Asian Greens for March: Yukina Savoy in the Hoophouse

Koji Yukina Savoy in late December.
Photo Pam Dawling

I wrote about outdoor Yukina Savoy going into the winter, in my October post. Re-read that to get details of days to maturity, cold-tolerance (10F/-12C outdoors) and the differences between the open-pollinated Yukina Savoy and hybrids such as Koji. Five months after that posting we are harvesting the last of the over-wintered Yukina Savoy in the hoophouse. For us, this is a cooking green, not a salad crop. It’s delicious and easy to cook. A little robust for salads, for most people.

Young Yukina Savoy plants in our hooophouse.
Photo Wren Vile

In March we are starting our hoophouse crop transition to early summer crops (tomatoes, peppers, squash, cucumbers) and meanwhile we are enjoying harvests of arugula, brassica salad mix, Bulls Blood beet greens, chard for salad and cooking greens, Russian kales, leaf lettuce, lettuce heads, baby lettuce mix, mizuna and frilly mustards, radishes, scallions, senposai, spinach, tatsoi, turnips and greens and yukina savoy.

We do two hoophouse plantings of Yukina Savoy: the first transplanted from outdoors on October 6, feeds us from December 5 to January 31. The second, transplanted from outdoors on October 24, feeds us from January 8 to early March, sometimes to mid-March. This spring several crops are bolting earlier than hoped-for! We have had some back-and-forth temperatures, which can trigger bolting. Among brassicas, Yukina Savoy is relatively heat-tolerant. This is part of why we do the second planting – it helps us extend the brassica season until we can harvest more outdoor kale.

We transplant Yukina Savoy at 12″ (30 cm) apart in the row, with 4 rows to a 4′ (1.2 m) bed. For a hundred people with lots of other vegetables available, we plant 60 in the first planting and 40 in the second. There are too many other crops competing for space in late October for us to plant more than 40.

Harvesting Yukina Savoy leaves in late November.
Photo Wren Vile.

Initially we harvest this crop by the leaf, until we see the stems start to elongate prior to bolting, when we cut the whole plant. (It is a loose head type of crop, so don’t wait for a firm head to form!)  Actually we pull first, then cut off the head, then bang two roots together to shed the soil, and put the pulled root stumps on the bed to dry out and die. This is easier than cutting first and pulling later. If they do bolt before we get round to pulling them, I have added the pretty yellow flowers to the salad mix. Like all other brassica flowers, these are edible.

Kitazawa Seeds tells us that Yukina Savoy is a Brassica rapa Pekinensis group, for those with a love of brassica botany and those saving seeds. Also those, like us, looking for nematode-resistant vegetables. Brassica juncea are the most resistant brassicas. Kitazawa classifies it as a loose head type of Chinese cabbage.

Yukina Savoy in the early morning mist.
Photo Wren Vile

Asian Green for February: Tatsoi

A large tatsoi plant in our hoophouse in December. Photo Kathleen Slattery

Tatsoi is a very cold-hardy green (down to 10°F, –12°C), one of the ones we grow in our hoophouse to feed us after the winter solstice, when the crops have started to be fewer in number and each is less abundant in production rate.  We have also grown this one outdoors in the fall for early winter eating, but no longer do this as the rate of growth inside the hoophouse is much better. In the fall tatsoi will not bolt, but in late winter/early spring it will.

I have been writing about a particular Asian green once a month since last May. To find the other articles, click the category “Asian Greens”.

Like Asian greens in general, tatsoi is a great crop for filling out winter CSA bags or market booths, and ultimately, dinner tables. Because the Asian greens are so varied in color, texture, shape and spiciness, you can add a lot of diversity to your crops by growing a selection that is easy to grow and can all be treated the same way. They are as easy to grow as kale. They germinate at a wide range of temperatures and make fast growth (much faster than lettuce in cold weather!)

Botanically, tatsoi is Brassica rapa var. narinosa, cousin of other turnip family greens such as Chinese cabbage, Tokyo Bekana, pak choy, mizuna and komatsuna. It is a more distant cousin of the Brassica oleracea greens such as Vates kale, Chinese kale and kai-lan, and of crops in the Chinese Mustard family, Brassica juncea (the frilly mustards like Ruby Streaks and Golden Frills).

