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Home , Brassica rapa, Choy sum, KASUMI, Komatsuna, Mizuna, Napa cabbage

Optimizing your Asian Greens Production ©Pam Dawling 2019 Twin Oaks Community, Central Virginia Author of Sustainable Market Farming and The Year Round Hoophouse SustainableMarketFarming.com facebook.com/SustainableMarketFarming

I live and farm at Twin Oaks Community, in central Virginia. We are located on Monacan land. We’re in zone 7, with an average last frost April 30 and average first frost October 14. Our goal is to feed our intentional community of 100 people with a wide variety of organic produce year round year round. www.twinoaks.org

Outline 1. Meet the Asian Greens 2. Crops I recommend for easy success 3. Crops to try later 4. Crop requirements 5. Growing in spring 6. Growing in summer 7. Growing outdoors in fall 8. Crop protection: rowcover, netting, shadecloth 9. Growing in the winter hoophouse a) Packing more in Pak Choy. Credit Ethan Hirsh b) Harvesting c) Minimizing nitrate accumulation in winter 10. Pests and diseases 11. Seed saving

1. Meet the Asian Greens • Huge range of attractive varieties • Quick-growing, bring fast returns • Grow when you normally grow or kale • Short spring season, bolt when it gets hot • Long fall season, no bolting. Success depends on getting them germinated and planted in June and July Blues Napa • Grow all winter in hoophouses in shown here central Virginia Credit Ethan Hirsh Healthful Diversity  Flavors vary from mild to peppery - read catalog descriptions before growing lots  Colors cover the spectrum: chartreuse, bright green, dark green and purple  Nutritious as well as tasty  High in carotenoids, A and C, , iron, magnesium and fiber  Help prevent high blood pressure, heart disease, stroke  They contain antioxidants which fight against cancer and protect eyes from macular Photo Credit Ethan Hirsh degeneration

Advantages of Asian Greens  A quick way to fill out your market booth or CSA bags  A catch crop for spaces where other crops have failed or otherwise finished early. Keep a flat of seedlings ready, pop plugs into any empty spaces  Better able to germinate in hot weather than lettuce  Faster growing than lettuce  Faster-growing types are ready for transplanting 2 Our hoophouse in November weeks after sowing (or you Photo Ethan Hirsh can direct sow) Asian Greens – Many Types

1 2 1. Senposai - cold-hardy 2. Pak Choy 3. - cold-hardy 4. Chrysanthemum greens 5. Yokatta-na 6. - cold-hardy 7. Ruby Streaks, Scarlet Frills 7 5 3 & other mustards 8. Mustard-based salad mixes 9. 10. Yukina Savoy- cold-hardy 11. Napa Chinese Cabbage 12. Tokyo Bekana 6 13. Maruba Santoh 4 14. Mizspoona 15. Toraziroh 16. Thick-stemmed mustard 17. Hon Tsai Tai

Who’s Who – 3 botanical groups 1) The family, rapa, of 2) The cabbage family, B. Asian origin oleracea, of European origin a) var. pekinensis (napa Kai-lan, Chinese kale, Toraziroh cabbage, michihli, celery cabbage) b) B. rapa var. chinensis () c) B. rapa var. japonica (mizuna) d) B. rapa var. narinosa (tatsoi, Yokatta-

na) e) B. rapa var. perviridis (komatsuna) Different sources use different names 3) The Chinese Mustard If you plan to grow of more than family, B. juncea one Asian green, carefully choose ones Ruby Streaks (shown here, that won’t cross. Be aware of the Photo Johnnys Seeds), possibility of brassica crops being Golden Frills, Red Rain, Wild Garden Pungent Mix wrongly classified 2. Crops I recommend 1a. Brassica rapa var. pekinensis. • A type of wong bok • Very tender, light green leaves • Excellent for stir-fries, • Hardy to about 25°F (–4°C) • We like Blues (52 days from seed to harvest) best • Kasumi has the best bolt tolerance and is larger: 5 lb (2.3 kg) compared to 4 lb (1.8 kg) • Orange Queen is a colorful but slower-growing variety (80 days) • Stores better than michihli Photo Kashruth Council of Canada types

1a. Brassica rapa var. pekinensis Michihli (Cylindrical Wong Bok) Chinese cabbage • Produces 16" (40-cm) tall heads 6" (15 cm) across. • More productive than Napa cabbage in the same space • Very tender, light green leaves • Great for stir-fries and pickling. • More stress tolerant and resistant to bolting and black than Napa cabbage • Cannot be stored as long. • We like Jade Pagoda (72 days) and the O-P Michihli (72 days) Photo Southern Exposure Seed Exchange 1a Brassica rapa var. pekinensis Celery cabbage (pe tsai) • A fast-growing, looseleaf, non- Photo credit Johnnys Seeds heading with light green leaves and white petioles. • Mild flavor, tender texture: can be substituted for lettuce • Can be ready for harvest 3–4 weeks after sowing. • More heat tolerant than Napa. Cold tolerant to 25°F (-4°C) • Fairly bolt resistant • Maruba Santoh and Tokyo bekana are very similar 1a or b Brassica rapa var. pekinensis or var. chinensis Tokyo Bekana • Fast-growing tender chartreuse frilly, leafy . • Mild flavor • 21 days to baby crop, 45 days to full maturity • The leaves and wide white stems of the mature plant provide crunch for salads • Mature can be chopped and lightly cooked Young Tokyo Bekana seedlings in our November hoophouse. Photo Ethan Hirsh 1a Brassica rapa var. pekinensis Maruba Santoh

