting in spring, avoid chilling young brassica plants (above 5-8 true leaves, or with a stem diameter above a certain size), below 40°F for a few days, or longer at 50°F (10°C). The interaction of plant size (age) and cold temperatures makes the plant flower. Older plants are more likely to bolt than young plants at the same cold temperature. Young hardened-off plants are very resistant to bolting. If broccoli and cauliflower plants are stressed into flowering while young, the small plants will only produce small heads.
  • ·         Coax your vegetables to maturity quickly and efficiently so they’re ready to eat before the plants have a chance to flower.
  • ·         Mulch spring crops early to help keep the soil and roots cooler, extending the harvest. We have found this to be especially helpful with spring cabbage and broccoli.
  • ·         Cover near-mature bulbing onions during cold spells to protect them from bolting.
  • ·         Use shadecloth to keep greens and lettuce cool as the season warms, or plant them in the shade of other plants
  • ·         Consider the timing of sowing. Grow storage carrots and beets in the fall, not the spring.
  • ·         Many cool-season crops mature better before temperatures get to 80°F (27°C), so plan accordingly. If your springs usually heat up fast as ours do, start earlier, or plant in late summer, fall, or even winter, depending on your climate, and grow these crops in reliably cool weather.
  • ·         Plant later annuals after the summer solstice to grow in the decreasing daylength without risk of bolting (unless another factor such as stress or temperature comes into play).
  • ·         Once cold-hardy plants are big, they can endure cold winter temperatures. They will not bolt until the day length is lengthening again (after the Winter Solstice) and the temperature starts to rise.
  • ·         Brassica greens started in hot conditions do not usually bolt if they have enough water. I recommend both Tokyo bekana and Maruba Santoh (both “celery cabbage” types of Asian greens), for summer substitutes for lettuce. You do have to grow them fast, with plenty of water, and insect netting if you have brassica leaf pests.
  • ·         In central Virginia for outdoors in spring, the only Asian green we grow is senposai, which we have found to withstand bolting until a bit later than others. There may be other loose-leaf Asian greens we could grow, but spring can go from too cold to too hot very quickly here.
Bolting senposai on May 3
Photo Pam Dawling
  • ·         To prevent bolting in Asian greens, sow these crops from July onwards. Asian greens bolt as nights become warmer  on average above 50-55°F (10-13°C)
  • ·         Winter radishes will only form a good root if they are planted in late summer or fall as the days get shorter.
  • ·         Sow quick-maturing plants like lettuce, cilantro, or radish regularly. Succession sowing can keep some plants always coming into maturity instead of relying on one sowing to last a long time without bolting in the garden. 
  • ·         If you grow biennial plants and harvest them in the first year, they are unlikely to bolt. A few specimens may still do so. Chard is cold-sensitive, and by delaying sowing until April, we can  grow chard all summer as a fresh cooking green, and it will not bolt no matter how hot it gets. We cannot keep kale and collards producing all summer as gardeners in cooler climates do.
  • ·         For early harvests of biennials, start the plants in plug flats or soil blocks indoors, planting them out when the weather is more settled and avoiding cold stress.
  • ·         Dry soil can also encourage bolting, particularly with cabbages, cauliflower, arugula and spinach. To avoid this, provide ample water.
  • ·         If the compost is not nutritious enough, top-dress with more compost.
  • ·         For over-wintered leeks and onions, bolting can be delayed by topdressing with 2-3oz per sq yd (70-100g per sq m) of nitrogen rich fertilizer very early in the new year
  • ·         Pick off the outer leaves from leafy crops such as lettuce, keeping the plants from maturing. As well as providing you with multiple harvests, this can extend the harvest period by as much as 10 weeks, although in hot weather the flavor may still become bitter, even without bolting. Grow Batavian varieties in hot weather.
  • ·         With some crops, like basil, if you catch a plant in the very early stages of bolting, you can temporarily reverse the process by snipping off the flowers and flower buds. The plant will go back to producing leaves and will stop bolting. In most plants (such as broccoli and lettuce) this only buys you a little extra time to harvest the crop.
  • ·         Cabbage wrangling: If a cabbage is mature and preparing to split open (a stage of bolting) before you are ready to harvest, you can get a firm hold on the head and give it a quarter turn. This will break some of the feeder roots and reduce the water uptake, delaying splitting.
Bolting over-wintered mizuna, Scarlet Frills and Golden Frills in March in our hoophouse.
Photo Pam Dawling

 Some specific examples

Lettuce is one of the vegetables most frequently seen bolting. I’ve even seen photos of bolting lettuce in garden magazines, with no acknowledgement that the plants are only fit for the compost heap.

The bitter taste of bolting lettuce is caused by a rapid buildup of compounds called ‘sesquiterpene lactones’. Plants manufacture these compounds to provide resistance to leaf-eating insect pests. The plants also speed up their production of seeds to grow the next generation.

Onions (excerpted from Sustainable Market Farming)

Onions are a biennial plant. When onion plants experience an extended period of cooling temperatures, such as winter, they go dormant. When temperatures rise, they start growing again. After being exposed to cold temperatures, smaller seedlings with a diameter less than pencil thickness (3/8” or 1 cm), and fewer than six leaves will resume growth and not usually bolt. Over-large transplants are more likely to bolt. If seedlings are becoming thicker than a pencil before you can set them out, undercut 2″ (5 cm) below the surface to reduce the growth rate.

The trigger for the transition from bulbing to flowering is temperatures below 50°F (10°C) for 3-4 weeks, after the plants have six leaves or more. This can happen, if you are unlucky, after an unexpected cold period in spring. Avoid bolting because the bulbs start to disappear to feed the growing flower stems. Bolted onions will not dry down to have tight necks and so will not store.

It is possible in our climate (and perhaps yours) to sow onions in the fall and plant the seedlings out in the early spring, for bigger vegetative growth and therefore the chance of bigger bulbs. The temperature-and-size trigger limits how early in the fall seeds can be sown – if the seedlings have made lower stems larger than a pencil in diameter when winter closes in, the plants are likely to bloom in the spring rather than forming bulbs. A few onion plants will likely always bolt, especially if the spring is long with alternating warm and cool spells.