Tatsoi is a relatively small plant with shiny, dark green spoon-shaped leaves and green-white stems. If given plenty of space it grows as a flat rosette, but if crowded it takes on a flowerpot shape. For sale, the whole plants are cut and the leaves banded together, so crowding them does not at all make them less marketable. It has a pleasant mild flavor.

Young tatsoi plants in our hoophouse.
Photo Bridget Aleshire

Growing Tatsoi

We direct sow and then thin into salad mixes, leaving some to mature at 10″ (25 cm) across for cooking greens.  You can also transplant at 3-4 weeks of age in the fall, at 6″ (15 cm) apart. Although we transplant most of our brassicas, to allow the beds more time without this crop family (which we grow lots of), we direct sow this one, which will have many plants in a small space.

Tatsoi has similar care requirements to other brassicas. Very fertile soils grow the best Asian greens, so turn in leguminous cover crops or compost to provide adequate nutrition. Asian greens are shallow rooted – Pay extra attention to providing enough water to prevent bitter flavors and excess pungency. Expect to provide 1” (2.5 cm) of water per week in cooler weather, 2” (5 cm) during very hot weather.

Do close monitoring for pests, which can build up large populations during late summer. We do nothing special for our tatsoi, but if you have a lot of brassica flea beetles or uncontrolled caterpillars, cover the sowings or new transplants with insect netting such as ProtekNet.

If you are growing tatsoi outdoors in late fall, you could use rowcover to keep your plants alive longer into the winter.

For our hoophouse, we make a first sowing of tatsoi in the very first bed we prepare for winter crops, on 9/6. We make a second sowing in mid-November. The first sowing will feed us for two months, November and December.  The second sowing will feed us for a much shorter period of time: the second half of February, first week of March. It would bolt if we tried to keep it any longer.

It is entirely possible to make sowings between 9/6 and 11/15, and get harvests that last longer than our 11/15 sowing. The only reason we don’t is that we have so many other crops we love.

Kitazawa Seeds have a Red Violet tatsoi/pak choy hybrid, with an upright habit. They classify tatsoi as a type of pak choy/bok choy/pak choi, so if you are perusing their interesting site, this is how to find tatsoi.

Tatsoi ready for harvesting of whole plants.
Photo Pam Dawling

Harvesting Tatsoi

Tatsoi takes 21 days to be big enough for baby salads; 45 days for cooking size.

To harvest, initially we thin the rows to 1″ (2.5 cm), using baby plants in salad mix. Our first sowing provides thinnings from 10/8, one month after sowing. Next we thin to 3″ (7.5 cm), using these also for salad. Our next thinning, to 6″ (15 cm) gives us small plants for cooking. After this, we harvest individual leaves for salad or cooking. The second sowing provides thinnings 12/27-1/21 approximately.

Once we get close to the time the plants would bolt, we pull up whole plants and use them for cooking. We pull the most crowded plants first, giving the others time to grow bigger – they can grow as big as 12″ (30 cm) across. Overcrowding can lead to early bolting.

Overview of Winter Hoophouse Greens

In the big scheme of things, we harvest Tokyo Bekana and Maruba Santoh for heads in December, along with our first tatsoi; our first Yukina Savoy, our Chinese cabbage and Pak Choy in January, our second tatsoi and Yukina Savoy in February and early March.

Non-heading leafy greens such as Senposai, spinach and chard feed us all winter until mid-March when we need the hoophouse space for spring crops. (Read more about Yukina Savoy here in March.)

After Tatsoi

We clear our first tatsoi by 1/14, and use the space to sow our fifth spinach on 1/15. This planting of spinach is to be used as bare root transplants outdoors in March. Our second tatsoi is cleared 3/12 to prepare the space for early summer crops like tomatoes, peppers, beans, squash and cucumbers.

Beauty in a tatsoi plant.
Photo Wren Vile

Spinach Variety Trials and Planting Plan

Avon spinach in our hoophouse October 25.
Photo Pam Dawling

For years we grew only Tyee savoyed spinach. It did very well for us in central Virginia. It survived our zone 7a winters outside under rowcover. It could survive without the rowcover, but given that spinach makes growth whenever the air temperature is above 40F, and that the air under rowcover reaches that a lot more often then the air outside, we got much more growth using rowcover. We also got much better quality leaves, as they didn’t get battered by the weather.

Tyee is bolt-tolerant too but tended to yellow, slightly tough, leaves in the fall.