• A fast-growing chartreuse (yellow-green) tender-leafed plant • Can be harvested as baby leaves • Or the leaves and wide white stems of the mature plant provide crunch for salads • Or whole plants can be chopped and lightly cooked • Only 21 days to baby leaf, 35 days to maturity, and is fairly Photo Ethan Hirsh bolt resistant 1b. Brassica rapa var. chinensis Pak Choy, Bok Choi • Previously known as Chinese mustard cabbage • Sturdy white leaf stems, big green leaves. Usually harvested as a head 12"– 15" (30–38 cm) tall • 45–55 days to maturity • All are hardy down to 32°F (0°C), most varieties Photo Johnnys Seeds to 25°F (-4°C)

Pak Choy • Can be picked as Red Choi Photo Kitazawa Seeds. http://www.kitazawaseed.com/seed_443 individual leaves, for -77.html bunches of mixed braising greens or stir- fry combinations • We grow Prize Choy or Joy Choi • There is also red choi (a 45-day, red-veined baby leaf or maroon-leaved full-size version)

1c. Brassica rapa var. japonica Mizuna (kyona) • Very easy to grow, tolerates cold wet soil • Use for baby salads after only 21 days • Or thin to 8"–12" (20– 30 cm) apart, to grow to maturity in 40 days • Fairly heat tolerant (well, warm tolerant) • Cold tolerant to 25°F (-4°C) Photo Ethan Hirsh Mizuna Photo Ethan Hirsh • Mild flavor • Ferny leaves - add color and loft in salad mixes • Regrows vigorously after cutting • Available in green or purple (but Ruby Streaks mustard is much better than Purple Mizuna!)

 Mizuna  Ruby Streaks  Strap-leaved mibuna  Purple mizuna 3. Red Splendor, Ruby Streaks, Golden Frills Johnny’s Red Splendor Ruby Streaks Credit Southern Exposure Seed Exchange

Golden Frills

1d. Brassica rapa var. narinosa Tatsoi (tah tsoi) • A small plant, a flat rosette of shiny, dark green spoon- shaped leaves and green- white stems • 21 days for baby salads; 45 days for cooking • Mild flavor, an attractive appearance • Very cold tolerant, hardy to 10°F (–12°C) • Easy to grow - here’s how - Photo Ethan Hirsh Tat soi • Direct sow and then thin into salad mixes, leaving some to mature at 10" (25 cm) across for cooking greens. • Can transplant at 6" (15 cm) • Kitazawa Seeds have a Red Violet tatsoi/pak choy hybrid, with an upright habit

Photo Wren Vile Photo Kitazawa Seeds http://www.kitazawaseed.com/seed_369-77.html 1e. Brassica rapa var. perviridis or Brassica rapa v. komatsuna Komatsuna Photo Fothergill Seeds • Also known as mustard spinach Photo credit Fothergill (so is Pak Choy!), Summer Fest Seeds • Green or red (purple) • Baby salad size in 21 days, full size in 35 days • A large plant 18" (45 cm) tall • Pick and bunch individual leaves • Or harvest the whole plant • The flavor is mildly peppery • Cold-tolerant to 15°F (-9.5°C), perhaps 10°F (-12°C)

1. Brassica rapa Yukina Savoy • Like a bigger tatsoi, 12" (30 cm) tall • Blistered dark green leaves and green stems • Delicious flavor • Tolerant to heat and cold – down to 10°F (-12°C) outdoors • Transplant at 12" (30 cm) • 21 days to reach baby size, 45 days to full size Photo Ethan Hirsh

Yukina Savoy Outdoors in December, after several nights at 16-17°F (-8 to -9°C) Koji and Red Cloud In our experience, OP Yukina Savoy is more cold-hardy and bolt-resistant than hybrid Koji. Koji is an F1 hybrid tatsoi for baby leaf or bunching. Johnny’s Seeds, who sell it to replace Yukina Savoy, report that it is more upright and faster- maturing (21 days to baby leaf, 43 days to full size). Space 12” (30 cm) apart. Red Cloud is Johnny’s smaller, burgundy hybrid tatsoi

Red Cloud photo Johnny’s Seeds Hybrid of 1e. Brassica rapa var perviridis & Senposai - Our Star of Asian Greens • A cross between komatsuna and regular cabbage. • A big non-heading plant producing large, round, mid-green leaves which are harvested leaf by leaf. • Cooks quickly (much quicker than collards) • Delicious sweet cabbagey flavor, tender texture. Photo Kathryn Simmons

Senposai • Transplant at 12"–18" (30–45 cm) spacing; it really will use all this space • Grows fast. Only 40 days to mature. • Very productive, usually harvested leaf-by-leaf • Heat and cold tolerant (down to 12°F (-11°C) A bed of senposai 15” apart

Photo Kathryn Simmons in the row, 3 rows in 48”

Senposai in November the young hoophouse crop is almost ready to take over from the well-used outdoor crop.