Starting seedlings in a hoophouse in early November works well for us. Previously we sowed outdoors in late September and protected the plants with row cover and cold frames, a system that would work fine somewhere warmer than zone 7. The hoophouse works well for us because the plants get much better air flow, are protected from very cold temperatures, and can be easily seen and cared for. The plants grow faster in the hoophouse than outdoors, so we must start them later. Outdoor sowings tend to suffer some winter killing and varying degrees of mold. The colder the temperatures the plants experience, the more likely it is for the larger ones to bolt before growing large bulbs. Hence a more moderate microclimate, such as a hoophouse, reduces the rate of bolting. In colder zones, a slightly heated greenhouse might work better for over-wintering.

A bed of spinach on May 9 – note how the leaves are pointy – the spinach is preparing to bolt.
Photo Pam Dawling

Spinach grows best in temperatures from 35-75°F (1-23°C). Spinach will begin to flower once spring days are longer than 14 hours and temperatures get above 75°F (23°C). The leaves become pointed (arrowhead shape), less fleshy, and the plants get taller, and develop a flower head in warmer weather. Plant spinach 4-6 weeks before the average date of the last frost in your region. You can also sow 6-8 weeks before the first fall frost. You can also plant seed in a cold frame in fall or cover late season plants with rowcover, for harvests during the winter or the following early spring. In warm weather grow chard or leaf beet instead of spinach.

Change your attitude

You can’t control the climate, the weather or the daylength. If you’ve taken the steps listed above and your plants are still bolting, change your attitude!

As soon as you see signs of your greens bolting, harvest the entire plant. According to some excellent cooks, flowering bok choy stems are tender and sweet and make a great addition to stir-fry and salads.

Learn to appreciate peppery arugula or slightly bitter lettuce (mixed in with other salad greens).  It can be more enjoyable than the bland tasting lettuce available in stores.

Bolted vegetables are food for pollinating insects such as bees. Enjoy the beauty of sprays of yellow brassica flowers, majestic globes of leeks and onions, and lacy carrot umbels.

 

Root Crops in March

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.

See Planning to Grow Potatoes Again, the last part of a monthly series on growing potatoes, a dietary staple.

PART ONE: Planting potatoes (April)

PART TWO: Growing potatoes (May)

PART THREE: Potato pests and diseases (June)

PART FOUR: Harvesting potatoes (July)

PART FIVE: Storing potatoes (August)

PART SIX: Planning to grow potatoes again (September)

Beets

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

  • Green chit (pre-sprout) seed potatoes, see Planting potatoes .
  • 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.

Growing Vegetables in Space — Eat Like an Astronaut

Tokyo bekana in our hoophouse in late December.
Photo Pam Dawling

When I check to see which blog posts are gathering interest, the ones featuring Tokyo bekana are doing well this past year. You might wonder why. It’s because it’s one of the greens being grown on the International Space Station, and most people haven’t heard of it before. I’ve written about Tokyo bekana as a winter hoophouse green here on earth, and as a summer alternative to lettuce in places with hot summers (Virginia, Jamaica, Cuba).

According to an article in The Atlantic, the first plant to grow in space was thale cress, Arabidopsis thaliana, a spindly plant with white flowers, related to mustards, mature 6 weeks after sowing. This was in 1982, on board Salyut, a Russian space station of the era. Thale cress was chosen for practical reasons: a fairly quick life cycle that allows for many analyses in a short time.

Young Outredgeous lettuce in late November. The persistent galinsoga shows that our hoophouse has not yet reached freezing temperatures.
Photo Pam Dawling

The first vegetable grown and eaten on the International Space Station space was Outredgeous red romaine lettuce, in 2015. Bred by Frank Morton of Wild Garden Seed. 64 days to maturity on earth, 33 days in space, with intensely dark red, slightly ruffled leaves forming loose upright heads. “We are an organic seed farm in the Pacific Northwest, established in 1994, owned and operated by Frank and Karen Morton. We are known for farm-original varieties of many salad greens, vegetables, herbs, and flowers.” This is an Open Source Seed Initiative variety. The OSSI pledge: “You have the freedom to use these OSSI-Pledged seeds in any way you choose. In return, you pledge not to restrict others’ use of these seeds or their derivatives by patents or other means, and to include this pledge with any transfer of these seeds or their derivatives.” Read more about OSSI here!

Read Astronauts are about to eat the first food grown in space 2015.  The lettuce was grown for 15 months [? I think several rounds of planting], and the astronauts cleaned the lettuce with citric-acid-based sanitizing wipes before eating it.

Outredgeous lettuce growing in the Veggie module. NASA photo

Space Hydroponics – Veggie 2015

Space gardening has to be hydroponic – there is no soil involved. I am a big proponent of “Keep the Soil in Organic”, as I believe there are nutrients we don’t yet know about, that the plants take up from the soil in the proportions they need. But in space, you can’t do that, soil is way too heavy. If you watched The Martian movie, you saw some hilarious efforts to grow potatoes in “soil”.

In the Space Station is a plant growth system Veg-0, fondly called “Veggie,” a chamber about the size of a carry-on piece of luggage, typically holding six plants. The magenta light bathing the plants in Veggie is the result of a combination of red and blue LED lights. the most efficient way to get good plant growth. Green LEDS were added later so the plants look like edible food rather than strange decorations. Without gravity, plants use other environmental factors, such as light, to orient their growth.

To grow the first food crop, a root mat and six plant “pillows,” each containing ‘Outredgeous’ red romaine lettuce seeds, were put into Veggie. Inside each plant pillow is a growth medium including controlled-release fertilizer and calcined clay as used on baseball fields. This clay increases aeration and helps the plants grow. The plants get about 100 milliliters of water each to start the seeds growing. The pillows distribute water, nutrients and air around the plant root, to prevent the roots from drowning in water or being trapped in air (because of the way fluids in space tend to form bubbles).

Veggie remains on the station permanently as a research platform for other leafy plant experiments (and a source of food and psychological comfort!). The crew does get some fresh fruits and vegetables when a supply ship arrives at the space station, but the quantity is limited and they are soon gone.