Tyee was dropped as a variety by the growers because (as I understand it) it suffered from a disease that is prevalent in the Pacific Northwest, where spinach seed is grown. It’s a hybrid, so we can’t just save our own seeds. We set out to try other varieties in order to find something to replace our beloved Tyee.

I wrote about spinach varieties here  in October 2016.

We tried Chevelle and Avon. Chevelle didn’t do that well for us. Part of the problem was poor germination, which could have just been that one packet of seed. But the pressure was on to find a productive variety, so we gave up on Chevelle.

We strongly prefer savoyed spinach over flat leaf spinach, because it has more loft in salad mixes and is more wilt-resistant after harvest. Apparently the East coast prefers savoyed spinach and the West coast the flat leaf kind, for what that’s worth. And of course, that takes no account of the millions of people between the coasts!

Reflect spinach from a September 12 sowing, outdoors under rowcover after the -9F night in early January.
Photo Pam Dawling

Next we tried Avon and Reflect, and they seemed pretty similar, both have good flavor.

Avon (42 days mature, 20 to baby leaf) semi-savoyed F-1 hybrid with upright growth, Fedco likes Avon as a replacement for Tyee, but cautions

“We found Avon’s DM [Downy Mildew] resistance is not adapted to overwintered protected culture. Otherwise resistant to DM1,2 and CMV [Cucumber Mosaic Virus].”

Sounds like it might not do as well if water supplies run short once it gets hot. Bolting is initiated by heat, crowding and day-length over 14 hours. Avon claims strong bolt resistance.

Reflect (38 days to mature) semi-savoyed hybrid is recommended by Johnnys as a good alternative to Tyee. It has much more resistatnce to various Downy Mildew strains (1-11, 13, 15, 16), but is “slightly” faster bolting than Tyee. This factor could be set against its very fast growing rate. Its color is a medium-green, less dark than some other varieties.

This winter and spring we are trying Avon, Reflect, Renegade, Escalade and Acadia.

Renegade (43 days mature) smooth leaf hybrid. Slower growing than Corvair, which it resembles in flavor. Does well in chilly damp conditions (our winter hoophouse?) Has resistance to DM 1-7. Bolt-resistant, dark green leaves.

Escalade (43 days mature) slightly savoyed hybrid, with upright growth, claims high bolt resistance. Resistant to DM 1-14, 16. Slower growing than some. Expected to handle temperature and light variability. Good for baby leaf production (not what we do). The flavor is mild (not a good thing, for those of us who love spinach!) Will it grow fast enough in our short springs to give high yields before it bolts? We’ll let you know.

Acadia (45 days mature) slightly savoyed hybrid with upright growth. Resistant to DM 1-13, 15, 16. Even slower growing than Escalade, even more suited to baby leaf production

Our second sowing of hoophouse spinach. Left row Avon, then Acadia, then Escalade, with Renegade nearest the plastic. Sowed 11/8, photographed 2/5.
Photo Pam Dawling

Paul and Sandy Arnold in Argyle, New York, made a great slide show reviewing  Spinach Varieties in High Tunnels

The winners (in order) in terms of yield were Pigeon, Space, Giant Winter, Tyee, Palco. These were followed, after a noticeable drop in yield, by Raccoon, Renegade, Donkey, then another noticeable drop to Corvair, Regiment, and a plummet to Bloomsdale Longstanding and Samish. Giant Winter and Bloomsdale Longstanding are the only OPs in the list. We grew Giant Winter once. It did grow enormous leaves, but was very quick to bolt. Unsuited to repeated harvests in our climate.

In 2011-2012, High Mowing Seeds in northern Vermont did a spinach variety trial with 24 varieties, assessing productivity, color and harvest time. The 24 varied a lot in earliness, upright growth habit or not, flat or savoyed leaves, and level of pest resistance.

On color, America, Corvair, Crocodile, Donkey, Emilia, Lazio, Menorca, Queen, Raccoon, Red Kitten, Regiment, Samish, Seven Green, Space, Spargo, St Helens and Tyee scored 7 out of ten or better. Tyee only scored 7, Reflect only 4-5. The best were Corvair and Crocodile.

  • Corvair had a good color and upright growth (clean leaves, easy to pick).
  • Donkey was dark and productive.
  • Emu was an early producer with a better color,
  • Giant Winter was a great early producer although poor on color (and terrible on bolt-resistant when we grew it in Virginia).
  • Lombardia was good on yield and flavor,
  • Raccoon was one of the easiest to pick,
  • Red Kitten (red stems) was pretty and heavy but not high yielding,
  • Reflect was a good survivor in heavy rains,
  • Regiment gave high yields and had a good green color.
  • Space was one of the highest for yield,
  • Samish was good on yield and OK to pick,
  • Tyee had good savoy-ness but lower yield, although many other good points.