Senposai. Photo Ethan Hirsh Asian-type Brassica Salad Mixes Wild Garden Pungent Mix, Pink Petiole Mix, Brassica rapa Brassica juncea, (Wild Garden (Wild Garden Seeds, Fedco) Seeds, Fedco) Fast-growing, cold tolerant, adds A cross of pungent Indian mustards a touch of color to the brassica for those who like Big Flavor. 40 portion of winter salad mixes. A days to harvest. varied mix of colors and shapes. Photos Wild Garden Seeds Ready in 40 days.

Winter Radish, Including Daikon • We sow winter radish outdoors on August 4. ( Rose and a daikon. ) • We harvest in October or November before temperatures drop to 20°F (-7°C) • Stores well in perforated plastic bags under refrigeration • Popular for making Kim Chee, as well as for salads and stir-fries.

Frosty daikon. Photo Bridget Aleshire 3. Crops to try later Small and/or short-lived greens . Hon Tsai Tai, Brassica rapa, (like a purple raab). Also known as . Mostly stem with small clusters of buds. In climates cooler than Zone 7 this might be productive in the fall. For spring it could be a challenge most places. It matures in only 35–40 days. Hardy to 23°F (–5°C). . Broccoli Raab, Brassica rapa ruvo. We had the same trouble with this as with Hon Tsai Tai Photo Johnnys Seeds . Mei Qing Choi, A miniature 6" (15 cm) pak choy. We don’t do well with miniature crops. These might suit your market, but we do better with larger . It matures in less than 45 days, a definite plus . Green/Bitamin-Na/Yokatta-Na, Brassica rapa var. Narinosa. A slender, white-stemmed plant, about 12" (30 cm) tall. It can be planted 4" (10 cm) apart, or direct sown and thinned. Tolerates heat and cold. Quick- growing with good flavor, not pungent: 21 days for salad mix, 45 to full size Big Sturdy Greens

. Tyfon Holland Greens - a strong

plant, a hybrid of komatsuna with a heading brassica. Could

be good in a survival situation, or Mizspoona photo Wild Garden Seeds to grow for goats, or to make https://www.wildgardenseed.com

green juices. Hardy down to 20°F (-7°C). . Mizspoona, Brassica rapa, a large sturdy plant, 40 days to maturity. A sweet flavor with a good balance of mild zinginess. A gene pool (variable plants). Mizuna crossed with Tatsoi.

More Big Greens . Chinese Thick-Stem Mustard (SESE, Fedco, Even' Star Organic Farm, Maryland). Multiple cuttings of balanced-flavor salad mix crop to fill the CSA bags. Extremely cold tolerant, down to 6°F (-14°C). . Tenderleaf – a big, sturdy, OP plant. Quick-cooking, mild-flavored, despite appearances. Selected from a cross of Tendergreen and tatsoi. Very disease-resistant and cold tolerant down to 20°F (-7°C). Can be sown later in the fall than other greens - could be the solution if your original plan didn’t work. Can be a useful salad mix crop at the baby stage.

Chinese Thick-Stem Mustard. Photo Heirloom Seed Supply Chrysanthemum Greens (Shungiku) Photos • Chrysanthemum coronarium. https://plantfreak.wordpress.com These have a very distinctive aromatic flavor, which you may or may not love. • The flowers are very pretty, if you give up harvesting the leaves. • 21 days for baby greens, 45 days to full size. 4.Crop Requirements for Asian Greens Similar care requirements to other , Closely monitor pests, which can build up large populations during the summer. Very fertile soils grow the best Asian greens, Turn in leguminous cover crops or compost to provide adequate nutrition.  Shallow rooted - Pay extra attention to providing enough water during hot weather to prevent bitter flavors and excess pungency,

Irrigation 1” (2.5 cm) of water per week 2” (5 cm) during very hot weather Drip irrigation saves water, reduces disease and weed pressure Overhead irrigation can be cheaper and easier to set up for crops that will be harvested before much time has passed. Overhead sprinklers can wash Ruby Streaks mustard with drip irrigation. off - could be all the Photo Ethan Hirsh control you need Sow or Transplant?

We almost always transplant brassicas because we use our growing spaces very intensively. We grow a lot of brassicas and our crop rotation is always pushed and stretched by the amount of brassicas we’d like to plant – transplanting allows the soil extra weeks without brassicas. Transplanting gives the previous crop extra time. If we have 4 weeks between the end of one crop and transplants going in, we sow buckwheat to add organic matter and smother weeds. 5. Growing in Spring In spring we sow in flats in a greenhouse, to get an early start. We transplant spring Asian greens at 4–5 weeks of age, about a month before our last frost date, and use rowcover for a few weeks. Direct sowing has the Photo Kathryn Simmons advantage that thinnings can be used for salads. 6. Summer Tokyo Bekana Provided you can keep bugs off, and supply enough water, Tokyo bekana and maruba santoh will germinate and grow quickly to provide mild-flavored salad leaves during late-summer lettuce shortages. Full size in just 5 weeks from sowing in warm weather.

