Yukina savoy – Sustainable Market Farming

Nematode-resistant food crops and cover crops

Golden Frills and Scarlet Frills, two Juncea mustards that resist nematodes. Photo Pam Dawling

A few weeks ago I wrote about clearing tomato plants, and mentioned our hoophouse troubles with nematodes. Nematodes are tiny soil-dwelling worms that have a wide host range and are hard to control. They move only 3’–4′ (1–1.2 m) per year on their own, but people move them on shoes, tools, etc. We have had peanut root-knot nematodes (Meloidogyne arenaria) since 2011 when we found them in spinach transplants we were growing for outdoors in early spring.

My article on nematodes in Growing for Market in November 2014 describes our discovery of the beasties and our first attempts to deal with them.

White Russian kale in our hoophouse.
Photo Pam Dawling

In my August 2014 post Good news – great hoeing weather! Bad news – more nematodes in the hoophouse I wrote about solarization to fight nematodes in our hoophouse (scroll down to the end of the post). The post includes a photo of our first attempt at solarizing – a bit of a How Not To! Be sure to use UV-inhibited polyethylene. This year we somehow got some construction plastic mixed in. It doesn’t work! It goes cloudy (thus not heating up the soil) and it shatters into little pieces.

There is info on dealing with nematodes from Garry Ross in Hawaii, where nematodes are a fact of daily life, in my post Cold weather, snow, thinking about nematodes from February 2015.

My most thorough blogpost about nematodes was in 2018 for Mother Earth News: Managing Nematodes in the Hoophouse.

Solarizing with clear plastic. Photo Pam Dawling

My post Solarization and crop choices to fight nematodes in August 2019 includes a photo of a much better way to solarize an individual bed. In that post I gave a list of nematode-resistant food crops, and also talked about cover crops. There is a photo of nematodes on cucumber roots there too).

Food crop choices to fight nematodes

Most resistant and most helpful are the Juncea group of mustards. I did some research into more Juncea options in Solarization and crop choices to fight nematodes. We don’t like very pungent greens, so we have not yet taken the route of planting a whole bed of Juncea types. Instead we have mapped and flagged the nematode-infested areas of our beds, and try to be mindful of what we plant in those spots. Three of our seven beds have no nematodes so far.

Open-pollinated Yukina Savoy.
Photo Ethan Hirsh

This year we looked at the nematode map we had made and decided to focus our attention on the bed with the highest number of nematode patches, and grow the most resistant winter crops (of the ones we like to grow) there. That’s the frilly mustards (Ruby Streaks, Scarlet Frills, Golden Frills, all Juncea mustards, and Mizuna, a Japonica mustard), Yukina Savoy (variously reported to be Brassica juncea, Brassica rapa pekinensis, and Brassica rapa), and Russian kales (Brassica rapa).

Mapping nematode areas

See the post with info from Gerry Ross I mentioned above. We have previously tried for a “Two years good, One year bad” strategy. This was to grow nematode-resistant crops in the infected areas for two years, then try risking one year of susceptible crops. That was a bit demanding on careful management, and we haven’t kept that up.

Nematode map 2022

Cover crop choices to fight nematodes

French marigolds and sesame to deter Root Knot nematodes in our hoophouse. Photo Pam Dawling

A reader asked about cover crop choices to fight nematodes. In June 2019 I wrote about using marigolds, sesame, Iron and Clay cowpeas as warm-weather nematode resistant cover crops. We’ve also used winter wheat (in winter!), and white lupins (not worthwhile, in my experience). See that post for a few other ideas on nematode-fighting cover crops, and why we decided against some options. At that time, we decided not to grow sunnhemp (Crotolaria) because it is poisonous, although newer varieties of Crotolaria have lower toxin levels. More recently we have been growing sunnhemp, after I saw it growing so well in North Carolina. It is a warm-weather legume, so it is feeding the soil while tackling the nematodes. It does grow tall in the hoophouse, and we have taken to chopping it down with hedge shears to an ergonomic elbow-height every few weeks whenever it gets too tall. The cut tops create a nice “forest-floor” mulch effect. You can almost feel the extra organic matter nurturing the soil! (High OM levels deter nematodes.) 60-90 days to maturity.

Sunnhemp cover crop at Nourishing Acres Farm, NC.
Photo Pam Dawling

We previously used soybeans as a short-term leguminous summer cover crop, but they do not offer the nematode resistance. Iron and Clay, Mississippi Silver and Carolina Crowder cowpeas are all nematode-resistant and can be grown in summer instead of soybeans. Sesame is a legume that is particularly good against peanut root-knot nematodes.

Iron and Clay southern peas flowering in September. Photo Pam Dawling

See Our Organic Integrated Pest Management post for an organized approach to pest management, including nematodes.

A Florida reader gave me information about partridge peas, which I have not yet tried: After terminating cool-season brassicas and celery between April and June, their late spring sowing of partridge peas were too late this year to be productive, because the hard seed was very slow to germinate. Partridge pea could be a good cover crop for mid- to late-summer, if you scarify those hard seeds to speed germination.