See the 2015 article Meals Ready to Eat: Expedition 44 Crew Members Sample Leafy Greens Grown on Space Station

Watch this video to learn more about growing plants in space: https://www.youtube.com/watch?v=YFdwv9yrxD0&feature=youtu.be

For technical information about Veggie, visit here, and also see the 2020 Veggie Fact Sheet

2017-2018 More Space Crops

Next up in 2017 was our friend Tokyo bekana (a frilly Japanese mustard greens).

NASA photo

See the Modern Farmer article from February 2017: The Astronauts on the International Space Station Are About to Harvest Chinese Cabbage (Tokyo bekana)

Tokyo bekana was chosen for its fairly short stature and fast growth. Other contenders included Swiss chard, spinach and beets. The scientists who noted Tokyo bekana’s short stature haven’t seen the healthy 24” (60 cm) ones I just pulled up in our hoophouse today! In our hoophouse climate, it bolts in January, so our plan includes clearing the crop then and sowing spinach for bare-root transplants.

“We conducted a survey of several leafy green vegetables and looked at how the crops grew, how nutritious they were, and how a taste panel felt about them,” Gioia Massa, a scientist on the project, told Modern Farmer in an email. “The ‘Tokyo bekana’ Chinese cabbage variety was rated as the top in growth and the favorite of tasters.”

Waldmanns Dark Green lettuce https://www.johnnyseeds.com

Next the cut-and-come-again harvest method was tried with a few leafy salad greens using: Mizuna mustard, Outredgeous red romaine lettuce and Waldmann’s Green lettuce.

Green mizuna in our hoophouse in November.
Photo Pam Dawling

In some reports the little known Tokyo bekana is called, rather generally, but confusingly, Chinese cabbage or, more specifically, but mistakenly, bok choy, but we growers know the difference! Different sources in English use different names for Asian vegetables. I have a series of blogposts Asian Greens for the Month, which you can find by clicking that Category or using the search box.

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Asian greens divide into 3 groups:

  1. The turnip family, Brassica rapa, of Asian origin

Some crops are Brassica rapa pekinensis (napa cabbage, michihli, celery cabbage);

Others are Brassica rapa var. chinensis (bok choy): Tokyo bekana is either Brassica rapa var. pekinensis or var. chinensis

Brassica rapa var. japonica (mizuna),

Brassica rapa var. narinosa (tatsoi),

Brassica rapa var. perviridis (komatsuna)

2. The cabbage family, Brassica oleracea, of European origin (Kai-lan, Chinese kale)

3. The Chinese Mustard family, Brassica juncea (Ruby Streaks, Golden Frills, Red Rain)

Returning to 1a Brassica rapa var. pekinensis, there are two types: Wong Bok (Napa cabbage such as Blues, and cylindrical Michihli types) and Celery cabbage (pe tsai), which includes Tokyo bekana and the very similar Maruba Santoh.

  • A fast-growing, looseleaf, non-heading vegetable with light green leaves and white petioles.
  • Mild flavor, tender texture: can be substituted for lettuce
  • Can be ready for harvest in 3–4 weeks after sowing.
  • More heat tolerant than Napa cabbage. Cold tolerant to 25°F (-4°C)
  • Fairly bolt resistant

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Astronaut Serena Auñón-Chancellor harvests red Russian kale and dragoon lettuce from Veggie on Nov. 28, 2018, just in time for Thanksgiving. The crew got to enjoy a mid-afternoon snack with balsamic vinegar, and Auñón-Chancellor reported the lettuce was “delicious!”
Credits: ESA/Alexander Gerst

Advanced Plant Habitat 2018

There are two Veggie units aboard the station, along with a more sophisticated growth chamber, the Advanced Plant Habitat.

The Advanced Plant Habitat (APH) is a growth chamber on the Space Station for plant research like Veggie. It uses LED lights and a porous clay substrate, and a controlled-release “fertilizer” delivering water, nutrients and oxygen to the plant roots.

Unlike Veggie, APH is sealed, and automated with cameras and more than 180 sensors that are in constant interactive contact with a team on the ground at Kennedy, so it doesn’t need day-to-day care from the crew. It has more colors of LED lights than Veggie, and also white, far red and even infrared to allow for nighttime imaging.

APH had its first test run on the space station in Spring 2018 using Arabidopsis thaliana (good old thale cress) and dwarf wheat.

Astronauts have grown eight different types of leafy greens in Veggie at different times. NASA is building up the ingredients for a pick-and-eat salad; or rather, a pick, sanitize and eat salad since there is no way to cook on the station yet.

Dragoon lettuce, Johnny’s Seeds

In 2018, the Space Station grew Dragoon lettuce, a green mini romaine. Compact and uniform. Leaves are thick and have an excellent, crisp texture. Heads are very dense, hold well in the field. Bolting and tipburn tolerant. Resistant to downy mildew, lettuce dieback lettuce mosaic virus and an aphid. For spring, summer, and fall on earth, anytime in space. Suitable for hydroponic systems. By contrast with Outredgeous, Dragoon is Utility Patent granted, meaning other people are prohibited from making, using, or selling the “invention” without authorization.

Another 2018 crop was Red Russian kale

Red Russian kale March 7
Photo Pam Dawling

Recent Space Veggies 2019-2020

In 2019 the Space Station crew cultivated Wasabi mustard (eaten as a microgreen after 10 days of growth, or after 40-45 days as leafy greens) and Extra Dwarf pak choi (Harvest around 2-3″ tall, 30 days after sowing)

Wasabi mustard. Photo Specialty Produce

 

Extra Dwarf pac choi, Kitazawa Seeds


Astronauts Enjoy Space Veggies and Look to the Future of Cosmic Salads Nov 2019

In experiment Veg-04B (see list below) with Veggie, a plant growth unit on the space station, the researchers tested how the quality of light and fertilizer affects the microbial safety, nutritional value and taste of mizuna. Astronauts completed the second of three harvests of this mildly tangy, leafy salad vegetable.

