I just got back from the Virginia Association for Biological Farming conference in Roanoke. There I gave a half-day presentation on Year-Round Hoophouse Vegetables, which you can watch here:
The conference was very well-attended, and not everyone at my workshop on Friday, or the Alliums Year-Round 90 minute workshop on Sunday morning got a handout. I promised to post them here, and now I’m making good. I’m also posting the handout for the third workshop I gave, Asian Greens in the Winter Hoophouse. This rounds out the set, and gives a chance to those who went to a different workshop at that time to get a look in.
Our hoophouse beds after the nights at 2F (-17C) and 8F (-13C). Looking amazing! Pam Dawling
We were luckier with the weather than many people over the weekend (12/23-12/26/2022). And so were our vegetable crops. On Friday 12/23 we prepared for a suddenly very cold night. It was very windy as we battled to stop the hoophouse windows from blowing open. We finally got some shims, a hammer and a stepladder, and wedged them closed. They stayed that way until Tuesday 12/27. We were fortunate in getting no precipitation (I hate ice!) and no power outage.
Pool noodles repurposed as draft excluders. Pam Dawling
We fortified the doors with our rock collecting buckets, and prevented most of the under-door drafts with our pool noodle draft excluders. They have a rope running through them, which is hooked onto small cup-hooks on the door frame. We repurposed noodles that had been used as props at a party or some other kind of event. They had been covered in tube socks and had glued-on googly eyes.
Rolls of rowcover at the ready in our hoophouse. Pam Dawling
It was a bit unnerving being in the hoophouse as it creaked and groaned in the wind. In the winter we keep rolls of rowcover ready for any night we think will be below 8F (-13C). We unrolled the rowcovers by lunchtime and laid tools on the ends nearest the doors. I was worried that if we lost power, and therefore the inflation, it would get very cold indeed in the hoophouse.
The DIY manometer in our hoophouse. (the background lines have faded). Pam Dawling
Since we last changed the plastic we haven’t managed to get the recommended 1/3” (8.5mm) pressure difference in the “bubble” between the plastic layers, compared to our normal air pressure. Mostly we don’t even get ¼” (6.5mm). The “bubble” provides thermal insulation as well as physical strength against snow or ice buildup, and strong winds.
It got down to 2F (-17C) outdoors Friday night, and Saturday didn’t warm up much. I don’t actually know what the night temperature was in the hoophouse as our recorded low temperatures don’t make sense: 14F (-10C) for four consecutive nights (Fri to Mon). I suspect we didn’t reset the thermometer correctly. Usually the hoophouse can hold 8 F (4.5 C) degrees warmer than outdoors, but not 12 F (7 C). It looks like it did, perhaps because we didn’t open it all day!
Soil thermometer in our hoophouse on 27 December 2022. Pam Dawling
The soil is still nice and warm in there: 59F (15C). That really helps. The rowcovers are usually removed in the daytime, either pulled aside if we expect to need them again the next night, or rolled up out of the way. Most of the time they stay rolled up at the east end of the hoophouse. We appreciate not needing to deal with rowcovers most of the time! On Saturday 24th, the temperature maximum for the day outdoors was 24F (-4.5C), and we kept the rowcovers in place over the crops. On Sunday the high outdoors was 28F (-2C) so we pulled the rowcovers aside until the night. On Monday 26th the night-time forecast was benign enough that we rolled the rowcovers up. And now we get a milder spell.
Hakurei turnips with frozen yellow leaves where they touched the plastic (rowcover protected the plants). Pam Dawling
How did the crops fare? It’s not always obvious at first if a crop has been killed by cold or not, But I can now say with confidence that nothing died. The edge beds are always the coldest. The south edge bed had Hakurei turnips, delicious and notoriously the least cold-hardy turnip variety. Most of the globe of the turnip sits on the surface of the soil. You can see in the photo that some of the leaves, the ones right by the wall plastic, have been killed and turned yellow. But the roots themselves (with rowcover over them) seem fine.
Bright Lights chard with cold-damaged stems in our hoophouse north edge bed after nights at 2F and 8F Pam Dawling
Over the other side, in the north bed, we have some Bright Lights chard, among other things. Multi-colored chards are less cold-hardy than red ones, which in turn are less cold-hardy than green ones. We know we take a risk in growing Bright Lights through the winter, but we so enjoy the sight of the short pieces of colored stems in our salad mixes that we take the risk. Some of the stems have curled over, probably on their way to dying, but the plants live on, to provide many more salads this winter! And some cooked greens too.
Some of the giant senposai leaves, where not fully protected by the relatively narrow rowcover, have developed tan dead spots, so those leaves can just continue as the plants’ solar panels until we get tired of looking at them and decide they are no longer needed.
Each winter I update my Winter-Kill Temperatures of Cold-Hardy Vegetables list, except this past spring I had nothing new to add. Outdoors, I noticed today that the tatsoi has definitely died, the Vates kale and the spinach have survived (uncovered) and the small garlic leaves don’t seem troubled. The leftover lettuce transplants have been damaged, if not killed.