7. In Summer (for Fall Outdoor Crops) We prefer outdoor seedbeds for summer sowings, because it is easier to keep the plants watered. We make an outdoor nursery bed, sow at about three or four seeds per inch (5–10 mm apart), and cover with rowcover or ProtekNet. The seedlings emerge in as Bare-root transplants. Photo credit Ethan Hirsh little as three days in summer temperatures.

For Fall Outdoor Crops

We start sowing our fall Asian greens for outdoor planting around June 26 and repeat a week later for insurance (July 3), the same dates we sow fall broccoli and cabbage. Last date for sowing these crops is about 2 months before the first fall frost date. In our case that means August 14–20.  Photo credit Kathryn Simmons

Transplanting for Fall Crops In summer, the faster growing Napa cabbage, Tokyo Bekana and Maruba Santoh are ready to plant out at 2 weeks old. Most others transplant best at 3–4 weeks (less time than in spring). We transplant outdoors July 10 - 31 for early fall crops. Later is possible. To minimize transplant shock, water well an hour before planting, get them in the ground quickly and water again. Shadecloth or rowcover will help keep the breezes (if any!) and strong sun off the plants.

Tokyo bekana transplant. Cold-Hardiness  32F (0C): Some Pak Choy  25F (-4C): Chinese Napa cabbage, Maruba Santoh, Mizuna, most Pak Choy, Red Giant Mustard, Tokyo Bekana,  20F (-7C): Tendergreen, Tenderleaf, Tyfon Holland Greens  15F (-9.5C): perhaps Komatsuna  12F (-11C): Senposai (may be OK down to 10F (-12C)  10F (-12C): Green-in-Snow mustard, probably Komatsuna; Tatsoi, Yukina Savoy, winter radishes  6F (-14C): Thick-stemmed Mustard Spring Bolt Resistance In spring the order of bolting of Asian greens is: tatsoi, Maruba Santoh, Tokyo bekana, Koji, Napa cabbage, pak choy, Yukina Savoy, Komatsuna, mizuna, leaf radish. Hot Weather Season Extension Insect Netting Shadecloth ProtekNet is available from Purple Mountain Organics, duboisag.com and other suppliers. Choose size

Asian greens have no problem germinating in temperatures up to 95F (35C) Cold Weather Crop Protection Three basic levels of protection: 1. Rowcover 2. Quick Hoops and Caterpillar Tunnels 3. Hoophouses (High Tunnels) Rowcover • keep frost-tender crops alive and productive beyond the first few fall frosts • keep hardy crops alive in winter • protect young plants in early spring. Photo Kathryn Simmons Rowcover in the Hoophouse On very cold winter nights (below 8F (-13C) outdoors) and frosty nights after transplanting tender crops, we use thick rowcover – Dupont Xavan 5131 (aka Typar). 1.25 oz/sq yd spunbonded polypropylene; 75% light transmission; about 6 F (3.3 C) degrees of frost protection; lasts for 6 years or more.

Rowcovers at the ready in winter. Photo Wren Vile Rowcover How-to  Lightweight, easy to use and store  To protect against cold, you need thick rowcover. • Hoops keep rowcover  Thinner types are to protect from sticking to frozen from insects - can be doubled leaves and reduce up for cold weather. abrasion.  Hold down edges with bags of • 9- or 10-gauge wire. rocks or sand, plastic jugs of water, or metal or wooden • In winter we use double stakes lying along the edges. wire hoops

We think polypropylene rowcover lasts longer and is tougher than polyester (Reemay) Quick Hoops and Caterpillar Tunnels Quickhoops • Cover more than one bed, close to Caterpillar tunnels the ground. • Usually tall enough to walk in • Can be covered with rowcover • Sometimes narrower than topped by hoophouse plastic for the Quickhoops. 2 beds + 1 path winter. • Plastic or rowcover held down by • Or, once plants are established, if ropes at each hoop. they can withstand cold nights, they may benefit more from clear plastic • Can be used for summer or winter. instead of rowcover over hoops. • No sandbags.