Growing Plants in Space | NASA, January 2020

“A lack of vitamin C was all it took to give sailors scurvy, and vitamin deficiencies can cause a number of other health problems. Simply packing some multi-vitamins will not be enough to keep astronauts healthy as they explore deep space. They will need fresh produce.

Right now on the space station, astronauts receive regular shipments of a wide variety of freeze-dried and prepackaged meals to cover their dietary needs – resupply missions keep them freshly stocked. When crews venture further into space, traveling for months or years without resupply shipments, the vitamins in prepackaged form break down over time, which presents a problem for astronaut health.

NASA is looking at ways to provide astronauts with nutrients in a long-lasting, easily absorbed form—freshly grown fresh fruits and vegetables. The challenge is how to do that in a closed environment without sunlight or Earth’s gravity.”

Microbes in Space

March 2020 Researchers examined the microbial communities growing on the Space Lettuce. A diverse community of microbes lives on typical Earth-grown plants. These may include commensals (which neither harm nor benefit their host), or other microbes. Because microbes can affect the health of plants and those who eat the crops, researchers studied the communities of fungi and bacteria growing on the lettuce.

They identified the 15 most abundant types of microbes on the leaves and 20 in the roots, and found that the identity and range of these microbes was similar to Earth-grown lettuce. This was surprising, given the unique conditions in the Space Station. The scientists had expected to find different microbial communities present.

Happily, none of the bacteria they detected are known to cause disease in humans. Tests confirmed the absence of dangerous bacteria known to occasionally contaminate crops, such as E. coli, Salmonella, and Staphylococcus aureus. The numbers of fungal spores on them was also in the normal range for produce graded as fit for human consumption.

The Next Frontier -Roots in Space

On Nov. 27, 2020, NASA astronaut and Expedition 64 Flight Engineer Kate Rubins checks out radish plants growing for the Plant Habitat-02 experiment that seeks to optimize plant growth in the unique environment of space and evaluate nutrition and taste of the plants.
Credits: NASA

See the latest (December 2020) Astronauts Harvest Radish Crop on International Space Station

Watch Radishes Growing in Space: 27 Days in 10 Seconds

NASA astronaut Kate Rubins harvested radish plants growing in the Advanced Plant Habitat (APH) aboard the International Space Station. She carefully wrapped each of the 20 radish plants in foil, putting them in cold storage for the return trip to Earth in 2021, for further study. Note they didn’t get to eat any.

This is the first time NASA has grown radishes on the orbiting laboratory in the APH. Radishes were chosen because they are well understood by scientists and reach maturity in only 27 days on Earth, under optimal conditions. Radishes are genetically similar to Arabidopsis, thale cress, that researchers have long studied in microgravity.

Radishes are a different kind of crop from the leafy greens that astronauts previously grew on the space station, or dwarf wheat which was the first crop grown in the APH. Root crops require certain triggers to initiate root swelling, and also flowering (not wanted if you want to eat the roots!) Growing a range of crops helps determine which plants can thrive in microgravity and be part of offering variety and nutritional balance for astronauts on long missions.

Unlike previous experiments in NASA’s APH and Veggie, which used clay pillows loaded with a slow-release fertilizer, this trial relies on precise quantities of minerals.

Sophisticated control cameras and more than 180 sensors in the grow chamber let researchers at the Kennedy Space Center monitor growth and regulate moisture levels, temperature, and carbon dioxide concentration.

For the future, NASA hopes to figure out how to grow tomatoes, peppers, beans, and berries in space. And microgreens.

For more generally space diet info, see: Space Food Photos: What Astronauts Eat in Orbit 2013

All Veggie Crop Experiments for Human Consumption 2015-2019

Overall, 15 different types of plants have grown in space in Veggie. Researchers at Kennedy Space Center have tested more than 100 crops on the ground. Click the link to read about them all.

Veggie Crops not for human consumption include more of the same crops, and also zinnias, lentils, mustards and radishes, brome grass, algae and tests of a new type of grow chamber, the Passive Orbital Nutrient Delivery System (PONDS)

Cuban Agroecology Tour: Finca Agroecológica El Paraiso, Viñales

Finca Agroecológica El Paraiso, Viñales. View from the restaurant
Photo Pam Dawling

Cuban Agroecology Tour: Finca Agroecológica El Paraiso, Viñales

Here’s another post from my January 2020 group agroecology trip with Organic Growers’ School to Cuba. I’m posting about this sporadically as I organize my photos and journal.

Day 5 – Saturday January 11 lunch and afternoon

After visiting La Palma, a farm in Pinar del Rio province primarily growing tobacco, and Manolo Tobacco Farm to see cigars made, we went to a farm restaurant called La Finca Agroecologica el Paraiso. Wilfredo is the main farmer and his daughters are the main chefs.

Tidy raised beds and mountain view, Finca Agroecológica El Paraiso, Viñales, Cuba.  Photo Pam Dawling

The farm has 8.9 hectares, with 200 vegetable beds and 80% of the produce is sold through their restaurant, and 20% to hospitals etc (I think that is a legal requirement in Cuba). The restaurant is at the top of the hill, affording beautiful views of the farm.

Part of the vegetable gardens at Finca Agroecológica El Paraiso, Viñales, Cuba. Photo Pam Dawling

We had an exceptionally delicious lunch starting with an anti-stress herbal cocktail. Following that we had squash soup, sweet potatoes, taro, squash, lettuce, cabbage, cucumbers, pickled beans, pickled cucumbers, pork, beef, fish, rice and beans. The most vegetables I ate all week! (Food for tourists tend to be meat focused, although the places we visited could cater for vegetarians and vegans.) We enjoyed flan for dessert.

Outdoor classroom and banana tree at Finca Agroecológica El Paraiso, Viñales, Cuba
Photo Pam Dawling

After lunch we were given a guided tour of Finca Agroecológica El Paraiso. The boxed beds were very tidy, and they are all hand watered with water pumped from the river.

Creole spinach – does anyone recognize this plant? Finca Agroecológica El Paraiso, Viñales, Cuba.  Photo Pam Dawling

Creole spinach – see photo above. I do not know the Latin name for this vegetable, and in my research of hot weather cooking greens, particularly alternatives to spinach, I had not come across this crop before. Leave a comment if you know what it is.