If you have a hoophouse, you may now be planning or planting crops for fall, winter and spring. If you don’t have a hoophouse, this is a good time of year to consider getting one. See Twenty Benefits of Having a Hoophouse at the end of that post. There are grants available from NRCS, including reparation levels of funding from traditionally underserved groups of people. There are now companies that will construct your hoophouse for you, if you don’t want to do it yourself, or can’t. If you do want to build your own, there are detailed instructions in my book The Year-Round Hoophouse. You can buy the book here on my Books page direct from me, or from my publisher New Society, or you can buy it wherever books are sold.
The Year-Round Hoophouse cover
I have many posts about winter hoophouse vegetables, so rather than try to write something completely new on the topic, I am going to give you a guide to find your way around the information already here.
Hoophouse bed broadforked to loosen up slumped soil. I’m happy to say our soil structure has improved in the 18 years since this photo was taken! Photo Pam Dawling
Choosing Hoophouse Winter Crops
(see also my post categories on the right side of the computer screen, for special posts on Asian Greens, Cooking greens, lettuce and root crops)
See my recent post for info about fall broccoli and cabbage. Here I provide some more information and discuss other brassicas you could grow in the fall.
Temperature and Timing for Fall Brassicas
Germination: Brassica seeds will germinate at soil temperatures from 41°F (5°C) to 95°F (35°C). 41°F (5°C) can take 45 days for some brassicas, but in summer and fall, this isn’t the end of the thermometer we worry about! In summer and fall, soil temperatures are enough to germinate brassicas in 3-10 days. Optimum soil temperatures for germination are
77°F (25°C) for most Asian greens, broccoli, Brussels sprouts, cauliflower, collards, kohlrabi, pak choy;
86°F (30°C) for cabbage, including Napa cabbage, kale, turnips and rutabagas;
68°F (20°C) for mustard greens, and perhaps arugula (which might do better even cooler)
Vates kale seedlings for bare-root transplanting outdoors. Photo Pam Dawling
Cold-Hardiness: Consult this list of winter kill (air) temperatures for brassicas, for the crops you are growing.
32°F (0°C): some cauliflower curds, some pak choy
27°F (-3°C): many cabbage varieties
22°F (-6°C): some varieties of arugula
20°F (-7°C): broccoli heads (maybe OK to 15°F (-9.5°C)), some Brussels sprouts, some cabbages (the insides may still be good even if the outer leaves are damaged), some cauliflower varieties, some collards (Georgia Cabbage Collards, variegated collards), some mustards/Asian greens (Tendergreen), radishes (Cherry Belle), most turnips (Noir d’Hiver is the most cold-tolerant variety).
15°F (-9.5°C): some broccoli and cauliflower leaves, some cabbage (Kaitlin, Tribute), Red Russian and White Russian kales, kohlrabi, rutabagas (American Purple Top Yellow, Laurentian), most covered turnips, winter cress.
12°F (-11°C): some broccoli perhaps, some Brussels sprouts, some cabbage (January King, Savoy types), most collards, Koji greens, covered rutabagas
10°F (-12°C): Purple Sprouting broccoli for spring harvest, a few cabbages (Deadon), some collards (Morris Heading can survive at least one night), Belle Isle upland cress, probably Komatsuna, Chinese Thick-Stem Mustard may survive down to 6°F (-14°C), covered winter radish (Daikon, China Rose, Shunkyo Semi-Long survive), Senposai leaves (the core of the plant may survive 8°F/-13°C), Tatsoi, Yukina Savoy.
5°F (-15°C): some kale (Winterbor, Westland Winter), many of the Even’ Star Ice Bred greens varieties and the Ice-Bred White Egg turnip are hardy down to 6°F (-14°C)
0°F (-18°C): some collards (Blue Max, Winner, McCormack’s Green Glaze), Even’ Star Ice-Bred Smooth Leaf kale
-5°F (-19°C): Leaves of overwintering varieties of cauliflower, Vates kale survives although some leaves may be too damaged to use. Lacinato Rainbow Mix kale may survive this temperature.
Frosty daikon leaves. Photo Bridget Aleshire
Your Climate: Consult WeatherSpark. com to see when it begins to get too cold in your area. At our farm, the average daily low temperature on November 30 is 36°F (2°C). Decide your ideal harvest date for each crop. Although kohlrabi can take 15°F (-9.5°C), I’d want to get it all harvested by November 30.
Days to Maturity: Next factor in the number of days a crop takes to reach maturity. Work back from your desired harvest date, subtracting the number of days from sowing to maturity (or from sowing to transplant, plus from transplant to maturity). Work back another two weeks for the slowing rate of growth in fall. And perhaps work back another two weeks in case in gets colder earlier than usual. This provides your sowing date.