Some cover crops can be alternate hosts for pathogens like cercospora, rust, or bacterial leaf spot, so be on the lookout for new problems while solving old problems. In the deep south, beans, yard-long (asparagus) beans, and cowpeas can succumb to heat, nematodes, rust, bacterial spots, and other pathogens and pests. Senna (tall) and Partridge pea can provide “chop-and-drop” organic matter as sunnhemp does. Sunn Hemp can host foliar pathogens (some possibly seed-borne), in Florida, and does not reliably form nitrogen-fixing nodules on the roots, even when inoculated. Even so, it is useful as a fast warm season green manure cover.

The flower Gaillardia (blanket flower) is a quick-to-compost, chop and drop option for late winter to late spring, It decomposes quickly, and can provide a quick green manure. Gaillardia is nematode-resistant, great for beneficials and pollinators, but is susceptible to some foliar pathogens later in the season. You can sow Gaillardia in August, or even later in fall for early spring flowering.

Due to climate change, and the more year-round activity of nematodes, pathogens, and pests in Florida, they’ve been including more nematode-resistant grasses into their rotations. We all need to be thinking more about warmer-climate options, as climate change continues to push pathogens and pests farther north, earlier each year.

Winter hoophouse growing

Hoophouse Yukina savoy at the end of November.
Photo Ethan Hirsh

Last week I wrote about Winter Preparations for Vegetable Gardens. For those with a hoophouse, here are some notes on all the work we can do to grow winter crops there! For those without a hoophouse as yet, scroll to the end for Twenty Benefits of Having a Hoophouse

First, a roundup of previous blogposts on winter hoophouse topics.

Planning winter hoophouse crops includes a description of how we do our hoophouse crop planning so we can maintain a crop rotation and still pack the beds fully with hardy crops.

Fall hoophouse bed prep and shadecloth removal includes spreading compost, broadforking, and a step-by-step guide to hoophouse fall bed prep.

Hoophouse fall bed prep Plans A-D and spider-webs includes some lovely spider photos and a short video of ballooning, as well as info about our first-planted winter crops.

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

Young greens in the hoophouse.

After the set-backs with our winter hoophouse greens transplants that I wrote about in Hoophouse fall bed prep Plans A-D and spider-webs, we worked really hard and got the whole house planted up. Most of the transplants have recovered from their transplant shock (wilting each day), during the cloudy weather we had.

The new seedlings are coming up fast and calling on us to thin them. We ended up not needing so many of the Plan D plug flat plants, but we’ve kept them for now “in case” .

Plan D: Winstrip seed flats in our hoophouse on Oct 16, a late attempt to catch up!
Photo Pam Dawling

Ultimately if we don’t need them, they’ll go in a salad mix. I wrote about Making baby salad mix last year. The past two days I have been able to harvest a mix in the hoophouse. The ingredient we are shortest of is lettuce. My first mix was spinach, Bulls Blood beet leaves, a few leaves of Tokyo Bekana, Bright Lights chard, Scarlet Frills, Ruby Streaks and Golden Frills, and a handful of lettuce leaves Red Tinged Winter is growing fastest, of all the varieties we planted this year.

Sowing hoophouse winter crops includes some discussion of the tools we like; pre-sprouting spinach seed and growing multi-leaf lettuce.

What’s growing in the hoophouse; reading; planning for winter is an October view of crops.

Frilly Mustards in our Winter Hoophouse is exactly what it sounds like. Four sowings, six varieties. All delicious.

Making baby salad mix includes a discussion of ingredients and methods, balancing nutrition, color, shape and loft.

Young green Panisse and red Revolution lettuce in our hoophouse in November.
Photo Pam Dawling

Cold-tolerant lettuce and the rest, our January 2018 assessment of the varieties we grew that winter and which survived the unusually cold spell we had. Includes sad photos of the casualties!

Also see my Mother Earth News blogpost from August 2018 Grow Great Lettuce in Winter

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Hoophouse seedlings growing outdoors under insect netting. Starting transplants outdoors helps the rotation by reducing the time the crop is growing in the hoophouse
Photo Pam Dawling

Do you value crop rotation in your hoophouse?

In the winter 2019-2020, a reader in the Pacific Northwest wrote: “This winter I have been re-thinking my crop rotation plan after having some issues (with flea beetle larvae in the soil outsmarting my diligent insect netting of my brassica salad crops). These days I see intensive market gardeners seeming to not worry so much about rotation (i.e. Neversink farm, etc), and yet I’ve always been taught that it is such an important principle to follow. I reviewed your slideshows on crop rotation and also cool crop planning in the greenhouse (which briefly addresses salad brassica rotation with other crops). With how much space I have and the high demand I have for brassicas, for salad mix (mustards) and also the more mainstay cole crops, I had settled on a 2.5 yr between brassica crop rotation (but planting two successions of mustards in the same bed within one year, in the year the bed was in mustards, with a lettuce or other crop breaking up the successions, with the idea that they were very short day and also light feeder crops). Wondering if you think this just doesn’t sound cautious enough, or if this sounds like a reasonable compromise with not having more space to work with (and wanting to satisfy the market demand for brassicas).”