Star garden at Finca Agroecológica El Paraiso, Viñales, Cuba
Photo Pam Dawling

Their “summer lettuce” is Tokyo bekana or maruba santoh. This use of the fast-growing chartreuse tender-leaved Asian green for a salad leaf was one I saw several times in Cuba. I thought I’d invented it! Haha! One summer when our lettuce did not grow according to plan, we served some Tokyo bekana as lettuce, and many people did not notice a difference! (Enough salad dressing will mask any vegetable flavor!) Some farms and restaurants simply call it “lettuce” or “summer lettuce”, some say it is a kind of pak choy, and a few can provide the actual name.

Finca Agroecológica El Paraiso , Viñales, Cuba. Tokyo bekana used as “summer lettuce”. Photo Pam Dawling
Herbs and flowers growing at Finca Agroecológica El Paraiso, Viñales, Cuba.
Photo Pam Dawling

The farm grows aromatic herbs to deter bugs. They use tobacco stem solution to kill pests. Nicotine is a strong generalist poison, which used to be part of the toolkit of organic growers here in the US and in the UK. It has the advantage of being short-lived, so produce can be eaten the day after spraying.

Finca Agroecológica El Paraiso, Viñales, Cuba. Lettuce bed. Photo Pam Dawling

See this video from Franny’s Farmacy. Made by two of my fellow travelers on the OGS Tour.

Finca Agroecológica El Paraiso, Viñales, Cuba – Learning about Sustainability and Organic Farming https://www.youtube.com/watch?v=egnKXHyu8_k

To see more, visit https://vimeo.com/146862523

 

 

Fast Growing Vegetables

Lettuce bed in May.
Photo Wren Vile

Maybe part of your response to Covid-19 is to grow more of your own food, and you are wondering what can bring fastest results. Or maybe you just want to leap into spring and have early harvests. Either way, here is information on some vegetable crops that offer fast returns; ways to get crops to grow faster; ways to get more crops from a small space and some sources for more information.

Vegetable Crops That Offer Fast Returns

In my blog post If Spring is Too Wet in March 2019, I included a paragraph on fast crops.

  • Ready in 30–35 days from sowing are baby kale, mustard greens, collards, radishes, spinach, chard, salad greens (lettuce, endives, chicories) arugula, and winter purslane. Beet greens from thinnings can be cooked and eaten like spinach.
  • Many Asian greens are ready in 40 days or less: Chinese Napa cabbage, Komatsuna, Maruba Santoh, mizuna, pak choy, Senposai, tatsoi, Tokyo Bekana and Yukina Savoy). See my Asian Greens of the Month category of posts. There’s a huge range of attractive varieties, they’re better able to germinate in hot weather than lettuce, and faster growing than lettuce. Most reach baby salad size in 21 days, full size in 40 days. Transplant 4-5 weeks after spring sowing, or direct sow. Nutritious as well as tasty. Flavors vary from mild to peppery; colors cover the spectrum: chartreuse, bright green, dark green and purple. A diversity of crops without a diversity of growing methods! Grow when you normally grow kale. Be aware that Asian greens sown in spring will bolt as soon as the weather heats up, so be ready to harvest a lot at once (if you planted a lot, that is!) You can make Kim Chee.
  • Tatsoi and our August sown catch crop of Tokyo bekana.
    Photo Pam Dawling
  • One summer we sowed Tokyo Bekana as a lettuce substitute. 20 days to baby size, 45 days to a (large) full size. We have also grown this at other times of year, when faced with an empty space we hadn’t planned for.
  • Mizuna and other frilly mustards are very easy to grow, and tolerate cold wet soil to 25°F (-4°C). In addition, they are fairly heat tolerant (well, warm tolerant). Use for baby salads after only 21 days or thin to 8″–12″ (20–30 cm) apart, to grow to maturity in 40 days. Mild flavored ferny leaves add loft in salad mixes and regrow vigorously after cutting.
  • Also ready in 30–35 days are spinach, chard, salad greens (lettuce, endives, chicories) and winter purslane.
  • Ready in 35–45 days are baby carrots (thinnings or the whole row), turnip greens (more thinnings!) endive, corn salad, land cress, sorrel, parsley and chervil. Some of the faster smaller turnip roots can also be ready in 45 days or less.
  • Ready in 60 days are beets, dwarf snap peas, broccoli, collards, kohlrabi, turnips and small fast cabbages (Farao or Early Jersey Wakefield).
  • Also ready in 50-60 days once we are past frosts: zucchini, yellow squash, bush beans, small cucumbers can grow fast.
  • Garlic scallions can be grown over-winter, but will grow quickly in spring. Plant scrappy little garlic cloves you don’t want to cook with in close furrows and wait till the leaves are 7” (18 cm) tall before digging up the plant and preparing like onion scallions (spring onions). Can be eaten raw, but more often cooked. You can also plant whole bulbs without separating the cloves. This is a good use for extra bulbs that are already sprouting in storage.
Our garlic scallions in February. we usually space the rows much closer than this. We’ll start harvesting when they reach 7″ in height.
Photo Pam Dawling
  • See other blog posts in my Cooking Greens for the Month series, and Asian Greens for the Month, as well as Lettuce of the Month
  • Try Eat-All Greens, an idea form Carol Deppe. Patches of carefully chosen cooking greens are sown in a small patch. When it reaches 12″ tall, Carol cuts the top 9″ (23 cm) off for cooking, leaving the tough-stemmed lower part, perhaps for a second cut, or to return to the soil.
Twin Oaks Eat-All Greens on October 19.
Photo Bridget Aleshire
  • Spinach is good for salad or cooking uses. Be aware that the fastest biggest spinach may not last long once it warms up! We have found Acadia and Reflect have good bolt-resistance from outdoor spring sowings.