Mid-Winter Harvests: For crops that survive your winter, are you sowing to harvest in the fall, during the winter, or only in early spring? Brassicas for early spring harvest only can be sown in September or October in our climate. For those to be harvested during the winter, you need to have big enough plants going into the winter, to provide sustainable harvests (once a week in November and February and more in spring, plus maybe once a month in December and January)
Overwintered Vates kale. Photo credit Twin Oaks Community
Various Fall Brassica Crops
In the summer we try to have a No Visible Brassicas Month to break the lifecycle of the harlequin bugs. Once our spring kale is finished, the spring cabbage gathered in, and the spring broccoli mowed down, the only brassicas are seedlings hidden under insect netting. Our hope is to starve out the harlequin bugs or at least deter them from making too many more.
We sow other fall outdoor brassicas a bit later than cabbage and broccoli. These get transplanted from our netting-covered nursery seedbeds, to our raised bed area which is more accessible for winter harvesting and more suited to small quantities.
Asian Greens
Outdoors we grow Senposai, Napa Chinese cabbage and Yukina Savoy. We have also sometimes grown tatsoi and komatsuna. Note that senposai grows quite large – give it similar spacing to collards.
We sow Asian greens for outdoors in the last week of June and first week of July, aiming to eat them before we start harvesting the ones in the hoophouse, which feed us all winter. We use Asian greens outdoors as quick-growing greens to fill the gap before our main fall greens (spinach, kale, collards, cabbage, broccoli) are ready to harvest. We don’t grow a lot outdoors.
If you don’t have a hoophouse, you can sow for outdoors later into the fall than we do, to get a longer harvest season than you otherwise would. And you certainly can direct seed them.
Yukina Savoy outdoors in December, after several nights at 16-17°F (-8 to -9°C) Photo Kathryn Simmons
Collards
We sow collards in the first two weeks of July and transplant the bare-root transplants from the nursery bed when they are 3-4 weeks old. We plant at 18” (46 cm) in the row, with rows 12” (30 cm) apart. (if you grow a large kale, you might want similar spacing. Our Vates kale is small)
Morris Heading collards. Photo Kathryn Simmons
Brussels sprouts
are rather a challenge in our climate, and not worthwhile. We have worked on finding the best variety (Oliver) and timing for our situation. Harvest timing is critical, as Brussels sprouts will not overwinter here.
Cauliflowers
are a tricky crop for us too. Be sure to check the “days to harvest” for each variety (they vary widely) and sow at a realistic date to get a crop before too many frosts endanger the curds. The number of days quoted for fall varieties of cauliflower already allows for the expected rate of growth at that time of year, so the 14 days for slower growth isn’t a factor. However, cauliflower is more tender, so allow for the possibility of a fall frost earlier than average.
Harvested kohlrabi, Early White Vienna and Early Purple Vienna. Photo McCune Porter
Kohlrabi
We sow Vienna kohlrabi mid-July and transplant early August at 8” (20 cm) apart in the row, with 9-10” (23-25 cm) between rows. Later sowings (up till early September) would also work for the fast maturing varieties. Superschmelz Kohlrabi (60 days from transplanting) can also be summer sown for fall harvest. It produces 8-10” (20-25 cm) bulbs, which remain tender and an attractive globe shape.
Kale
We direct-sow two neighboring beds of kale on each of 8/4, 8/10, 8/16 and then carefully thin them, leaving one plant every 12” (30 cm). These plants grow quicker than transplants, as they have no transplant shock. Meanwhile, if we have gaps, we use the carefully dug thinnings from those beds to fill them. We want a lot of kale, and there isn’t time to transplant it all. Dividing up the sowings lets us focus on watering just one pair of beds at a time. Vates kale is the hardiest variety we have found, although I’d love to find a taller Scotch curled variety that could survive our winters (Winterbor does not survive as well as Vates).
An outdoor bed of young Vates kale Photo Kathryn Simmons
Rooty Brassicas
Radishes, rutabagas and turnips are also brassicas, but I won’t say more here. look in the further resources.
Brassica Aftercare
Brassicas started in hot conditions do not usually bolt if they have enough water.
Brassica seedlings under ProtekNet in August. Photo Pam Dawling
Protect seedlings and the new transplants with insect netting if you have brassica leaf pests (most of do!) You can remove the netting when the transplants are well established, or leave it on.
Use shadecloth to keep greens cool in hot weather, or plant them in the shade of other plants.
To keep crops in good condition later into the winter, use rowcover. I recommend thick Typar 1.25oz rowcover, which provides 6F degrees of cold protection. I wouldn’t spend the money on anything thinner, it’s too frustrating! We do not normally use rowcover in the winter for kale and collards, as they will survive without. In harsh winters we lose the collards.
Cultivation is a simple matter of hoeing, weeding, watering as needed, and watching for pests.
We grow some winter brassicas in our hoophouse: Russian kales, turnips, and Asian greens – more about those in my winter hoophouse posts (includes slideshow).
We are almost at a big turning point of the growing season, the Summer Solstice, the longest day. We know that day-length influences plant growth, and that after the Solstice, some crops will gradually take longer and longer to reach maturity (others will bolt). Crops more influenced by temperature (like sweet corn) will continue to mature faster while the summer temperatures rise.