Photo Johnnys Seeds Photo MOFGA

Try a hoophouse (high tunnel)

• A structure of hoops (bows) covered with one or two layers of UV-resistant polyethylene. • Double layer hoophouses use a small electric blower to inflate the space between the layers of plastic • This adds insulation and strength against snow loads and wind. • Crops are usually grown directly in the ground • In winter the soil holds some warmth • Roots can grow deep, crops grow quickly 8. Growing in the winter hoophouse Hoophouses are the place to be in winter, if you are an Asian green.  Night-time protection of two layers of plastic and an air gap – big difference!  September sowings thrive on sunny days and grow surprisingly quickly.  When the daylight falls below ten hours, growth slows down till spring.  For most of the winter, our hoophouse plants are actively growing, not merely being stored for harvest (as happens in colder climate zones and outdoors), so we can continue sowing new hoophouse crops even in December.  Brassicas are the most productive crops in these conditions Photo Wren Vile Our Hoophouse at Twin Oaks

• We have a 30’ x 96’ FarmTek ClearSpan gothic arch hoophouse, with two layers of plastic. • We put it up in 2003, and like many growers our primary goal was growing more winter greens, early tomatoes and peppers. • We divided our hoophouse lengthwise into five 4’ beds and a 2’ bed along each edge. • Our paths are a skinny 12” wide - maximum growing space. Your paths could be wider – you are in charge! • We plant many different cool weather crops in September and October to harvest till April and May September Hoophouse Planting This presentation only covers Asian greens – we grow other crops too! Early September : We clear and add compost to one of the beds and sow tatsoi. At the end of September we clear summer crops from one more bed, add compost and work it in. We transplant Tokyo Bekana and Maruba Santoh at 2 weeks old, Chinese cabbage, Photo November hoophouse beds. pak choy, Yukina Savoy at 3 Ethan Hirsh weeks.

September Outdoor Sowings to Transplant Inside Use hoops and insect netting, and water frequently Sept 15: pak choy, Chinese cabbage, Yukina Savoy, Tokyo bekana, Maruba Santoh Sept 24: Senposai, more Yukina Savoy, mizuna

Transplant into the hoophouse at 2–4 weeks old.

ProtekNet and hoops. Photo Wren Vile

October Hoophouse Planting We try hard to keep all the  10/10, we sow some “filler” space occupied, mostly using Asian greens, to fill gaps later. Asian greens, lettuce, spinach.  10/20 we sow more “filler” 10/2 we sow our first Asian greens brassica salad mix (Harvest  In the fourth week of October, 10/29-12/22) we clear and prepare more beds

Mizuna Photo credit Ethan Hirsh and transplant the Senposai, mizuna, Yukina Savoy at 4 weeks old. For more crops, see my slideshow Hoophouse in Fall and Winter on SlideShare.net

Filler Greens • As well as scheduled plantings, we sow a few short rows of Senposai, Yukina Savoy, Maruba Santoh, Tokyo Bekana and spinach and lettuce to transplant into gaps as soon as they occur. • We simply dig them up, replant where needed, water well. • Alternatively you could keep some plug flats of these plants handy.

Filler greens (and lettuce and spinach). Photo by Kathleen Slattery Persephone days and scheduling winter hoophouse crops  When the daylight length is below 10 hours, little growth happens.  This period depends on your latitude. At 38°N, it’s Nov 20–Jan 20  The slow growth is modified by the time to cool the soil.  In practice, the dates of slowest growth for us are Dec 15–Feb 15.  To harvest in mid-winter, plan to grow a good supply of mature crops before this period. They will provide most of your harvests.  For most of our winter, the hoophouse plants are actively growing, not merely being stored for harvest (as happens in colder climate zones and outdoors)  We continue sowing new crops even in December and January.  Be aware of the increase in days to maturity in winter.

For details, see my slideshow Hoophouse in Fall and Winter on SlideShare.net November Hoophouse Planting Nov 10 we sow more mizuna and Frilly Mustards We then have a fully planted hoophouse. From Nov 10 on we aim to keep a fully planted hoophouse, and as each crop harvest winds down, we immediately replace that crop with another. Nov 11-20 we sow more tatsoi

Bed of tatsoi. Photo Ethan Hirsh December Hoophouse Planting

During December we use the Filler Greens plants to replace casualties and heads of Tokyo bekana, Maruba Santoh, Chinese cabbage, Pak choy, Yukina Savoy each day as soon as we’ve harvested them. We sow our 2nd brassica salad mix 12/9 (Harvest 3/4-3/29) Pak Choy replacing Yukina Pak Choy replacing Yukina Savoy here. Photo Ethan Hirsh Savoy here.

January/February Hoophouse Planting  Until Jan 25, fill gaps with Asian greens, spinach or lettuces as appropriate,  From Jan 25 to Feb 20 fill all gaps everywhere with spinach transplants  From Feb 20, only fill gaps on the outer thirds of the beds, leaving centers free for tomatoes, etc.  Feb 1 we sow Frills #3 and Brassica Salad Mix #3 (Harvest 3/8-4/15)  Feb 9 we sow Brassica Salad Mix #4 (Harvest 3/27-4/30) Filler Greens transplants. Photo Ethan Hirsh

Packing More Crops in Keep the space filled with useful crops. It’s important to know when crops will bolt, and how to plant sensible quantities. Strategies: • Transplant from outside in fall • Filler crops for gaps • Fast catch crops for big gaps • Interplanting to keep the greens later into spring • Follow-on crops, • Succession planting

For details, see my slideshow Hoophouse in Fall and Winter on SlideShare.net December harvests Photo Wren Vile Packing more in – Brassica (Mustard) Salad Mixes • We often mix our own Brassica Salad Mix from leftover random brassica seeds. For a single cut, almost all brassicas are suitable – just avoid and radishes with prickly leaves! • We sow between 10/2 and 11/14 for winter harvest and from 12/4 to 2/12 for March and early April harvests.