Fast Varieties of Lettuce and Greens

Bronxe Arrow lettuce.
Photo by Southern Exposure Seed Exchange
  • Grow the right lettuce variety for the conditions. Ones that do well in early spring are often useless here after the end of March, or even mid-February. I like to sow 4 varieties each time (for the attractive harvests, and to reduce the risks if one variety bolts or suffers disease): at least one red and one romaine. We have 5 lettuce seasons, with different varieties:
    • Early Spring (Jan – Mar), 6 sowings
    • Spring (April – May 15), 5 sowings
    • Summer (May 15 – Aug 15), 17 sowings (lots of seed!)
    • Fall (Aug 15 – Sept 7), 9 sowings
    • Winter Sept 8 – 27, 9 sowings
  • Baby lettuce mix can be ready in as little as 21 days from mid-spring to mid-fall. A direct-sown cut-and-come-again crop, the plants regrow and can be harvested more than once in cool seasons. Weed and thin to 1″ (2.5 cm). When 3″–4″ (7.5–10 cm) tall, cut 1” (2.5 cm) above the soil. Gather a small handful in one hand and cut with using large scissors. Immediately after harvesting, weed the just-cut area so the next cut won’t include weeds
  • Leaf lettuce can be harvested by the leaf much sooner than waiting for a whole head of lettuce.
  • Small-leaf lettuces (aka Eazyleaf, One-Cut, Multi-Cut, Multileaf): Johnny’s Salanovas, Osborne’s and High Mowing’s Eazyleaf; Tango, Oscarde, and Panisse (older varieties) too. Full-size plants can be harvested as a head, or harvested with a single cut, providing a collection of bite-sized leaves. Or just one side (or the outer leaves) of the plant can be cut and the plant will regrow for future harvests. Growing multileaf heads takes 55 days, compared to 30 days for baby lettuce.
Buckley red oakleaf single-cut multi-leaf lettuce.
Photo High Mowing Seeds
  • Other greens can be sown in close rows for harvesting as salad crops at a height of 3”-4” (7-10 cm). These are called mustard mixes or brassica salad mixes.
  • Many cooking greens can be used as salad crops while plants are small, as you thin the rows of direct-sown crops.

Ways to Get Crops to Grow Faster

  • Sow when the conditions are right. Soil temperature is important. I have a table of soil temperatures in Year-Round Hoophouse on page 208. Vegetable Seed Germination: Optimum soil temperatures for germination and days to emergence, where known.
  • Grow transplants. By starting your plants in a place with close-to-ideal temperatures, rather than direct-seeding when it’s still a bit too chilly outside, you’ll get bigger plants sooner. You’ll also buy time to prepare the soil where you are going to plant out.
  • Find warm sheltered micro-climates, in front of a south-facing wall for example.
  • Make your own warm sheltered micro-climates with rowcover or low tunnels.
  • Take advantage of plastic mulch to warm the soil, for crops that like warmth. Regular black plastic mulch will need to be removed at the end of the growing season, but biodegradable mulch does not. However, if you are taking over part of your yard near your house, I should tell you that you will see shreds of the bioplastic next year. See Setting out biodegradable plastic mulch by hand
Rolling biodegradable plastic mulch by hand
Photo Wren Vile
  • Consider landscape fabric with planting holes burned in, as a reusable alternative to throw-away or biodegradable mulch.
  • Use mixes for salads: Our general salad mix harvesting approach is to mix colors, textures and crop families. I like to balance lettuce of different kinds with chenopods (spinach, baby chard, Bull’s Blood beet leaves) and brassicas (brassica salad mix, baby tatsoi, thinnings of direct-sown brassicas, chopped young leaves of Tokyo bekana, Maruba Santoh or other Asian greens, mizuna, other ferny mustards such as Ruby Streaks, Golden Frills and Scarlet Frills). See Making salad mix
  • Microgreens: See Andrew Mefferd The Greenhouse and Hoophouse Grower’s Handbook.
  • When the weather warms up, consider using shadecloth for heat-sensitive plants, particularly lettuce, but any of the cool weather greens you still have by then.
  • In warm weather, greens and lettuces inside a tipi of pole beans will benefit from the shade.

Ways to Get More Crops from a Small Space

  • With transplants, you can fit more crops into each bed throughout the season, because each crop is occupying the bed for less time than if direct-sown.
  • Transplanting can help you grow more successions of summer crops, as each one needs less time in the garden or field.
  • Grow a vertical crop on a trellis and something short in the space below it. You can even use the same trellis twice, growing tomatoes after peas, for instance.
Spinach and peas in a relay planting scheme.
Photo Twin Oaks Community
  • Relay Planting is a method of growing short crops alongside taller ones. We have often sown peas down the center of a bed of overwintered spinach. As the peas grow tall, we trellis them, and continue harvesting the spinach. When the spinach bolts, we pull it up. This overlap of bed use lets us get more crops from a bed in less time than if we sowed the crops one after another. We have also sowed peanuts down the middle of a bed of lettuce on the same date we transplant the lettuce. We make sure to use vertical romaine lettuces rather than sprawly bibbs or leaf lettuces. We have transplanted okra down the middle of a bed of early cabbage. This does involve breaking off outer leaves of the cabbage if they are about to smother the okra.
  • Sow some slower-maturing crops the same time as you sow the fast ones, so you have food later as well as sooner! Carrots, turnips, cabbages, broccoli, collards, kohlrabi,
  • Sow some multiple-harvest crops to save work later. Greens that are harvested by the leaf, rather than the head, offer good value.