Our first sowing of spinach in the hoophouse, photographed in late September. Reflect on the left, Avon on the right.
Photo Pam Dawling

Here’s our spinach planting plan:

We are able to keep harvesting spinach from October 15 to May 25, all the way through the winter.

September 6 is our first sowing (sprouted seeds) in the hoophouse for winter harvest 10/30-2/15,

We sow outdoors on September 7 (sprouted seeds) for growing under rowcover and harvesting in fall and winter,

September 18-20 we sow in our coldframes and outdoors for harvest in early spring, until late May,

October 24 we make our second hoophouse sowing, to feed us November 25 to May 7. In 2017, we failed to water this planting enough, and had to resow November 8.

November 9  we make a third hoophouse sowing, intending to use these plants to fill gaps in our hoophouse as other winter crops come to an end.

January 16 we make more sowings in the hoophouse, some to continue to fill gaps there along the edges of the beds where they won’t fight with the tomatoes and so on, which we transplant starting March 15.

Most of the spinach sown this date is for transplanting outdoors February 21.

January 29 we sow in flats in the greenhouse if we see we haven’t got enough bare-root transplants in the hoophouse.

If we don’t have enough transplants, then on February 10 we sow outdoors with rowcover, for spring harvests until May 25 if we’re lucky. We have backup plans on backup plans for this!

In the hoophouse we continue transplanting spinach to fill gaps until March 31.

Hoophouse spinach #2. Front row (bottom of the picture) Acadia then Escalade then Renegade.
Photo Pam Dawling


Winter-Kill Temperatures of Cold-Hardy Vegetables 2018

Here’s the long version of one of the slideshows I presented on January 13 at the Future Harvest CASA conference. Since I got home, I updated my Winter-Kill Temperatures list, which appears in the slideshow. Compared to my list for 2016, there are a few differences, nothing major. We had some extremely cold weather, as I reported last week with some sorry pictures of lettuces. Now I have some photos of the outdoor crops too. The Vates kale had mixed survival, the rowcovered Reflect and Avon spinach are damaged but OK, the Tadorna leeks are battered but hanging in there (so are we!).

Vates kale which survived temperatures of -8F and -9F outdoors, uncovered.
Photo Pam Dawling

Vates kale with a freeze-killed center January 19 2018.
Photo Pam Dawling

For several years I have been keeping records of how well our crops do in the colder season. I note each increasingly cold minimum temperature and when the various crops die of cold, to fine tune our planting for next year. We had some extremely cold temperatures of -8°F and -9°F (-22°C and -23°C) in early January 2018. We are in zone 7a, with an average annual minimum temperature of 0-5°F (-18°C to -15°C).

Unless otherwise stated, these are killing temperatures of crops outdoors without any rowcover. All greens do a lot better with protection against cold drying winds. Note that repeated cold temperatures can kill crops that can survive a single dip to a low temperature, and that cold winds, or cold wet weather can destroy plants quicker than simple cold. Your own experience with your soils, micro-climates and rain levels may lead you to use different temperatures in your crop planning.

Hoophouse Notes

Our double-skin hoophouse keeps night time temperatures about 8F (4.5C) degrees warmer than outdoors, sometimes 10F (5.5C) warmer. Plus, plants tolerate lower temperatures inside a hoophouse. The soil stays warmer and the plants recover in the warmer daytime conditions (it seems to be the night+day average temperature that counts).

In the hoophouse (8F warmer than outside) plants without extra rowcover can survive 14F colder than they could survive outside; 21F colder than outside with rowcover (1.25oz Typar/Xavan).

For example, salad greens in a hoophouse can survive nights with outdoor lows of 14°F (-10°C) without inner rowcover. 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. Bright Lights chard got frozen leaf stems.

Lettuce hardy enough for a solar heated winter hoophouse in zone 7a (hardiest are in bold): Buckley, Ezrilla, Green Forest, Green Star, Hampton, Hyper Red Rumpled Wave, Marvel of Four Seasons, Merlot, New Red Fire, North Pole bibb, Outredgeous, Pirat, Red Cross bibb, Red Sails, Red Salad Bowl, Red Tinged Winter, Revolution, Rouge d’Hiver, Salad Bowl, Sylvesta bibb, Tango, Winter Marvel, Winter Wonderland.