Here in central Virginia, most brassicas are planted in spring and again in fall. Unless your broccoli keeps going all summer, consider sowing a new crop for fall. Although it can be hard to think about sowing seeds in mid-summer, it’s very worthwhile to grow fall brassicas because as they mature in the cooler fall days they develop delicious flavor, while weeds and pests slow down. These crops need little care once established. The most challenging part is getting the seedlings growing well while the weather is hot. However, unlike some cool weather vegetables such as spinach and lettuce, brassica seeds actually germinate very well at high temperatures. The ideal is 77-85°F (25-29°C), but up to 95°F (35°C) works. Given enough water, summer seedlings will emerge in only 3 days. Once they have emerged, the challenge begins. As well as temperature and moisture in the right ranges, the seedlings need light (very plentiful in mid-summer!), nutrients, good airflow, and protection from bugs. We deal organically with flea beetles, Harlequin bugs, and sometimes cabbage worms. Our main defenses are farmscaping, and netting (and previously, rowcover).
My book Sustainable Market Farming, has a chapter devoted to Broccoli, Cabbage, Kale and Collards in Fall.
Fall broccoli patch. Photo Kati Falger
Timing sowing of fall broccoli and cabbage
The number of days to harvest given in seed catalogs is usually that needed in spring – plants grow faster in warmer temperatures. To determine when to sow for fall plantings, start with your average first frost date (as an indicator of cooling temperatures), then subtract the number of days from seeding to transplant (21-28), the number of days from transplanting to harvest for that variety (given in the catalog description), the length of harvest period (we harvest broccoli for 35 days minimum), and another 14 days for the slowing rate of plant growth in fall compared to spring. For us, the average first frost is 10/14-10/20, and we sow 53-day broccoli 21+53+35+14 days before 10/14, which is 6/13-6/19. The last date for sowing broccoli and cabbage is about 3 months before the first fall frost date. In our case that means July 14–20.
Planning and crop rotations for fall brassicas
Our rotation plan shows us a long way ahead how many row feet of fall broccoli and cabbage we can fit in. By the time we order our seeds in the New Year, we know roughly what we expect to grow. In February we draw up a spreadsheet of how much of what to sow when.
Because fall brassicas are transplanted in summer, it’s possible to grow another vegetable crop, or some good cover crops, earlier in the year. An over-wintered cover crop mix of winter rye and crimson clover or hairy vetch could be turned under at flowering, and be followed by a short-term warm weather cover such as buckwheat, soy or cowpeas. Brassicas are heavy nitrogen consumers. To minimize pests and diseases, don’t use brassica cover crops.
Systems for growing fall broccoli and cabbage transplants
The same systems you use for growing transplants in spring can also work well for fall. It can help to have your plants outside on benches, above the 3’ (1m) height of flea beetles. A shade-house might be ideal too. Direct sowing, in “stations” (groups of several seeds sown at the final crop spacing), works for small areas.
We use an outdoor nursery seedbed and bare root transplants, which suits us best. The nursery bed is near our daily work area, so we’ll pass by and water it. Having the seedlings directly in the soil “drought-proofs” them to some extent. They can form deep roots, and do not dry out so fast.
For the seedbeds we use ProtekNet on wire hoops. Choose the mesh size carefully. One with small holes is needed to keep flea beetles away – 25 gm or 47 gm. Overly thick rowcover can make the seedlings more likely to die of fungal diseases in hot weather – good airflow is vital.
Sowing fall broccoli and cabbage
Brassica seedlings growing outdoors under insect netting. Photo Pam Dawling
Our rough formula for all transplanted fall brassicas is to sow around a foot (30 cm) of seed row for every 12-15’ (3.6-4.6 m) of transplanted crop row. We aim for 3 seeds per inch (about 1 cm apart). This means sowing 36 seeds for 10 plants transplanted on 18” (46 cm) spacing. And we do that twice (72 seeds for 10 plants!), in two sowings a week apart, to ensure we have enough plants of the right size.
Our seedbeds have an 8-week program – see the spreadsheet above for examples of our timing, quantities and varieties. I like to have a regular afternoon every week to grow the transplants. If you’re growing for fewer than 100 people, you won’t need a whole afternoon! Each week after the first week, we also weed the previously sown plants, and thin to 1” (2.5 cm) apart. Then we check the germination, record it, and resow if needed to make up the numbers.
Bare root brassica transplants under Proteknet. Photo by Bridget Aleshire
Transplanting fall broccoli and cabbage
We transplant most brassicas at 4 true leaves (3-4 weeks after sowing at this time of year). It is best to transplant crops at a younger age in hot weather than you would in spring, because larger plants can wilt from high transpiration losses. If we find ourselves transplanting older plants, we remove a couple of the older leaves to reduce these losses.
We transplant 6 days a week for an hour and a half or two hours in late afternoon or early evening, for 2-3 weeks. We water the soil in the plot an hour before starting to transplant. It is very important at this time of year to get adequate water to the plants undergoing the stress of being transplanted. Likewise, good transplanting technique is vital. Water a lot more than you do in spring. If you have drip irrigation, you can easily give a little water in the middle of each day too, which will help cool the roots.