Fast Catch Crops Some cool-weather crops mature in 60 days or less. Mostly these Ready in 30–35 days in fall, are greens and fast-growing root longer in winter: crops. Useful if a crop fails, or you • many Asian greens: have a small empty space. Chinese Napa cabbage, Komatsuna, Maruba Santoh, mizuna, pak choy, Senposai, tatsoi, Tokyo Bekana and Yukina Savoy. • radishes (both the fast small ones and the larger winter ones). • Mustard salad mixes

Tatsoi. Credit Wren Vile Packing more in – keep greens for March and April  After 2/20, we harvest the winter crops from the center rows first, plant the new early summer crops down the center, then harvest the outer rows bit by bit as the new crop needs the space or the light. This overlap allows the new crops to take over gradually.  Having greens during the Hungry Tomatoes transplanted in Gap of March and early April is the middle of a lettuce mix very valuable bed. This works with Asian  Our winter and spring crops come greens too. Photo Kathryn to an end in March or early April Simmons

Follow-on Winter Hoophouse Crops (not all of these are Asian greens!) A sequence of different crops occupying the same space over time. Sometimes confusingly called “Succession Planting”. • 11/17: We follow our 1st radishes with 3rd scallions • 12/23: 1st baby brassica salad mix with 5th radishes • 12/31: Some of our 1st spinach with our 2nd baby lettuce mix • 1/15: Our 1st tatsoi with our 4th spinach • 1/16: Our Tokyo Bekana with spinach for planting outdoors • 1/24: Our pak choy & Chinese cabbage with kale & collards for outdoors • 2/1: Our 2nd radishes with our 2nd baby brassica salad mix • 2/1: Our 1st Yukina Savoy with our 3rd mizuna/frilly mustards • 2/1: Some of our 1st turnips with our 3rd baby lettuce mix • 2/1: More of our 1st spinach with dwarf snap peas Succession Planting for  To get harvests starting an equal number of days apart, Continuous Harvests vary the interval between one Tatsoi. Photo Ethan Hirsh sowing date and the next according to growth rate.  As temperatures and day-length decrease in the fall, the time to maturity lengthens – a day late in sowing can lead to a week’s delay in harvesting.  As temperatures and day-length increase after the Winter Solstice, the time to maturity For all the details, see my slideshow shortens – later sowings can Succession Planting for Continuous almost catch up with earlier Harvests on SlideShare.net ones. Our Asian Greens Succession Crops • Mizuna (and other frilly mustards) –#1, transplanted 10/24, harvest 11/5-2/10. –#2, sown 11/10, harvest 1/20-4/3, –#3, sown 3/1, harvested 4/10-5/10 • Tatsoi –#1, sown 9/7, harvest 10/30-12/28. –#2, sown 11/15, harvest 2/12-3/2. • Yukina Savoy –#1, transplanted 10/10, harvest 12/5-1/31. –#2, sown 10/24, harvest 1/8-3/2

Making a Close-Fit Plan Using Graphs A 6 step process (here’s step 1 to step 4): 1. Gather sowing and harvest start and finish dates for each planting of your chosen crop 2. Make a graph for that crop: sowing date along the horizontal (x) axis; harvest start date along the vertical (y) axis. Mark in all your data. Join with a line. Smooth the line. 3. From your first possible sowing date find the first harvest start date. 4. Decide the last worthwhile harvest start date, mark that. Radish Succession Crops Graph with Smoothed Line Step 5 Divide the Harvest Period into a Whole Number of Equal Segments  Count the days from first harvest of the first sowing to the first harvest of the last sowing:10/1–3/18=30+30+31+31+28+18=168  Use the harvest end dates to see roughly how long a patch of radishes lasts (how often you want a new patch coming on line)  Divide the harvest period into a whole number of equal intervals of that length. If we want new radishes every 34 days, we’ll need 5 equal intervals between plantings (34 x 5 = 170).  Five intervals means 6 plantings. (P-I-P-I-P-I-P-I-P-I-P)  The harvest start dates will be 10/1, 11/4, 12/8, 1/11, 2/14,3/20  Draw a horizontal line from each harvest start date to the graph line – see next slide Radish Succession Crops Harvest Start Dates Radish Succession Crops Sowing Dates Step 6. See the Sowing Dates that Match Your Harvest Start Dates  Drop a vertical line down to the horizontal axis from each place that a horizontal line meets your smoothed curve.  Read the planting dates on the horizontal axis at these points  Write these planting dates on your schedule: 9/7, 9/30, 10/28, 11/22, 12/20, 1/27  Sowing intervals are 23, 28, 25, 28, 38 days – longer in Dec-Jan, as the Jan sowing will catch up some with the Dec sowing.  If your planting plans exceed the space you’ve got, simply tweaking to a less frequent new harvest start could free up space to grow something else.  Also consider a gap in radish supply, if other crops could make better use of the space.