35°F (2°C):  Basil.

32°F (0°C):  Bush beans, cauliflower curds, corn, cowpeas, cucumbers, eggplant, limas, melons, okra, some Pak Choy, peanuts, peppers, potato vines, squash vines, sweet potato vines, tomatoes.

27°F (-3°C): Many cabbage varieties, Sugarloaf chicory (takes only light frosts).

25°F (-4°C): Some cabbage, chervil, chicory roots for chicons, and hearts, Chinese Napa cabbage (Blues), dill (Fernleaf), endive (Escarole more frost-hardy than Frisée), some fava beans (Windsor), annual fennel, some mustards (Red Giant, Southern Curled) and Asian greens (Maruba Santoh, Mizuna, most Pak Choy, Tokyo Bekana), onion scallions (some are much more hardy), radicchio.

Spinach under rowcover, with our hoophouse in the background – crop protection pays!
Photo Pam Dawling

22°F (-6°C): Some arugula (some varieties are hardier), Bright Lights chard, large leaves of lettuce (protected hearts and small plants will survive colder temperatures), rhubarb stems and leaves.

20°F (-7°C): Some beets (Bulls Blood, Chioggia,), broccoli heads (maybe OK to 15F), Brussels sprouts, some cabbages (the insides may still be good even if the outer leaves are damaged), celeriac, celtuce (stem lettuce), some head lettuce, some mustards/Asian greens (Tendergreen, Tyfon Holland greens), flat leaf parsley, radishes (Cherry Belle), most turnips (Noir d’Hiver is the most cold-tolerant variety).

Large oat plants will get serious cold damage. Oats seedlings die at 17°F (-8°C)

Canadian (spring) field peas are hardy to 10-20°F (-12 to -7°C).

15°F (-9.5°C): Some beets (Albina Verduna, Lutz Winterkeeper), beet leaves, some broccoli, some cabbage (Kaitlin, Tribute), covered celery (Ventura), red chard, cilantro, endive, fava beans (Aquadulce Claudia), Red Russian and White Russian kales, kohlrabi, some lettuce, especially medium-sized plants with 4-10 leaves (Marvel of Four Seasons, Olga, Rouge d’hiver, Tango, Winter Density), curly leaf parsley, rutabagas (American Purple Top Yellow, Laurentian) if not covered, broad leaf sorrel, most covered turnips, winter cress.

12°F (-11°C): Some beets (Cylindra,), some broccoli, Brussels sprouts, some cabbage (January King, Savoy types), carrots (Danvers, Oxheart), most collards, some fava beans (mostly cover crop varieties), garlic tops if fairly large, most fall or summer varieties of leeks (Lincoln, King Richard), large tops of potato onions, covered rutabagas, Senposai leaves (the core of the plant may survive 10°F/-12°C), some turnips (Purple Top).

10°F (-12°C): Covered beets, Purple Sprouting broccoli for spring harvest, a few cabbages (Deadon), chard (green chard is hardier than multi-colored types), some collards (Morris Heading can survive at least one night at 10F), Belle Isle upland cress, some endive (Perfect, President), young Bronze fennel, probably Komatsuna, some leeks (American Flag, Jaune du Poiteau), some covered lettuce (Pirat, Red Salad Bowl, Salad Bowl, Sylvesta, Winter Marvel), covered winter radish (Daikon, China Rose, Shunkyo Semi-Long survive 10°F/-12°C), large leaves of savoyed spinach (more hardy than flat leafed varieties), Tatsoi, Yukina Savoy.

Oats cover crop of a medium size die around 10°F (-12°C). Large oat plants will die completely at 6°F (-17°C) or even milder than that.

5°F (-15°C): Garlic tops even if small, some kale (Winterbor, Westland Winter), some leeks (Bulgarian Giant, Laura), some bulb onions, potato onions and other multiplier onions, smaller leaves of savoyed spinach and broad leaf sorrel. Many of the Even’Star Ice Bred greens varieties are hardy down to 6°F (-14°C), a few unprotected lettuces if small (Winter Marvel, Tango, North Pole, Green Forest).