One of our impact sprinkler tripods, in a broccoli patch. Photo Pam Dawling
We transplant broccoli and cabbage in 34” (86 cm) or 36” (91 cm) rows, which is wider than necessary. Beds or paired rows can fit more plants in the same space, while still allowing room to walk. We hammer in stakes along the row, and attach ropes between them. These both mark the rows for transplanting, and support the netting that we use after transplanting to keep the bugs off. An 84” (2.1 m) width netting can form a square tunnel over two crop rows, giving good airflow. Wire hoops are an alternative. Watering the soil before planting, as well as afterwards, helps survival during the hot summer days.
Aftercare of fall brassicas
About a month after transplanting the broccoli and cabbage (late August-early September), we remove the netting, stakes, ropes and the sticks we use to hold down the netting edges, then hoe and till between the rows. Next we broadcast a mix of mammoth red clover, Ladino white clover and crimson clover. We use overhead sprinkler irrigation to get the clover germinated, and it also helps cool the brassicas. The ideal is to keep the soil surface damp for the few days it takes the clover to germinate. Usually watering every two days is enough. We may replace the netting if pest pressure seems bad.
Fall broccoli undersown with a mixed clover winter cover crop. Photo Nina Gentle.
If all goes well, we keep the clover growing for the whole of the next year, mowing several times to control annual weeds. You could, instead, till in the clover in late spring or early summer to plant a food crop then.
Harvesting fall broccoli and cabbage
We harvest all our brassicas three times each week, and take the produce directly to our cooler.
Broccoli side shoots. Photo Nina Gentle
Our main broccoli harvest period is 9/10-10/15, with smaller amounts being picked either side of those dates We like our broccoli heads to get as large as possible (without opening up) before we harvest. We test by pressing down on the head with our fingertips and spreading our fingers. We harvest as soon as the beads start to “spring” apart. This may be a little late for other growers. We also look at the individual beads and aim to harvest before the beads even think about opening. We cut the stem diagonally to reduce the chance of dew and rain puddling, which can cause rotting of the stem. Later we harvest the side shoots, until they are too small to bother with.
A storage cabbage, with curled-back leaf on the head, showing maturity. Photo Bridget Aleshire
Cabbage heads up from 9/25 and holds in the field till late November. Cabbage is mature when the outer leaf on the head (not the outer plant leaves which are left in the field) is curling back on itself. For storage cabbage, we set the cut heads upside down on the stump, in the “basket” of outer leaves, and come back an hour later to gather them into net bags. This allows the cut stem to dry out and seal over, improving storability.
If you are already looking ahead to the fall, see my post Fall and Winter Vegetable Growing, Harvest and Storage, for lots of links to more info on season extension into cold weather; fall and winter vegetable harvests; and fall and winter vegetable storage. I will write more about other fall brassicas in the near future.
Our hoophouse with a December snowfall. Pam Dawling
We’re solidly in the darker and colder half the year for our monthly series of 14 Workhorse Crops (asparagus, beans, cabbage, carrots, chard, collards/kale, garlic, potatoes, sweet corn, sweet potatoes, tomatoes, watermelons, winter squash, zucchini/summer squash). These crops are reliable and productive under a range of conditions. You can use the search box to find previous month’s entries, such as December.
Winter is a natural opportunity to reconsider the size of your garden, which crops to grow, and your growing methods. Perhaps this will be your first gardening year? If so, welcome! Use the search box to find specific info, or click the blog category to find some further reading. Hopefully, we all have our garden plans made and our seeds ordered. Maybe we are already looking at a planting schedule.
In January, we can plant small small potato onions outdoors. We prepare the bed in the late fall and mulch it with hay, to plant in January. We rake off the mulch, plant the onion bulbs and then lay the mulch back on the bed, to control weeds and somewhat to insulate the little onion bulbs. These smallest potato onions are very cold-hardy, and will grow up to produce a single 3” (7.5 cm) large onion. A few will grow and subdivide to produce more small onions. Click the link to read the details.
Indoor sowings for later transplanting outside or in the hoophouse
In our greenhouse we fire up our germinator cabinets and sow our first lettuce and early cabbage (Early Jersey Wakefield and Faroa) and scallions in mid-January. The following week we sow our tomatoes to plant out in the hoophouse, and at the end of the month, spinach if we have not got enough sown in our hoophouse to transplant as bare-root transplants.
Flats of cabbage seedlings in our greenhouse. Photo Pam Dawling
Hoophouse workhorse crops to plant in January
In the hoophouse we are sowing a second or third round of crops, mostly successions of greens and radishes. We have already pulled our first and second radishes, and some of the Asian greens.
This March we will be using a half-bed in the hoophouse for some early green bush beans. Like our other warm weather crops, these can be planted in the hoophouse a month earlier than outdoors. Two cautions with green beans in the hoophouse: buy a very upright variety, as the plants will be more sprawling than they are outdoors. Outdoors we grow Provider and Bush Blue Lake (both very reliable and productive), and in the hoophouse we like Strike. The second bean caution is that we have found the edge beds too cold for beans when we need to sow them, in March. Don’t plant them now, but order seeds of an upright variety and plan a non-edge bed. I’ll say more in March.