I replied: “Yes, I do think crop rotation is important. I do know some farms seem to have given it up. I think what you are seeing shows one reason why rotation is important. In our hoophouse, we do as you do, allocating brassicas to a space for that winter season and perhaps doing more than one round of brassica crops. Then moving away from brassicas for the next two winters. If doing that doesn’t get rid of the flea beetle problem, and you are being thorough about netting with small-enough mesh netting (sounds like you are, but maybe check the mesh size), then my next step would be spinosad when the flea beetles appear. You can spray the inside of the netting too, and close it quickly. It’s that or a longer rotation, which it sounds like is not financially viable. You could also try farmscaping and/or importing predatory insects (not sure if there are any), Are there beneficial nematodes that attack flea beetle larvae? These are things I don’t know about, but might be worth looking into.”

Doing a spot of research today, I find that Heterorhabditis bacteriaphora, (Hb nematodes) a beneficial nematode fromArbico Organics will attack flea beetles. also known as NemaSeek, and sold separately. This is the wrong time of year for introducing nematodes in most of the US. They need warm weather to thrive.

Another suggestion from Arbico is BotaniGard Maxx & other B. bassiana sprays, which infect and kill adult flea beetles. Repeat applications as needed throughout the growing season.

Kaolin clay (Surround) is another possibility.

Also see Harvest to Table on the topic of dealing with flea beetles

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View through the hoophouse doors in December.
Photo Kathleen Slattery

Add a hoophouse to your food production

For those of you wistfully thinking about a hoophouse, let me help you a step closer to having one next year! Sales of my Year-Round Hoophouse book are doing well, which suggests to me that quite a few gardeners and growers are thinking in this direction.

Twenty Benefits of Having a Hoophouse

An extended growing season because plants are protected from cold weather.
Faster growth and higher total yields.
Beautiful unblemished crops not battered by the elements.
Fewer foliar diseases because the leaves can stay dry.
Crop survival at lower temperatures in the hoophouse than is possible outdoors.
Better crop recovery in winter due to warm sunny days following the cold nights.
Some protection from deer and other pests large and small.
Soil temperature stays above 50F (10C) in zone 6b. Warm soil = faster cold weather growth.
Higher proportion of usable crops – more food, higher sales dollars.
Diverse crop portfolio – grow crops that wouldn’t succeed outdoors in your climate.
Harvest whenever you need the crops, even during pouring rain!
Wonderful working conditions – no need for gloves and hats; take off your coat.
A food garden on a manageable scale.
A place to enjoy practicing intensive food production.
The chance to have an area completely free of weeds – new weed seed doesn’t blow in.
No need to work with heavy machinery.
Much better value for producing crops (per dollar invested) than a heated greenhouse.
Can be constructed by generally-handy people. Specialists are not needed.
NRCS grants are available for some hoophouses. Natural Resources Conservation Service, Environmental Quality Incentives Program, High Tunnel System Initiative.
Ecological energy use. The embodied energy of the plastic is less than the energy that would be used to ship similar produce from somewhere warmer (Eliot Coleman, Four Season Harvest). Another study found this was not true for smaller (9 x 12 m) hoophouses – although the economic incentive for growers is still true, there is no energy efficiency advantage to the planet. Smaller carbon footprint: shipping 1 kg lettuce has 4.3 times the CO₂ footprint of locally grown hoophouse lettuce. Plawecki, R., Pirog, R., Montri, A., & Hamm, M. (2014). Comparative carbon footprint assessment of winter lettuce production in two climatic zones for Midwestern market. Renewable Agriculture and Food Systems, 29(4), 310-318. doi:10.1017/S1742170513000161.

September sown White Russian kale (transplanted in October).
Photo Wren Vile

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Know your climate

WeatherSpark climate summary for Louisa, Virginia. Go to the website to click for more information

The WeatherSpark website provides “The Typical Weather Anywhere on Earth”. Enter your nearest town or airport and you get clearly explained info with fascinating graphics of how the weather goes over the year in your locality. Note this is not a forecast site, it’s about average weather for each place. Useful to people who’ve recently moved and want to know what to expect this winter, or to new gardeners who haven’t paid so much attention previously. Or to those who want to check their assumptions (I really thought the wind was out of the west more of the time than records say). There are charts of high and low temperature, temperature by the hour each month, cloud cover, daily chance of precipitation (both rainfall and snowfall), hours of daylight, humidity, wind speed and direction and solar energy. A big help in making wise decisions. I know that climate change is going to cause havoc with averages, and we’ll need to learn to become better weather forecasters individually, and to use soil temperature and other metrics to decide when to plant. This website explains things well.

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Winter gives a time for most of us to ponder success, failure, and possibilities for doing things differently.

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 Greens in October: Yukina Savoy, Tatsoi

Yukina Savoy is a very delicious cold tolerant cooking green. It grows in a rosette, like tatsoi, but bigger, less shiny, more blistered. It survives down to 10°F (-12°C) outdoors, so is a good outdoor crop in late fall. Ours is doing so well this year that we started eating outer leaves in early October, planning to eat more later. We eat from the outdoor crop from mid-October until mid-December. Outdoors, we transplant them 12″ (30 cm) apart.