Tadorna leeks, struggling but not dead, after -9F.
Photo Pam Dawling

0°F (-18°C): Chives, some collards (Blue Max, Winner), corn salad (mache), garlic, horseradish, Jerusalem artichokes, a few leeks (Alaska, Durabel, Tadorna); some bulb onions, yellow potato onions, some onion scallions, (Evergreen Winter Hardy White, White Lisbon), parsnips (probably even colder), salad burnet, salsify (?), some spinach (Bloomsdale Savoy, Olympia, Tyee). Walla Walla onions sown in late summer are said to be hardy down to -10°F (-23°C), but I don’t trust below 0°F (-18°C)

Crimson clover is hardy down to 0°F (-18°C) or slightly colder

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

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

-10°F (-23°C) Austrian Winter Field Peas and Crimson clover (used as cover crops).

-15°F (-26°C) Hairy vetch cover crop – some say down to -30°F (-34°C)

-20°F (-29°C) Dutch White clover cover crops – or even -30°F (-34°C)

-30°F to -40°F (-34°C to -40°C): Narrow leaf sorrel, Claytonia and some cabbage are said to be hardy in zone 3

-40°F (-40°C) Winter wheat and winter rye (cover crops).

A cover crop of winter wheat untroubled by -9F.
Photo Pam Dawling

Cold-tolerant lettuce and the rest

Good survival of Green Forest and Revolution lettuce (sown September 24) in our hoophouse after the Big Freeze, on January 10.
Photo Pam Dawling

We keep a list of lettuce varieties for each season. We had extremely cold weather at New Year, -3F on Jan 2 and Jan 3, followed by -8F on Jan 6 and -9F on Jan 7. In past years we did not often need to add inner rowcover over our crops in the hoophouse at night, but in recent years, this has become more common. Our guideline is that if we expect the night-time low to be 8F or lower, we use rowcover. This winter, even with rowcover, we lost some lettuce and pak choy. Here are some before (December 20) and after (January 10) photos and notes.

Merlot lettuce on December 20.
Photo Pam Dawling

Merlot lettuce from our September 15 sowing on January 10.
Photo Pam Dawling

Merlot is one of our favorite reds and previously we regarded it as one of our more hardy varieties. Other ones from last year’s list of hardy varieties include Green Forest, Hyper Red Rumple Wave, Tango, Winter Marvel and Red Tinged Winter.  Hyper Red Wave (as we call it for short) didn’t do so well either.

Hyper Red Rumple Wave from our September 15 sowing, on January 10.
Photo Pam Dawling

Nor did Outredgeous from the earlier sowing, although the later sowing did better – the plants were smaller. Often smaller (younger, not stunted!) plants can survive colder temperatures.

Outredgeous lettuce from our September 15 sowing, on January 10.
Photo Pam Dawling

Outredgeous lettuce from our September 24 sowing still alive but with some damage on January 10.
Photo Pam Dawling

The real stars of red lettuce for cold-hardiness this winter have been Revolution from Fedco Seeds and Buckley from High Mowing.

Revolution lettuce in the foreground, Buckley in the background, on January 10.
Photo Pam Dawling

Another big star is Red Tinged Winter from Fedco Seeds. That’s the one I harvested leaves from on January 10.

Red Tinged Winter lettuce from our Septemebr 24 sowing in our hoophouse on January 10.
Photo Pam Dawling

Tango lettuce from our September 24 sowing on January 10.
Photo Pam Dawling

And, for green lettuce, Tango, also from Fedco, came through, as always.







Green Forest lettuce from our September 15 sowing on January 10.
Photo Pam Dawling

Our Green Forest romaine had mixed results. Once again the bigger, older sowing survived less well.

The same Green Forest lettuce on December 20. Photo Pam Dawling

Hampton lettuce from our September 24 sowing. One plant has collapsed with sclerotinia lettuce drop.
Photo Pam Dawling

Other green lettuces include Hampton and Ezrilla, two more of High Mowing’s Eazyleaf lettuce varieties. Not as hardy as their red Buckley, but not as wimpy as some. The older sowing of Hampton died, but the younger (seen here) mostly survived. We did not have any Ezrilla in our later planting. Now I wish we had, as I like this lettuce.

Ezrilla lettuce from our September 15 sowing on January 10. The damage was quite variable.
Photo Pam Dawling





Remember that these lettuces have been through very cold temperatures. That any survived is remarkable. We will learn from this and adjust our variety list before next winter!