We have also planned our next round of early warm-weather crops, which we will transplant in late March and early April. Tomatoes and zucchini/summer squash are on our Workhorse list
Young spinach seedlings. Photo Pam Dawling
We stop filling gaps in most of the Asian greens at the end of December, because they will start to bolt in January and/or because they are mature and we will be clearing the space to sow something else. Tatsoi, Tokyo Bekana, Pac Choi, Chinese Cabbage, Yukina Savoy, all need to be eaten during January. We sow spinach (the Racehorse Crop) in mid-January, to transplant in the hoophouse and outdoors.
Vates kale seedlings for bare-root transplanting. Photo Pam Dawling
On January 24 we sow Vates kale and Morris Heading collards in the ground in the hoophouse, in the space recently freed up by the Chinese cabbage. For 1080ft outdoors, we need 108ft of seedling rows. We can fit 14 rows of seedlings across a 4ft (1.2 m) bed.
See November’s information on Follow-On Crops, and Filler Greens (short rows of greens sown in October to fill unexpected spaces).
Workhorse Crops to Harvest in January
We still have workhorse crops to harvest outdoors: chard, kale and collards, and perhaps cabbages. We’re down to three of our 14 workhorse crops to harvest outdoors in January, but we have the Racehorse Crop, spinach, too, and also luscious hoophouse greens.
Deadon (105d winter cabbage) is extremely cold hardy – we leave it outdoors until nights threaten to hit 10°F (-12°C), the lowest temperature I’ve seen it survive. We just had one night at that temperature, much colder than anything else so far this winter.
Chard can still be harvested outdoors if we covered it with hoops and rowcover. The outdoor killing temperature for unprotected Bright Lights chard is 22°F (–6°C); red chard survives down to 15°F (–9.5°C) and green chard to 10°F (–12°C). We have succeeded in keeping chard alive outdoors right through the winter, if we cover it.
Collards and Kale can be lightly harvested in January. Our mnemonic for sustainable harvesting of leafy greens is “8 for later”, meaning we leave at least eight inner leaves when harvesting the outer ones, to ensure the plants have enough strength to regrow. In October, November, February and March, we can harvest leaves from these plants once a week. In December and January, once each month is more like what we can hope for. Chard and senposai do OK with only 6 leaves left.
Hoophouse Workhorse harvests in January
We are harvesting leaves from our hoophouse Bright Lights chard at an adolescent size, cutting them into ribbons, and chopping the colorful stems, for salad mixes. Later, when the days lengthen, we’ll be able to harvest leaves for cooking.
Red Russian kale in our hoophouse Photo Pam Dawling
The Red Russian and White Russian kales are ready to harvest now (we were a bit late with getting a successful sowing in September). Russian kales belong to the napus group of kales, which are better able to make growth in low light levels than oleracea types like the Vates we grow outdoors. Vates is our star outdoors, because it is more cold-hardy than any other kale I’ve found. The Russian kales have a tendency to wilt after harvesting, so we move fast and stand the leaves up in the buckets. We add some water to the buckets before rushing them to the walk-in cooler. (We do this with chard, turnip greens and Tokyo bekana too.)
The hoophouse senposai is on its third round of harvests, just two weeks after the second, which was one week after the first. This clearly demonstrated the slower rate of growth as temperatures and daylight decrease. The short days do cause plant growth to slow down, but this is not the only factor. Soil temperature is another. In our hoophouse, the soil temperature is still 50F (10C) in early January.
But hey! The length of daylight is now increasing! On the shortest day, December 21, we have 9 hours and 34 minutes of daylight, from 7.21 am to 4.55 pm. The mornings continue to get darker by a few minutes, taking a month to get back to 7.21, from a latest of 7.25 am. Meanwhile the evenings are getting lighter, gaining us 6 minutes by January 5. I’m typing this on my laptop onto a USB stick, as we are in day 3 of a power outage. I appreciate the lighter evenings! By January 21 we will be up to 10 hours of daylight!
Workhorse Crops from storage in January
Storage crops come into their own in December and January, once outdoor growth has slowed down. The flavor of stored sweet potatoes reaches its peak in late January! Besides the Workhorse Crops of carrots, potatoes, sweet potatoes, winter squash and garlic, there are many other root crops. See my posts Root Crops for the Month. Use hardneck garlic first, as it stores for only for 4-6 months. Softneck garlic can store for up to 7 months.
Eat up your acorn and other pepo types of winter squash, as they store for only 1-4 months. Maximas such as Cha Cha, Jarrahdale and Kabochas store for 3-5 months; Moschatas such as Butternuts and Cheese pumpkins will store for 8 months or even more. Seminole pumpkin can easily store for a whole year at room temperature. They do have hard shells and need a hefty cleaver to cut them open.