Sources for More Information

  • In High-Yield Vegetable Gardening, Colin McCrate and Brad Halm point out that when planning what to grow, it’s important to consider how long the crop will be in the ground, especially if you have limited space.
  • Cindy Conner in Grow a Sustainable Diet: Planning and Growing to Feed Ourselves and the Earth, leads you through the process of identifying suitable crops for food self-reliance, and provides a worksheet to help you determine Bed Crop Months. For each bed, determine how many months that food crop occupies that bed and so assess the productivity value of one crop compared with another. Short season crops grow to harvest size in 30-60 days, allowing series of crops to be grown in the space, and feeding people quickly. If all your nutrients are to come from your garden, you will need to pay attention to growing enough calories. Otherwise you’ll lack the energy to get to the end of the season!
  • Curtis Stone, in The Urban Farmer, distinguishes between Quick Crops (maturing in 60 days or less) and Steady Crops (slower maturing, perhaps harvested continuously over a period of time). He has designed a Crop Value Rating system based on 5 characteristics. To use this assessment, you look at each characteristic and decide if the particular crop gets a point for that characteristic or not. Then look for the crops with the highest number of points. Spinach gets all 5 points; cherry tomatoes only 3. The smaller your farm, the higher the crops need to score to get chosen. His 5 are:
  1. Shorter days to maturity (fast crops = chance to plant more; give a point for 60 days or less)
  2. High yield per linear foot (best value from the space; a point for1/2 pound/linear foot or more)
  3. Higher price per pound (other factors being equal, higher price = more income; a point for $4 or more per pound)
  4. Long harvest period (= more sales; point for a 4 month minimum)
  5. Popularity (high demand, low market saturation)
  • Steve Solomon in Gardening When it Counts provides tables of vegetable crops by the level of care they require. His Easy List: kale, collards, endives, chicories, spinach, cabbage, Irish potatoes, sweet potatoes, all cucurbits, beets, chard, sweet corn, all legumes, okra, tomatoes (followed by the more difficult eggplant, peppers).
  • See my blog post How to Decide Which Crops to Grow
  • See my article Intercropping: Minimize Your Effort While Maximizing Yields, in the Heirloom Gardener of Spring 2018.
  • Jennifer Poindexter on the Morning Chores Site has a nice simple web post on 16 Fast Growing Vegetables That Will Give You a Harvest Quickly
  • Steve Albert on the Harvest to Table website has a good post on Quick-Growing Vegetable Crops. It includes recommended fast-growing varieties of 29 crops.

Cooking Greens in December

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

Cooking Greens to Harvest in Central Virginia in December

In December there’s chard, collards, kale, komatsuna, senposai, , spinach, tatsoi, and Yukina savoy, Eat-All Greens from the outdoor garden and also stored cabbage. The most cold-hardy greens start to come into their own.

From the hoophouse we continue harvesting chard, kale, senposai, spinach, tat soi thinnings or leaves, Tokyo bekana/Maruba santoh leaves (if we have not yet harvested whole plants because we saw signs of bolting), turnip greens, Yukina Savoy.

From late December we keep a close eye on the Chinese cabbage and pak choy, for signs of bolting. Normally these will bolt in January, so we harvest the whole plants that month. But we have sometimes needed to harvest the plants before we get to January.

Cooking Greens to Sow in Central Virginia in December

Outdoors, we sow nothing

Brassica (mustard) salad mix in our hoophouse in late November.
Photo Pam Dawling

In the hoophouse, on December 18 we sow brassica salad #2. Sometimes called mustard mixes, these are mixed brassicas to cut like baby lettuce mix when they are still small. Often we make our own mix at this time of year, using leftover seeds that we don’t want to keep for next year. We are busy working on our seed inventory and seed orders, so it gives us a use for odds and ends of packets. Just avoid bristly-leaved radishes and turnips! Using random seeds works for us because we do not expect yield-miracles. We will not get a lot of cuts from these plants before they bolt in March or early April. Our first round of Brassica Salad Mix is sown October 2 and is harvested several times between October 29 and December 21. Much faster growth in October and November than in December and January! We make a third sowing on New Year’s Day.

Cooking Greens to Transplant in Central Virginia in December

Outdoors, we transplant nothing

In the hoophouse, we transplant spinach, senposai, Yukina Savoy, Frills (frilly mustards) to fill gaps that occur in the beds. We replace spinach with spinach, brassicas with brassicas wherever possible, filling gaps caused by either harvesting whole plants or Bad Things (those are usually fungal diseases).

Our Filler Greens are sown October 10 and October 20 (brassicas) and October 24 and November 9 (spinach). JANUARY 25 (I originally mistakenly said December 25) is our official last date for using the brassica fillers because there is not enough time for them to make worthwhile growth before they bolt. After that date we fill all gaps with spinach plants.

Short rows of filler greens, lettuce and spinach in the north edge bed of our hoophouse in December.
Photo Kathleen Slattery

Other Cooking Greens Tasks in Central Virginia in December

While watching the temperature forecasts, we continue to harvest the hardier greens, such as chard, yukina savoy, collards, kale, spinach and tatsoi. If low temperatures are forecast we might add rowcover to some of the beds, or decide to clear the vulnerable crops and put them in the cooler.

See Cooking Greens for November for more details on winter-kill temperatures

This winter we have already had 16°F (-9°C) and 18°F (-8°C) in mid-November. As temperatures drop, we clear these crops before their winter-kill temperatures happen:

15°F (–9.5°C): kohlrabi, komatsuna, some cabbage, red chard (green chard is hardy to 12°F (-11°C)), Russian kales, rutabagas if not covered, turnip leaves, most covered turnips.

12°F (-11°C): Some beets (Cylindra,), some broccoli, Brussels sprouts, some cabbage (January King, Savoy types), most collards, senposai, some turnips (Purple Top).

10°F (-12°C): Covered beets, Purple Sprouting broccoli for spring harvest (too cold in central Virginia for us to grow that), a few cabbages (Deadon), chard (green chard is hardier than multi-colored types), some collards (Morris Heading can survive at least one night at 10°F/-12°C), probably Komatsuna; Senposai leaves (the core of the plant may survive 8°F/-13°C), large leaves of savoyed spinach (more hardy than smooth-leafed varieties), Tatsoi, Yukina Savoy.

5°F (-15°C): some collards, some kale (Winterbor, Westland Winter), smaller leaves of savoyed spinach and broad leaf sorrel. Some tatsoi. Many of the Even’ Star Ice Bred greens varieties are hardy down to 6°F (-14°C).

0°F (-18°C): some collards (Blue Max, Winner), Even’ Star Ice-Bred Smooth Leaf kale, some spinach (Bloomsdale Long Standing, Bloomsdale Savoy, Olympia). Vates kale survives.