Garden Planning, Winter Harvests and Speaking Events

Garden Planning Field Manual
Photo VABF

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

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

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

Hoophouse December View
Photo Kathleen Slattery

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

Hoophouse scallions ready to harvest.
Photo Pam Dawling

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

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

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

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

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

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

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

Year Round Vegetable Production, speaking events

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

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

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

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

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

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

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

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

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

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

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

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

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

February 7-10, 2018 Pennsylvania Association for Sustainable Agriculture, Farming for the Future Conference, State College, PA  I’ll be presenting three workshops:

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

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

Cover Crops for Vegetable Growers Saturday 8.30 – 9.50 am

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

Fall and Winter Hoophouses Saturday Feb 10 12.50-2.10pm

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

There will be handouts for each workshop and book signing

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

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

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

For the New Farmer Track: Cover Crops for Vegetable Growers

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

Sustainable Farming Practices 

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

April 12, 2018, 9am to noon,

Louisa Master Gardener Group Tour of Twin Oaks Gardens

Asian Greens for December: Pak Choy

Pak Choy in the hoophouse in December.
Photo Ethan Hirsh

December and the first three weeks of January are the season we harvest mature pak choy heads in our hoophouse. Pak choy, also known as bok choi, pac choy, and similar names, is a large 12″-15″ (30–38 cm) tall heading green, usually cut as a full head. If you prefer, you can harvest a leaf or two from each plant each time you want to eat some. It is hardy at least down to 32F (0C) outdoors. Some varieties are hardy down to 25F (-4C).

Botanically, pak choy is a Brassica rapa var. chinensis. If you plan to grow seed of more than one Asian green, carefully choose ones that won’t cross. Be aware of the possibility of brassica crops being wrongly classified.

Pak Choy in the hoophouse in early November.
Photo Pam Dawling

Pak Choy generally has thick rounded white stems, dark glossy leaves and a mild flavor. There are varieties with green stems, some with red-purple leaves such as Red Choi from Kitazawa, and some miniature varieties, such as Mei Qing Choi from Kitazawa, but we grow the full-sized white and green kinds, such as Joi Choi from Johnny’s and Prize Choy from Fedco. For the most choice, go to Kitazawa Seeds, as they stock 23 varieties (although 4 are tatois).

Like all Asian greens, pak choy is nutritious as well as tasty. It’s high in carotenoids, vitamins A and C, calcium, iron, magnesium and fiber. It contains antioxidants which fight against cancer and protect eyes from macular degeneration.

Brassica seedbed protected from insects with ProtekNet and hoops.
Photo Bridget Alsehsire

We sow for this planting in an outdoor nursery seedbed on September 15, and cover the outdoor seedbeds with insect netting. The ideal germination temperature range for Pak Choy is 45-70F, it’s very easy-going. Ideal  temperatures for growth are 60-70F. Hoophouses are perfect. The plants grow fast and we only get a few weeds to deal with.Asian greens have similar care requirements to other brassicas, and very fertile soils grow the best Asian greens.

We transplant as bare root transplants into the hoophouse just 3 weeks after sowing, around Oct 3. We plant 10″ apart, with 4 rows in a 4ft wide bed. We reckon on 52 pak choy plants for 100 people. Because the harvest period is short, it is not wise to grow too many.

Young Pak Choy transplants.
Photo Bridget Aleshire

Pak choy is shallow rooted, so pay extra attention to providing enough water during hot weather , 1” (2.5 cm) of water per week; 2” (5 cm) during very hot weather. This will prevent bitter flavors and excess pungency.

Do closely monitor for pests, which can cause havoc. We have had trouble in the hoophouse from the vegetable weevil larva. Click the link for information and great photos from Debbie Roos at Growing Small Farms. Other possible pests include flea beetles, aphids, harlequin bugs, cabbage caterpillars, grasshoppers and slugs.

Only about 8 weeks after transplanting, pak choy is ready to harvest. Because we want to keep all our hoophouse space in full use, we pull the plant out, then cut off the root. This is easier than cutting the head off at ground level, then trying to pry out the root.

Young Pak Choy plants in early November, with some darker Yukina Savoy on the right.
Photo Wren Vile

That same day we fill the gaps with some younger transplants (sown 10/10 in the hoophouse), that we have in reserve. We call these “filler greens.” We stop filling gaps with Asian greens (and lettuces) on Jan 25, and follow the pak choy with a sowing of kale to be transplanted outdoors in early March.