Our white potatoes are keeping well in the root cellar down at 40F-50F (5C-10C). We air it about once a week. We open the door on mild nights or chilly overcast days, depending what we get and what we need. Potatoes in storage after their first month are no longer respiring much at all. They should be dormant, and not in need of many air changes.
Sweet potatoes on a plate. Photo Brittany Lewis
Our sweet potatoes are very delicious. We are eating about 40-50lbs (19-23 kilos) a week.
Stored cabbage can also be a boon, and this is also a good time to explore all the pickles and canned and frozen produce you put up earlier.
Workhorse Crops Special Topics for January: Making Schedules.
We continue our Garden Planning, ordering seeds and planning schedules of field planting and greenhouse seedling starting. In January we start sowing seeds indoors, and need our schedule figured out for that. We also need to pay attention to germination temps for various crops, so that we get them off to a good start, matched with crops needing similar temperatures in each germination cabinet.
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.
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.
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
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 redvarieties.
·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 shadeof 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 cangrow 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.
Visit to Pelegrin Courtyard (Patio Pelegrin) artist family Community Agricultural Project (organoponico) in Pinar del Rio, close to Viñales, Cuba
Day 6 –Sunday January 12 (journey back to Havana)
This is the continuing story of my Agroecology Tour of Cuba with Organic Growers School in January 2020. Search the Cuban Agriculture Category for more posts about other farms we visited.
Our air-conditioned bus left at 8.30 am to visit Pelegrin Courtyard (Patio Pelegrin) artist family Community Agricultural Project (organoponico).
Pelegrin Patio artist community dolls, Cuba. Photo Pam Dawling
We were greeted by a group of children singing and performing a short sketch. Then we were given a tour, including a caged crocodile, guinea pigs (food?) a catfish pond (catfish are invasive aliens, which Cubans are trying to eliminate by eating them. [I wonder why they don’t feed them to tourists?]
Pelegrin Courtyard pond with turtles and catfish. Photo Pam Dawling
We saw their vegetables in beds edged with roof tiles. We saw field crops including sweet potatoes and coffee.
Again I saw cilantro and creole spinach. I’m still seeking other names for creole spinach.
Creole Spinach at Pelegrin Courtyard, Cuba. The blue fabric is for organic pest control. Photo Pam DawlingClose up of creole spinach in Cuba. Photo Pam Dawling
Creole Spinach is different from Egyptian spinach (Corchorus olitorius), Lalo, Molokheya, Saluyot, Ewedu, West African Sorrel, Krin Krin, Etinyung, Jute leaves. Also see more about Jute Leaves at this link. Note pointed leaves.
Nor is it New Zealand spinach (Tetragonia tetragonioides (previously T. expansa), Warrigal greens, kōkihi. That has succullent leavesthat are almost trinagular.
Learning about these hot weather greens may be useful as our summers get hotter.
I have a bit more information about the Cuban oregano,Plectranthus amboinicus, I saw at several farms, including AlamarUrban Organic Farm . Cuban oregano is a member of the mint or deadnettle family. It has characteristic thick, fuzzy leaves with a strong pleasant odor. The flavor of Cuban oregano is said to be much stronger than Greek oregano.
I also saw meprobromato, a herb drunk as a tea or cold drink to treat anxiety. Meprobromatewas manufactured and marketed in the US as Miltown and Equanil. They were best-selling sedatives/minor tranquilizers for a time, until replaced by benzodiazepines. Nowadays, meprobromate is known to be addictive at doses not much higher than the medication dosages.
Mosaic steps at Pelegrin Courtyard farm. Photo Pam Dawling
We saw many outdoor mosaics, including walkways, steps and pieces embedded in the walls.
Mosaic bench at Pelegrin Courtyard, Cuba. Photo Pam Dawling
Inside the galleries we saw pottery, dolls and paintings. I bought a painting of an old man for $25.
Pelegrin Courtyard pottery. Photo Pam Dawling
There was a big porch with a mural and greetings from groups who had visited from all over the world.
Porch on the artists’ gallery at Pelegrin Courtyard, Cuba. Photo Pam Dawling
They have received international support for some of their farming (irrigation) and their farm buildings.
Collards are a southern food icon and an underappreciated nutrition powerhouse that has sustained generations of southerners, both Black and white. At last this vegetable is getting the recognition it deserves! The first ever Collards Week is happening December 14-17 2020. I found out about this while researching for an article on collards for Growing for Market magazine. Yes, perhaps the title “Week” is aspirational, and four days is a jumping-off point for the post-Covid future.
There will be online presentations celebrating collards led by Michael Twitty, Ira Wallace, Jon Jackson, Amirah Mitchell and Ashleigh Shanti. This event includes food history, seed stewardship, gardening, farming, cooking and conversation and is part of the Heirloom Collard Project. Collards Week is a collaboration between the Culinary Breeding Network and The Heirloom Collard Project. You can register for free at www.heirloomcollards.org/collard-week-2020/. All events will be broadcast live through YouTube Live via the Culinary Breeding Network starting at 1:00pm Eastern time.