Yukina Savoy outdoors in December, after several nights at 16-17°F (-8 to -9°C)
Photo Ethan Hirsh

We have also transplanted some in our hoophouse (sown 9/15) to feed us in December and January. A second sowing (9/24) will feed us in January and February. It is fast-growing in the fall, taking 21 days to reach baby size, 45 days to full size. The plants grow quite large, we transplant them at 10.5″ (26 cm) apart. They grow 12″ (30 cm) tall.

In the spring (which comes early indoors) Yukina Savoy has the advantage of being somewhat heat-tolerant – it doesn’t bolt until the middle of March in there. Of course, we aim to have eaten it all before they get a chance to bolt.

For commercial sales, the whole plants are cut, gathered and fastened with a tie. For home use, you have the option of simply taking the leaves you want for immediate use, and letting the heart of the plant continue to make more growth.

The photo to the left shows the open-pollinated variety we used to buy from Fedco Seeds, but sadly they no longer have that. Instead we bought a hybrid Koji from Johnnys Selected Seeds. Koji claims to be “attractive, upright, and earlier maturing than Yukina Savoy, which it replaced.” I think the “more upright” and possibly the “earlier maturing” parts are true. Attraction is in the eye of the beholder. I think Koji is less cold-hardy and less blistered than the OP type, shinier, and with greener stems.

I’ve found the OP one at Kitazawa Seeds, where it is classified as Chinese cabbage, loose head type. It’s a Brassica Rapa Pekinensis Group, for those considering saving seed.

The only photo of the Koji fully grown that we have is here on the left. This one is bolting, so it’s not a totally fair comparison.

Both types are delicious, and easy to cook.

We had been including Yukina Savoy in our hoophouse bed which has nematodes, thinking it is Brassica Juncea, which has some resistance to root knot nematodes. Back to the drawing board, on that plan!

Tatsoi is a smaller, shiny dark-green leafed plant with whiter stems. The leaves are sometimes described as “spoon-shaped” – the white stem is the spoon handle and the leaf blade is the bowl of the spoon. The plant grows as a flat rosette if it has plenty of space, but more upright if crowded as in the photo above. The flavor is milder than Yukina Savoy. In the fall, it takes 21 days for baby salads; 45 days for cooking. We don’t plant tatsoi in spring, as it would bolt before growing in our “Instant Summer” climate.

Tatsoi is also very cold-tolerant, similarly hardy to 10°F (–12°C). We no longer grow this one outdoors, because Yukina Savoy is bigger and easier. We prefer our small plants be in the hoophouse, where there are almost no weeds, and we don’t mind spending longer harvesting in winter. (More tatsoi per bucketful than Yukina Savoy = more time).

We direct sow in the hoophouse on Sept 6, one of our first fall hoophouse sowings. We sow rows 6″ apart, knowing they will get crowded. We thin into salad mixes, leaving some plants to mature at 10″ (25 cm) across for cooking greens. Tatsoi also transplants easily – I’d probably go for 6″ (15 cm) spacing if transplanting. The first sowing feeds us from 10/20 – 12/31, with thinnings for salad from Oct 8.

We make a second hoophouse sowing on November 15. This one takes 8 days to germinate. It will feed us from 2/12-3/12 (thinnings 12/27-1/21). So, altogether, we have full size tatsoi to harvest from October 25 – March 5. We usually either thin out the plants, or cut outer leaves until we see the plants are about to bolt, then cut heads.

Kitazawa Seeds have a Red Tatsoi, a Red Violet tatsoi/pak choy hybrid, with an upright habit, and several tatsoi crosses, such as Misome (a fairly recent hybrid between Komatsuna and Tatsoi); Da Cheong Chae (with qualities of both Tatsoi and Pak Choi); Choho (one of several hybrids of Komatsuna and Tatsoi); and Savoy Tatsoi (dark green, heavily savoyed leaves with pale green petioles, giving it a spinach-like appearance).

Tatsoi in the hoophouse morning mist. Photo Wren Vile

Asian Greens for August: fall senposai, winter Yukina Savoy

Brassica seedlings under insect netting.
Photo by Bridget Aleshire

In late June and early July, we sow nursery beds of brassicas for transplanting outdoors. In the photo above, the plants at this end of the bed are cabbages, but in the same bed there are also Asian greens for fall and early winter harvests. We cover the beds with ProtekNet, which I already told you about in my Asian Greens for July post.

We sow the seeds about 3/inch, sowing about a foot of nursery bed row for each 12-15 feet of final crop row we want. And we sow twice, a week apart, to cover contingencies like poor germination or needing to replace casualties a week later. We transplant them three weeks after sowing, at the end of July or in early August.