Hoophouse Asian Greens Harvest Dates • October: tatsoi. • From November onwards: As October plus brassica salad mix, mizuna, frilly mustards, leaves of Tokyo bekana and Maruba Santoh. • From December: As November plus senposai and Yukina Savoy. • From January: As December • During December: whole plants of Tokyo Bekana, Maruba Santoh. • During January: heads of Chinese cabbage, pak choy. • Having the heading crops in December and January gets us through the slow-growth period. • Most loose-leaf crops last until mid-March or later. • Yukina savoy. Credit Ethan Hirsh Harvesting Methods Don’t harvest frozen crops. Some of these greens are harvested as whole heads; others can be harvested by the leaf and bunched or bagged. Most Asian greens can be grown for baby salad mix. With mizuna and Frills we do a “half buzz-cut,” snipping off leaves on one half of the plant an inch (25 mm) above Tat soi. the ground each time we Photo Ethan Hirsh harvest. Cut and Come Again Harvesting

With baby salad mixes, cut the Tatsoi. Credit Wren Vile plants above the growing point with scissors or shears every 10– 35 days, when the plants are 3”- 4” (8-10 cm) tall. Non-heading and rosette Asian greens can be harvested by the leaf and bunched or bagged. The center will keep growing. Don’t harvest too much: “8 for Later,” leave at least the inner 8 leaves. (Senposai manages OK with 6 leaves)

Harvesting Whole Plants We harvest whole Maruba Santoh and Tokyo Bekana plants in December and Chinese cabbage and pak choy in January. These provide good harvests in the slowest growing time of year. Open rosette types, (tatsoi or the bigger Yukina Savoy) are usually gathered closed and banded with plant ties or rubber bands. We switch from harvesting by the Joi Choi pak choy. Photo Johnny’s Seeds leaf to harvesting whole heads when growth speeds up, and bolting looks likely. Minimize nitrate accumulation in winter In winter, when light levels are low, beware of high levels of nitrates in leafy greens. A health hazard — nitrates can be converted in the body into nitrites, which reduce the blood’s capacity to carry oxygen and may be further converted into carcinogenic nitrosamines.

Photo credit Kathleen Slattery Nitrate Accumulation in Winter • Plants make nitrates during the night, and convert them into leaf material during the day, in the process of photosynthesis. • It takes about 6 hours of sunlight to use up a night’s worth of nitrates. • A small handful of winter leafy vegetables can exceed the acceptable daily intake level of nitrate for an adult, if harvested early in the day

Photo Mark Cain Dripping Spring Gardens Keep Nitrate Levels as Low as Possible  Grow varieties best suited for winter;  Avoid animal fertilizers; use organic compost.  Ensure soil has sufficient P, K, Mg and Mo  Water enough but not excessively;  Provide fresh air as soon as temperatures reach 68°F (20°C), so that carbon dioxide levels are high enough;  Harvest after at least four (preferably six) hours of bright sunlight in winter;  Avoid harvesting on very overcast days;  Avoid over-mature crops and discard the outer leaves. Harvest crops a little under-mature, rather than over-mature;  Refrigerate immediately after harvest, store harvested greens at temperatures close to freezing;  Use crops soon after harvest;  Eat a mixed diet; don’t just eat turnip greens, kale and spinach.

10. Pests : flea beetles Brassica flea beetles are a different species from the ones that plague eggplant, and they can only fly a few hundred yards (meters). o If we get flea beetles, we use Spinosad, an enzyme produced by a soil organism. o Garlic spray, Miller’s Hot Sauce, kaolin and white sticky traps have ProtekNet – get a small mesh been suggested. o You can also catch them with a vacuum cleaner, or inside a bucket coated with Tanglefoot paste (hold the inverted bucket over the plant, shake it and catch the jumping beetles in the goo). o Hb will also control them, as will neem oil or the braconid wasp Microtconus vittatoe Muesebeck.

More Pests o Harlequin bugs are our worst brassica pests. We usually pppppppp pick and kill them. o Aphids are worse in cooler weather (early spring), before their predators have arrived in high enough numbers. We spray the aphids with soap 3 times, 5 days apart, or later in the season we bring in ladybugs. o Caterpillars can be kept off the plants with rowcover or ProtekNet. Bt (Bacillus thuringiensis) will kill caterpillars if rowcovers fail. Bt degrades rapidly in sunlight so is best applied early evening or early morning, whichever seems likely to catch most caterpillars. The beneficial fungus Beauvaria bassiana infects caterpillars, but can get costly. Caterpillars have many natural enemies. In our garden the paper wasps eat caterpillars, and we also have the parasite Cotesia glomerata

Even More Pests o I used to think slugs were an endangered species in Virginia. When we put up our hoophouse, I found we were farming them! Slugs can best be caught at night with a flashlight. (Well, actually with scissors, by flashlight!) o Grasshoppers - We are trying to determine when the young hatch in July, so we know when to be most attentive to keeping them off our plants. o Vegetable weevil larvae have caused trouble in our hoophouse in January. They come out of the soil at night and make holes in the leaves. We have used Spinosad against them with some success.