Vates kale outdoors. An oleracea type, Vates is very cold-hardy.
Photo by Nina Gentle
Russian kale (napus type) gives us good yields in our hoophouse in January.
Photo Pam Dawling

Special Cooking Greens Topic for December: Understanding kale types

Russian and other Russo-Siberian kales (napus varieties) do better in the hoophouse than Vates blue curled Scotch (and other European oleracea varieties). Napus kales will make more growth at lower temperatures than oleracea kales, although they are not as cold-tolerant. “Spring” kales (napus) will persist longer into warmer weather than Vates (oleracea) can, from a spring sowing. The vernalization requirement for napus kales with about eight leaves is 10–12 weeks at temperatures below 40°F (4°C). Brassica oleraceae kales will start flowering after 10–12 weeks below the relatively balmy spring temperature of 50°F (10°C).

Special Cooking Greens Topic for December: Ordering Seeds (Adapted from Sustainable Market Farming)

Every year we try to introduce a new crop or two, on a small scale, to see if we can add it to our “portfolio.” Some-times we can successfully grow a crop that is said not to thrive in our climate.(Brussels sprouts really don’t). We like to find the varieties of each crop that do best for our conditions. We read catalog descriptions carefully and try varieties that offer the flavor, productivity and disease resistance we need. Later we check how the new varieties do compared with our old varieties. We use heirloom varieties if they do well, hybrids if they are what works best for us. We don’t use treated seeds or GMOs, because of the wide damage we believe they do.

Calculating the seed order

When we figure out how much seed to order we add in some extra for some things – crops that can be difficult to germinate, or we really don’t want to cut too close. We add 20 percent extra for most crops, but only 5 percent for kale, 10 percent for onions and collards and 30 percent for melons. These numbers are based on our experience – yours might be different. We also know which seed we can buy in bulk and use over several years. This gives us an additional security against poor germination, or plagues of grasshoppers or caterpillars. For me, a big bag of broccoli seed for each of our main varieties gives some kind of warm glow of horticultural security!

This is the time of year we adjust the “seed rate” (seed/100′ or /30 m) column of our spreadsheet using information from our past year, and we feed in the next year’s crop plan for varieties and succession plantings – everything we have decided so far about next year. We make notes about any problems or questions we need to resolve later, and we’re sure to order enough seeds to cover these eventualities. We have found it worthwhile to proofread our inventory and order form carefully before making our final decisions, as mistakes not discovered until planting day can be a big problem.

Sowing Rainbow Chard. in the greenhouse
Photo Pam Dawling

Formatting and placing seed orders

On the Seed Order version of our spreadsheet, we include columns for the name of the supplier we buy each variety from (we just use the initial), the item number in the catalog, the packet size and the price. (Be careful though, if you carry this information over from year to year – prices change.) Once we have composed our total seed order, we sort the orders by the name of the supplier. Then we can calculate the total price for each supplier. This also gives us the opportunity to look at price breaks for large orders and move an item from one supplier to another, if that makes sense. At this point we usually make a cup of tea and reward ourselves with an “impulse buy” or two, if that doesn’t push us up into a higher shipping cost bracket or blow the budget. We place our orders online these days, nice and early, to increase the chances of getting exactly what we want.

 

Forget Miami peas; Forget industrial hemp; Optimize your Asian greens

Forget Miami peas

For years I have been mentioning “Miami Peas” in my presentations about cover crops. At the Carolina Farm Stewardship conference I was asked what they are, by Mark Schonbeck, who knows cover crops well. (This is one of the wonderful benefits of attending conferences – meeting peers and mentors, and learning new things.)
I said it is a frost tender cover crop pea of the field pea type (not a southern pea). I can’t remember where I first heard about this cover crop, and we haven’t been using it on our farm, so it was time for a reality check when I got home. I can’t find any reference to Miami peas apart from the ones I’ve made! I believe it’s a type of Canadian field pea, but maybe it no longer goes by the Miami name, or maybe it never did! It’s embarrassing to promote untruths.
Spring forage peas from Seven Springs Farm, Virginia

Pinetree Seeds says:

This short term green manure smothers weeds well and adds nitrogen and other nutrients to the soil. Peas are often mixed with vetch, oats, or rye as an effective cover crop. The sprouts are delicious and you can even harvest the peas themselves for soup. This annual prefers cool well drained soil and has no frost tolerance. Sow 3 to 4 lbs per 1000 sq. ft.

For clarity, here’s what I now believe:
  • “Forage pea” and “Field pea” are terms that include the  hardy Austrian winter peas, that we do use and are big fans of, as well as frost-tender spring peas, also known as Canadian field peas.
  • Canadian field peas are not frost tolerant and are sold by Pinetree Seeds. among others.
  • SARE lists Canadian field peas as Spring Peas. SARE is a very reliable source of information. They say

These annual “spring peas” can outgrow spring-planted winter peas. They often are seeded with triticale or another small grain. Spring peas have larger seeds, so there are fewer seeds per pound and seeding rates are higher, about 100 to 160 lb./A. However, spring pea seed is a bit less expensive than Austrian winter pea seed. TRAPPER is the most common Canadian field pea cultivar.

  • Other spring pea varieties are Dundale and Arvika
  • There’s also a tropical Pigeon Pea, Cajanus cajan, which can grow in the Southern US, but that looks pretty different, and I don’t think that’s what I meant.
Pigeon Pea flowers, Cajanus cajan
Photo Wikipedia

 

Forget industrial hemp

I have been alarmed at how many small-scale growers are trying industrial hemp. Partly I’m hoping it won’t cause a shortage in locally grown food! I also wonder how well an industrial field crop grows on a small scale, and how the growers would deal with the permits, the processing and the marketing.

Read this report from The Modern Farmer about how industrial hemp is unsuccessful for most growers and how the market is swamped with would-be suppliers:

Thousands Began Farming Hemp This Year. It Hasn’t Gone How They Hoped.

Optimize your Asian greens production

Here’s my updated slideshow on Asian greens, which I presented at the Carolina Farm Stewardship conference. 

Check their website for details about other workshop sessions too. I believe my handouts, and those of other speakers, will soon be available on their website.

Click the diagonal arrow symbol to view this full screen., and click the forward arrow to start viewing.

Senposai is our star of Asian greens. Here’s a bed of senposai outdoors in spring.
Photo Kathryn Simmons