Brassica beds covered with ProtekNet insect netting.
Photo Wren Vile

We cover the beds of transplants with more ProtekNet, for the first month. This is part of our strategy for dealing with harlequin bugs. We try to have August be “No Visible Brassicas Month” – we remove the old spring brassicas, or till them under, and we keep all new brassicas under cover. We hope that a month or more with no food (except cleomes) will stymie the harlequin bugs lifecycle.

We grow Yukina Savoy for harvests from mid-October to mid-November (more on that in November), and senposai for harvests from August 20 to November. Any day now we can start harvesting senposai! Both these crops get followed by a supply from the hoophouse (more on that in late winter).

I know it’s only three months since I last wrote about senposai, and here it is again! If you ran out of seeds in the spring, or this is a new vegetable for you, hurry and order from Fedco Seeds in Maine. Their order deadline is October 31 for this year. Also available from Kitazawa Seeds or Evergreen Seeds

For fall harvests, sensposai is ready a mere 40 days from sowing, or 10 days longer if you disturbed it and transplanted, as we do. Depending on your winter climate zone, you may have time to sow for growing in a hoophouse (zone 6 or warmer), or outdoors (zone 8?). If you had a cabbage disaster, try fast-growing senposai.

An outdoor bed of young Senposai.
Photo by Wren Vile

Senposai is an F1 hybrid, so don’t try saving your own seed, if you want reliable production. It was developed in Japan, and is a cross between Japanese Mustard Spinach (Komatsuna Brassica rapa – more on this next month) and regular cabbage. Senposai has big round medium-green leaves, and an open growth habit. It needs a generous 12″–18″ spacing, unless for some reason you want to limit the generous size of the leaves. The flavor is sweet and the texture is tender. Photo by Fedco Seeds. As a Fedco customer reports:

“Customers buy it once because it looks absolutely stunning, then they buy it again because it is extremely delicious. Absurdly productive and easy to grow”

Senposai leaves are cold-tolerant down to 12F (-11C), and the core of the plant may survive 10F (-12C). Young plants can be used for salads.

Asian Greens for July: Maruba Santoh, plus sowings for fall

Young Maruba Santoh plants
Photo by Ethan Hirsh

In June I told you about Tokyo Bekana, a light green tender-leaved, white-stemmed green which can be cooked, or used as a substitute for lettuce in hot weather. Because summer in Virginia is a hard time for leafy greens, July’s Asian green is very similar – Maruba Santoh. Maruba Santoh has smoother, wavy, less ruffled leaves than Tokyo Bekana.

To show you I’m not being a slouch, I’ll include some pointers on sowing Asian greens for fall, because now is the time – in our climate at least. Here’s what one of my favorite seed suppliers, Fedco Seeds has to say:

Maruba Santoh (35 days) Brassica rapa (pekinensis group) Open pollinated. With Maruba you get four vegetables in one. The loose round vibrant chartreuse leaves provide a mild piquant mustardy flavor while the flat white stems impart a juicy crisp pac choy taste. High-end chefs like to use the blossoms. Market grower Scott Howell finds the flavor more subtle and complex than that of other greens and cuts Maruba small for his mesclun. Fairly bolt tolerant, so plant after the early spring flea beetle invasion subsides.

Harlequin bugs.
Photo University of Maryland Extension Service

Fedco is in Maine and we’re in Virginia, so things are a little different. The information on their website about pests and diseases is good. Our worst brassica pests are harlequin bugs.

We grow our summer brassica seedlings and transplanted Asian greens under ProtekNet on hoops. On the Dubois link, study the Dimensions and Specifications tab, then download the brochure from that tab. Study the Descriptions tab – it tells you which insects are excluded by each size mesh. Be sure that you choose the right size mesh for the bugs you want to exclude. Flea beetles and thrips are small – you need a small mesh. Johnny’s is now marketing the close-mesh ProtekNet as “Biothrips” insect netting, and they also have a comparison chart of rowcover and insect netting on their site.

Adolescent Maruba Santoh plants bunched for market.
Photo Kitazawa Seeds

Kitazawa Seeds also sells Maruba Santoh seed, under the Chinese Cabbage heading. Like most brassicas, Maruba Santoh does best in cool weather, although it is somewhat heat tolerant (or “warm tolerant” as we call it in Virginia.) It tolerates heat better than Napa Chinese cabbage does. To avoid bolting, keep the plants above 50F (10C) at all times, but particularly avoid prolonged spells below this “bolting trigger” temperature.

Maruba Santoh will germinate at temperatures between 50-85F. Seedlings emerge in just 3 days in summer. For summer use, direct sow, thin the rows for baby salad mix, then let the “heads” (it doesn’t actually head up) develop to full size (6-10″ tall) after about 35-40 days. Or transplant two week old starts. We tend to grow our plants quite big (12″ tall) and harvest by the leaf, several times over. Maruba Santoh makes a fine substitute for lettuce, and a tasty quick-cooking green.

To calculate sowing dates, work back 40 days from when you want to harvest, and sow more every week or two until you run into the fall slowdown temperatures, or you go back to eating lettuce in salads and cooking chard and kale. If you still have Maruba Santoh growing in the fall, know that it will be frost tolerant to 25°F (-4°C). No hurry.