Chef Ashleigh Shanti preparing collards. Photo Chris Smith
Michael Twitty’s kick-off presentation, The History and Significance of Collards in the South, will be a fascinating exploration of complex issues. Twitty states this himself on his blog, Afroculinaria, “The collard’s complicated story with African Americans really speaks to the way food can unravel the mysteries of complex identities.”
The Collards Tour and the Book
From 2003 to 2007, a team of four crisscrossed the South, mostly in North and South Carolina, searching for heirloom collards by word-of-mouth, by spotting them as they drove past, and by reading newspapers, attending small-town collard festivals, and visiting restaurants where collards were the only greens served. After the trip, USDA Plant Geneticist Mark Farnham grew out more than sixty of the heirloom collard cultivars in a trial garden at a USDA Agricultural Research Station. He published several papers, including the 2007 article “Neglected Landraces of Collard from the Carolinas.”
Two of the other road trip members, Edward H Davis and John T Morgan of Emory & Henry College, wrote a beautiful book: Collards: A Southern Tradition from Seed to Tableto tell the stories of these varieties and the gardeners who steward them. Davis and Morgan noted that despite other wide diversity among the collard seed savers, most of them were older, with an average age of 70, and most of them had no family, friends, or neighbors willing or able to keep growing their special family collard variety into the future.
The Heirloom Collards Project
In 2016, Seed Savers Exchange in collaboration with Ira Wallace at Southern Exposure Seed Exchange requested over 60 collard varieties from the USDA ARS National Plant Germplasm System (NPGS) to trial at Seed Savers Exchange, Decorah, Iowa. These were rare heirloom varieties collected by Davis and Morgan from seed savers across the Southeast. The goal of the Heirloom Collards Project is to support the tradition of heirloom collards, by finding growers and sharing the seeds nationally and also to celebrate the special stories associated with these heirloom collards.
Ira Wallace has an article “A Southern Food Tradition: Saving Heirloom Collards” coming out in the Jan/Feb 2021 issue of Grit magazine. There she points out that giant seed companies have been buying out the smaller ones, and have reduced the number of open-pollinated collard varieties readily available to only five.Saving heirloom collards is an act in food heritage. Ira’s article also includes some collard stories and directions for growing seed. You can also find good directions for growing seed in Jeff McCormack’s Organic Brassica Seed Production Manual.
Mosaic photo by Chris Smith
The Heirloom Variety Trial
The National Heirloom Collard Variety Trial was launched in 2020, with over 230 participants across the US. They are currently growing twenty different varieties from the large collection at Seed Savers Exchange and the USDA. This collection includes varieties from the Davis and Morgan collecting trips. There areeight trial sites growing all 20 varieties and also hundreds of citizen scientists growing and comparing randomly selected sets of three varieties.The growers are recording data for each collard variety on appearance, uniformity, vigor, disease resistance, flavor, germination, earliness, yield and winter hardiness. Their data will be recorded and analyzed via SeedLinked, a web platform connecting people with information on varieties written by people growing them.
The Heirloom Collard Project has a place for everyone interested in growing or eating this delicious vegetable, including home gardeners, experienced seed savers, commercial growers and chefs. Click the link to see photos of the 2020 varieties and the farms doing the full trial. Get ready to sign up for 2021. Novice seed growers may want to consider practicing with more common varieties first, and then, as they gain experience, they can sign up to become seed-saving stewards.
Morris Heading collards. Photo Kathryn Simmons
Growing collards
Collards are very easy to grow and harvest, providing months of harvests from a single sowing. They are cold-hardy and heat-tolerant, giving the possibility of harvests ten months of the year in the Southeast. Colder areas may need to provide some protection if wanting mid-winter harvests. Hotter areas may need a longer summer break. Growers can make sauerkraut to extend the season. There is a wide range of leaf shapes and colors including variegated types. For details of how to grow collards, see my article coming soon in Growing for Market.
Collard stecklings overwintering in a pot for seed saving. Photo Seed Savers Exchange
There is a fascinating blog post published on the Heirloom Collard website written by Norah Hummel, who is a Seed Savers Exchange partner in the Heirloom Collards Project. It’s a really fantastic blog post with some really good photographs, talking you through the whole process of growing collard seed.
Growing Collard Seed
Like other brassicas, collards are a biennial seed crop. To save seed, keep your collard plants alive over winter. If you can’t do this outdoors or in a hoophouse, dig up the plants in late fall and trim off the leaves, preserving the growing point. Replant these plant stubs (stecklings) close together in a tub of soil or even damp sawdust, to replant in early spring. Make sure you have no other brassicas from the oleracea group (Brussels sprouts, cabbage, cauliflower, some kales, kohlrabi) in flower at the same time. Some kales (Russian, Siberian types) are Brassica rapa and do not cross-pollinate.
Winnowing collard seed with a box fan. Photo Southern Exposure Seed Exchange
Read Margaret Roach’s interview on A Way to Garden, with Chris Smith of Utopian Seed Project, a crop-trialing nonprofit working to celebrate food and farming, and Sow True Seeds, talking about heirloom collards.
Mosaic photo by Chris Smith