There’s a good publication from Iowa State Extension on  Commercial Production of Pak Choi. As an organic grower, I don’t use the herbicides and pesticides they mention, but the publication is good on identifying pests and diseases as well as covering the basic growing needs.

See ATTRA’s Cole Crops and Other Brassicas: Organic Production for more information than I can cover here.

In areas with cool or mild springs, pak choy can be a spring green, but that doesn’t work with our short springs – they just bolt rather than size up. Growing outdoors for fall harvest and in the hoophouse for winter use works best here in central Virginia.

Cold nights, Cool season hoophouse crops, CASA conference

Ginkgo Golden Puddle Day
November 10 2017.
Photo Pam Dawling

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

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

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

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

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

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

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

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

November hoophouse lettuce bed.
Photo Wren Vile

Making baby salad mix

Salad Mix freshly harvested.
Photo Pam Dawling

Our salad mix season has started! Very exciting! During the summer we have heads of lettuce and the warm weather salad crops like tomatoes and cucumbers. But now we’ve had a couple of frosts and we are starting to harvest mixed salads, mostly from our hoophouse. This involves snipping the outer leaves of various crops into ribbons, cutting small individual leaves from other crops and mixing the ingredients. In the photo above are spinach, Tokyo Bekana, Bull’s Blood beet leaves and a speck of Ruby Streaks. There is no lettuce in the picture. In October and early November we harvest the last of our outdoor lettuce and mix that in.

Tokyo Bekana in our hoophouse in late October.
Photo Pam Dawling

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).

Ruby Streaks and mizuna.
Photo Kathleen Slattery

I prefer to harvest and chop as I go, mixing everything at the end. It might seem easier to harvest first and then cut and mix, but that requires handling the greens a second time which causes more damage. Incidentally, tearing damages more  than cutting, so just get a good pair of scissors and keep them sharp. I cut and gather until I have a handful of leaves, then roll them lengthwise and cut into ribbons. The width of the ribbon depends on the crop. I like to have different size shreds. Mild flavor and plentiful items I cut on the wider side, stronger flavors narrower. I also want every bowlful to get some red highlights, so if red leaves are in short supply that day, I cut those thin.

Bull’s Blood beet greens in our hoophouse in late October.
Photo Pam Dawling

Use knives to cut whole heads, if you are doing that. Ceramic or serrated plastic knives cause less rapid browning to cut leaf edges, but almost all growers I know use metal knives.

Brassica salad mixes are easy to grow. There are various mustard mixes you can buy, to complement your baby lettuce mix. It doesn’t work well to mix lettuce seed and brassica seed together when sowing, as the crops grow at different rates. It is better to grow separate patches and customize your mix when you harvest. Wild Garden Seed has Wild Garden Pungent Mix, and the mild Pink Petiole Mix. Some seed companies now sell individual crops for mixes (see Johnnys Selected Seeds or Fedco Seeds Asian Greens for example). We mix our own Brassica Salad Mix from leftover random brassica seeds. For a single cut, almost all brassicas are suitable, except very bristly turnips. We sow in early February for March and early April harvests. Even if you don’t plan to grow brassica salad mix, keep it in mind as a worthwhile backup plan if other crops fail, or outdoor conditions are dreadful and you need a quick crop to fill out what you have.

Our first sowing of brassica salad mix, ready to harvest in mid-October.
Photo Pam Dawling

To harvest baby lettuce mix or brassica salad mix (also called mustard mix), use scissors, shears or a serrated knife, and cut an inch (a few centimeters) above the soil to spare the growing point of the plants for regrowth. Some growers use a leaf rake to pull out debris after each harvest of baby leaf lettuce, and minimize the chance of including bits of old rotting leaves in the next cut. For small plants, it works fine to pinch off individual leaves, provided you are careful not to tug–small plants may not be very firmly anchored in the soil! Small leaves can go in the mix whole

Young lettuce mix growing in our hoophouse.
Photo Ethan Hirsh

Baby lettuce mix can be cut 21 days from seeding in warm weather, but from November to mid-February, it may take two or three times as long from sowing to first harvest. Cool season lettuce mix may provide four or more cuttings, but in warm weather it will only provide a single harvest. Excessive milkiness from the cut stems is a sign of bitterness. You can also test by nibbling a piece of leaf. Our winter salad mixes end at the end of April, when our outdoor lettuce heads are ready for harvest.