Newly transplanted Maruba Santoh.
Photo Ethan Hirsh

Maruba Santoh can also be grown at other times of year: spring and fall outdoors, winter in the hoophouse. The seedlings have large cotyledons and make good microgreens too.

Kitazawa’s Culinary Tips include: Use in salad, sukiyaki, ohitashi, yosenabe, stir-fry, soup and pickling. Kim chi here we come! (If we had surplus.)

Next month I will talk more about Asian greens outdoors in fall. Now is the time to sow for fall harvests. We start in late June, and sow more in early July. We always make two sowings a week apart, for insurance. We are aiming for greens to feed us in early fall, before the kale is ready, and into the winter, harvesting by the leaf. But Asian greens can be sown all the way up to two months before your first fall frost date. For us, that means August 14-20. If you want to make sowings now, consider senposai, komatsuna, pak choy, tat soi, Yukina Savoy, and Chinese cabbage.

An insectary circle with borage and sunflower in a chard bed.
Photo Bridget Aleshire

I have two posts on the Mother Earth News Organic Gardening Blog that I haven’t told you about yet. So if it’s too hot out, or it’s raining (don’t make me envious) seek shade and read more. The newer post is Insectaries: Grow Flowers to Attract Beneficial Insects, and the previous one is Planting Leeks.

Hoophouse winter greens, transplanting spinach, crocus flowering

Russian kale, yukina Savoy and lettuce from our winter hoophouse .
Photo Wren Vile

Our hoophouse is bursting with winter greens. We just decided to hold back on harvesting our outdoor Vates kale and focus on the greens which are starting to bolt in the hoophouse. That includes the last turnips (Hakurei, Red Round and White Egg), Senposai, tatsoi, Yukina Savoy, mizuna, Ruby Streaks, Scarlet Frill and Golden Frills mustards. Big but happily not yet bolting are the spinach, Rainbow chard and Russian kales. A row of snap peas has emerged. Time to stake and string-weave them!

The lettuce situation is changing as we are eating up more of the overwintered leaf lettuce in the hoophouse. The lettuces in the greenhouse have all gone, to make way for the flats of seedlings. Plus, we needed the compost they were growing in, to fill the flats. More about lettuce in February next week.

We have also cleared the overwintered spinach in one of our coldframes, so we can deal with the voles and get them to relocate before we put flats of vulnerable seedlings out there. The voles eat the spinach plants from below, starting with the roots. We had one terrible spring when they moved on to eat the baby seedlings when we put those out there. After trial and error a couple of years ago, we now clear all the spinach from one frame, then line the cold frame with landscape fabric (going up the walls a way too), wait two weeks, then put the seedlings out on top of the landscape fabric. The voles by then have decided nothing tasty is going to appear there, so they move on.

Spinach over-wintered in our cold frame
Photo Wren Vile

Outdoors, we have just started transplanting new spinach. We have four beds to plant, a total of 3600 plants, so we have to keep moving on that! We are trialing several varieties again, as we did in the fall. We have the last Tyee, alongside Reflect and Avon this spring. Inevitably things are not going perfectly according to plan. Yesterday I forgot to follow the plan, and we started with Avon and Tyee at opposite ends of a bed we had planned to grow Reflect in! Anyway, we are labeling everything and hoping to learn which have best bolt resistance. Watch this space.

We have grown our spinach transplants (as well as kale and collards) in the soil in our hoophouse, sowing them in late January. I wrote about bare root transplants in early January this year. You can find more links and info in that post. Growing bare root transplants saves a lot of work and a lot of greenhouse space.

For those relatively new to this blog but living in a similar climate zone, I want to point you to The Complete Twin Oaks Garden Task List Month-by-Month. It includes a link for each month’s task list. I notice from the site stats that some of you are finding your way there, but now there are so many years’ worth of posts it’s perhaps harder to find. Happy browsing!

Following on from last week’s mention of harbinger weeds of spring: chickweed, hen-bit and dead-nettle, I can now report that I’ve seen a flowering crocus (2/17), another marker on our phenology list. The average date for first crocuses here is February 8, so they are later than usual. I did notice however, that the foot traffic over the patch of grass has been heavier than usual.

Anne Morrow Donley sent me a link to WunderBlog®, the blog from Wunderground, my favorite weather forecast station, to an article by Bob Henson: This is February? 80°F in Denver, 99° in Oklahoma, 66° in Iceland, 116° in Australia. It includes a map of the Daily Spring Index Leaf Anomaly, Figure 1.

Image credit: USA National Phenology Network via @TheresaCrimmins.

Figure 1. An index of the seasonal progress of leafy plants shows conditions 20 days or more ahead of schedule over large parts of the South and Southwest as of Sunday, February 12. Image credit: USA National Phenology Network via @TheresaCrimmins.

The post has lots of other interesting weather info too. Thanks Anne!

I remembered another of the items lost in the hacked post a few weeks ago: My Mother Earth News Organic Gardening Blogpost on Heat Tolerant Eggplant Varieties made it into their 30 Most Viewed blogposts for 2016. I’ll be writing up more about those varieties, linking the 2016 results to the weather each week (especially the temperatures) and adding what I learn in 2017.