Diseases . Most of these greens are fast-turnaround crops, so if some get sick, pull them out and move on in life. . If it’s fall you can probably sow some spinach to provide greens without antagonizing the brassica disease gods.

. is perhaps the longest lasting disease, requiring land to be taken out of brassica production for ten years. . Other diseases include various molds and wilts. . See ATTRA’s Cole Crops and Other Brassicas: Organic Production 11. Seed Saving

 If you plan to grow seed of more than one Asian green, carefully choose ones that won’t cross.  Be aware that crops might be wrongly classified.  Also beware of brassica weeds.  For yourself: at least 600 ft (200 m) from other flowering brassicas.  To sell seed: ¼ mile (400 m) with barriers or ½ mile (800 m) without.  Grow at least 120-300 plants, pull out atypical ones, let the rest bolt.  Why so many? Brassicas are crossbreeders, needing genetic diversity  Save seed from at least 60 plants, preferably 125–150.  As the seedpods dry, pull up the plants, and hang them up under cover. Use a fan if it’s humid. Hang plants inside paper sacks to reduce loss of seeds from shattered pods.  Stomp on the bags to break the pods, then winnow and screen the seeds. See the Saving Our Seed Project guide (in the Resources) Seed Crops • Clifton Slade in Virginia overwintered

greens in a hoophouse in zone 7b for seed. • Clif direct seeded 12/1. • On 2/15 he started rolling up the side curtains every day, to vernalize the plants. • 90 days from sowing, 3/1, he had greens. • 100 days from sowing, the plants flowered. Seed matured earlier than outdoors. • Clif had 100 lbs (45 kg) of pods, which gave 30 lbs (14 kg) of cleaned seed. • The yield was double that grown outdoors. • Seeds were bigger than outdoor-grown seed, with good germination

Resources – Asian Greens  Grow Your Own Chinese Vegetables, Geri Harrington, 1984, Garden Way Publishing. Includes the names for these crops in different cultures.  Growing Unusual Vegetables, Hickmott, 2006, Eco-Logic books, UK.  Oriental Vegetables: The Complete Guide for the Garden and Kitchen, Joy Larkham, revised edition 2008, Kodansha, USA  Asian Vegetables, Sally Cunningham, Chelsea Green  The Chinese Kitchen Garden, Wendy Kiang-Spray, 2017, Workman Publishing  Kitazawa Seeds kitazawaseed.com/ Many choices.  Evergreen Seeds helpful clickable list. evergreenseeds.com/asveglis.html  Fedco Seeds fedcoseeds.com/ , Johnny’s johnnyseeds.com/ - good ranges.  Wild Garden Seed. Search under Mustard. wildgardenseed.com  Even’ Star Ice-bred Seeds localharvest.org/even-star-organic-farm-M9994  Good Earth Seed Company (Tsang and Ma International) P.O. Box 5644, Redwood City, California 94063. No English website. Resources - Season Extension  Extending the Season: Six Strategies for Improving Cash Flow Year- Round on the Market Farm Lynn Byczynski  Janet Bachmann, Season Extension Techniques for Market Gardeners, ATTRA, 2005. attra.ncat.org/attra- pub/summaries/summary.php?pub=366  Fall and Winter Gardening Quick Reference, Southern Exposure Seed Exchange, www.southernexposure.com/growing-guides/fall-winter- quick-guide.pdf www.johnnyseeds.com. Growers’ Library, Winter growing guide www.motherofahubbard.com Winter Vegetable Gardening  Solar Gardening: Growing Vegetables Year-Round the American Intensive Way, Leandre Poisson, Gretchen Poisson and Robin Wimbiscus, 1994, Chelsea Green

Resources – More Detail  ATTRA Cole Crops and Other Brassicas: Organic Production attra.ncat.org/attra-pub/summaries/summary.php?pub=27  Saving Our Seed Project carolinafarmstewards.org/wp- content/uploads/2012/05/BrassicaSeedProductionver1_1.pdf an excellent 24-page guide on organic brassica seed production  The Organic Seed Grower, John Navazio, 2014, Chelsea Green  USDA plant database plants.usda.gov/java/  International Code of Nomenclature for algae, fungi, and plants 2018 iapt-taxon.org/nomen/main.php  Missouri Botanical Garden Plant FInder: missouribotanicalgarden.org/plantfinder/plantfindersearch.asp x. Search Brassica rapa, for example  vegvariety.cce.cornell.edu/main/showVarieties.php Search for “Mustard” Optimizing your Asian Greens Production ©Pam Dawling 2019 Twin Oaks Community, Central Virginia Author of Sustainable Market Farming and The Year Round Hoophouse SustainableMarketFarming.com facebook.com/SustainableMarketFarming