Mid-winter hoophouse harvests

December 29 hoophouse crops Photo Kathleen Slattery — December 29 hoophouse crops
Photo Kathleen Slattery

Here we are in the shortest days. What are we harvesting from our hoophouse (high tunnel)? Many different crops, mostly leafy greens, but with the addition of radishes, turnips and scallions. I’ll start with those.

White Icicle radish Photo Southern Exposure Seed Exchange — White Icicle radish
Photo **Southern Exposure Seed Exchange**

We’re harvesting our third sowing of radishes, sown on 10/30. We like the vari-colored Easter Egg radishes and the long White Icicle for this time of year. Cherry Belle also works in this sowing, but not later. Like Sparkler, it gets too fibrous in winter.

Our favorite scallions are Evergreen Hardy White, which are extremely cold tolerant. They are also slow to grow. We are starting to harvest the ones we sowed 9/6. The second sowing (which followed the first radishes on 11/18) are just spindly little blades so far.

Hakurei turnips Photo Small Farm Central — Hakurei turnips
Photo **Small Farm Central**

The turnips (and their greens) which we are starting to harvest at tangerine-size, are Hakurei and Red Round, from a 10/14 sowing. We made a second sowing of turnips on 10/26, but we over-watered them and got patchy germination. We filled the gap with a late sowing of brassica salad mix. This is a mixture of random leftover brassica seeds (varieties we didn’t like, seed that is getting a bit old) which we sow and then cut with scissors about an inch above the soil once they get to about 4″ tall.

Baby lettuce mix in the hoophouse. Photo Twin Oaks COmmunity — Baby lettuce mix in the hoophouse.
Photo **Twin Oaks Community**

Just like baby lettuce mix. We are on our second cut of our 10/24 lettuce mix. We buy the mix already made, although if we get close to running out of seed, we have been known to mix in some seed of basic varieties like the Salad Bowls, that do well in the winter high tunnel. We also have lots of big lettuce plants. We take leaves off those for our salad mixes when we don’t have baby lettuce mix at the right stage for cutting.

Ruby Streaks beside green mizuna. Credit Ethan Hirsh — Ruby Streaks beside green mizuna.
Credit Ethan Hirsh

Into the salad mix we add chopped mizuna and its spicier cousins Golden Frills, Ruby Streaks and Scarlet Frills. These add loft, visual interest and flavor. For color we also add chopped Bulls Blood beet leaves and chopped small leaves of Brite Lites chard. As well as mixing the colors and shapes, I try to have at least one representative of each of three crop families: spinach, chard and beets; lettuce; brassicas such as mizuna, baby kale leaves, small leaves of Tokyo bekana, Yukina savoy, tatsoi.

Tatsoi in the hoophouse Photo Wren Vile — Tatsoi in the hoophouse
Photo Wren Vile

For cooking greens we are harvesting leaves of Russian kale (transplanted 10/22), our first chard (transplanted 10/16), spinach (sown 9/6 and 10/24), senposai (transplanted 10/24), Tokyo bekana (transplanted 10/9) and Yukina savoy (transplanted 10/24). it takes 10 gallons of greens to provide 100 people with a healthy serving each. We aim to provide the cooks each day with a choice of two or three different cooking greens.

We are also harvesting some greens as whole heads now. We are clearing our first planting of tatsoi (sown 9/7), which has been getting ready to bolt for a couple of weeks now. Likewise the Tokyo bekana, which starts to bolt at the end of December.

We are also cutting big heads of Chinese cabbage and Pak Choy. As we harvest these, we fill the gaps at the end of the day with replacement plants. My current favorite is senposai, as it is very quick to grow and can be eaten at any stage. (And of course, it’s very tasty, otherwise I wouldn’t even mention it!) We reckon 12/31 is the last worthwhile date for us to do this gap filling with Asian greens. After that we use spinach or lettuce transplants up till 1/25, then only spinach (up till the end of February). We’ve found that planting after those dates doesn’t produce harvest, just wasted time!

The Yukina savoy doesn’t really start bolting until the last week of January normally, but with the freakish warm weather we’ve had this December, we might get early bolting. I don’t know if this crop bolts mostly in response to day length or to temperature. I guess we’ll find out.

We’ve ordered our seeds, we’re planning our next hoophouse crops and our schedule for sowing seedlings in the greenhouse. And this is the slow season!

Bulls Blood beets add intense color to salad mixes. Photo Wren Vile — Bulls Blood beets add intense color to salad mixes.
Photo Bridget Aleshire

Heirloom tomatoes, string-weaving, seed germination temperatures

The October issue of Growing for Market is out, including my article about heirloom tomatoes. It’s an assessment of tomato varieties we have grown, mostly in our hoophouse, and how they’ve done in central Virginia. When we decide to try a new variety, we first grow just two plants, in our hoophouse with all the other weird and wonderful types we like, and a bed of early-maturing varieties like Stupice and Glacier. We also grow non-heirlooms, including hybrids like Sun Gold. We track whether we like the flavor, how productive they are and how disease-resistant they are.

Some of the winners for us are Amy’s Sugar Gem, Black Cherry, Five Star

Striped German tomato in all its beauty. Photo Southern Exposure Seed Exchange — Striped German tomato in all its beauty.
Photo **Southern Exposure Seed Exchange**

Grape F1, Garden Peach, Jubilee, Mountain Magic F1, Reisentraube, and for simple delicious reds, Tropic. We love Cherokee Purple and Striped German, but they *appear* not to be very productive. I suspect browsers got them all!

This GfM also includes practical help with financial reports from farmer Chris Blanchard, a consideration of copper-based fungicides and their bad effect on soil health, from Meredith Melendez,an Agricultural and Resource Management Agent for Rutgers Cooperative Extension. Organic farmers need to take more mindful care when using copper compounds, even when facing Late Blight. Alexandra Amonette writes from Washington state about dealing with the extreme heat this summer, and Gretel Adams encourages flower farmers to hang in there producing hardy cuts for the last part of the year.

Detail of string-weaving tomatoes: locking the twine by crossing the second wrap over the first. Photo Kathryn Simmons — Detail of string-weaving tomatoes: locking the twine by crossing the second wrap over the first.
Photo Kathryn Simmons

Mother Earth News Organic Gardening blog has published my post on string-weaving tomatoes.

If you are considering a different support system for your long rows of tomatoes next year, give string weaving a go!

I heard my book Sustainable Market Farming got a great review in Acres USA although I haven’t seen a copy yet.

We’re in the transitional period in our hoophouse, planting the winter crops. Today is Yukina Savoy transplanting and tatsoi thinning day. As an aid for future winter hoophouse planning I’ve been working on a chart of soil temperatures for best germination of vegetables, and how many days it takes for germination of each vegetable at different temperatures. This chart is a work in progress, so if you have any gems of information to contribute, do leave a comment. For instance, if you firm up any of the uncertainties, or if your experience contradicts what’s written here, I’d love to know! Click to open the pdf.

Winter Hphs Crops days to germ

Yukina Savoy in November in our hoophouse. Photo Ethan Hirsh — Yukina Savoy in November in our hoophouse.
Photo Ethan Hirsh

And a blog I’ve just signed-up for is from the same Chris Blanchard who writes for Growing for Market. It’s the Purple Pitchfork or the Flying Rutabaga (the weekly newsletter). Packed with info on farming, based on real experience, from someone who is paying close attention.

Workshops on Crop Rotations, Hoophouses in spring, summer, fall and winter.

I had a good time at the Heritage Harvest Festival this past weekend. My Friday workshop on Crop Rotations for Vegetables and Cover Crops in the Woodland Pavilion had about 56 participants. If you missed it or want to see it again it’s here. Most of my slide shows are on SlideShare.net. Search for Pam Dawling and click on the one you want to see.

Crop rotations for vegetables and cover crops 2014, Pam Dawling from Pam Dawling

Brite Lites chard in our hoophouse. Photo credit Pam Dawling — Brite Lites chard in our winter hoophouse.
Photo Pam Dawling

On Saturday I did my presentation on Asian Greens. And this morning I sowed Blues Chinese cabbage, Yukina savoy, Tokyo Bekana, and pak choy, as well as Brite Lites Chard and ten kinds of lettuce, to transplant into our hoophouse for winter greens.

Last winter we tried the Osborne Multileaf lettuces compared to Salanova types, and were well pleased with the Osborne ones. And so we are growing more of those this winter, along with Tango, Panisse, Oscarde, Merlot and Red Tinged Winter. Next week I’ll sow another ten lettuces (some of the same and some others), along with Russian kales and senposai, more Yukina Savoy and the first round of mizuna and fancy frilled mustards, such as Ruby Streaks.

Pam Dawling. Photo Denny Ray McElya — Pam Dawling.
Photo Denny Ray McElya

Next weekend (September 18-20) I will be speaking at the Mother Earth News Fair in Seven Springs, Pennsylvania. I”l be one of the Keynote Speakers, talking about Fall and Winter Hoophouses on Friday 4 – 5 pm on the Mother Earth News Stage. Then I will sign books in the MEN Bookstore immediatley following the workshop.

On Saturday 10 – 11 am on the GRIT Stage I will speak about Spring and Summer Hoophouses. That pair of workshops should give plenty of ideas for the whole year.

I’m also doing off-stage demos of tomato string-weaving (using a table-top model) twice a day at the New Society Publishers booth 104.

Because printing 600 handouts is out of the question (too many trees would have to die, and so on), I have made pdfs of my handouts to post here. Click on the links.

Hoophouse winter greens. Photo Kathleen Slattery — Hoophouse winter greens.
Photo Kathleen Slattery

Fall and Winter Hoophouses Handout

Cucumbers and squash in our hoophouse. Photo Nina Gentle — Cucumbers and squash in our early summer hoophouse.
Photo Nina Gentle

Spring and Summer Hoophouses Handout