Optimizing your asian greens production Dawling 2019

1. 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

2. 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

3. 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 b) Harvesting c) Minimizing nitrate accumulation in winter 10. Pests and diseases 11. Seed saving Pak Choy. Credit Ethan Hirsh

4. 1. Meet the Asian Greens • Huge range of attractive varieties • Quick-growing, bring fast returns • Grow when you normally grow cabbage 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 • Grow all winter in hoophouses in central Virginia Blues Napa Chinese cabbage shown here Credit Ethan Hirsh

5. 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, vitamins A and C, calcium, iron, magnesium and fiber  Help prevent high blood pressure, heart disease, stroke  They contain antioxidants which fight against cancer and protect eyes from macular degeneration Photo Credit Ethan Hirsh

6. 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 weeks after sowing (or you can direct sow) Our hoophouse in November Photo Ethan Hirsh

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

8. Who’s Who – 3 botanical groups 2) The cabbage family, B. oleracea, of European origin Kai-lan, Chinese kale, Toraziroh 3) The Chinese Mustard family, B. juncea Ruby Streaks (shown here, Photo Johnnys Seeds), Golden Frills, Red Rain, Wild Garden Pungent Mix 1) The turnip family, Brassica rapa, of Asian origin a) Brassica rapa var. pekinensis (napa cabbage, michihli, celery cabbage) b) B. rapa var. chinensis (bok choy) 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 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

9. 2. Crops I recommend 1a. Brassica rapa var. pekinensis. Photo Kashruth Council of Canada • A type of wong bok • Very tender, light green leaves • Excellent for stir-fries, pickling • 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 types Napa cabbage

10. 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 speck 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

11. 1a Brassica rapa var. pekinensis Celery cabbage (pe tsai) Photo credit Johnnys Seeds • A fast-growing, looseleaf, non- heading vegetable with light green leaves and white petioles. • Mild flavor, tender texture: can be substituted for lettuce • Can be ready for harvest 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

12. 1a or b Brassica rapa var. pekinensis or var. chinensis Tokyo Bekana • Fast-growing tender chartreuse frilly, leafy plant. • 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 plants can be chopped and lightly cooked Young Tokyo Bekana seedlings in our November hoophouse. Photo Ethan Hirsh

13. 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 bolt resistant Photo Ethan Hirsh

14. 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 to 25°F (-4°C)Photo Johnnys Seeds

15. Pak Choy Red Choi Photo Kitazawa Seeds. http://www.kitazawaseed.com/seed_443 -77.html • Can be picked as individual leaves, for 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)

16. 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

17. Mizuna • 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 Photo Ethan Hirsh

18. 3. Brassica juncea Red Splendor, Ruby Streaks, Golden Frills Johnny’s Red Splendor Ruby Streaks Credit Southern Exposure Seed Exchange Golden Frills

19. 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

20. 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

21. 1e. Brassica rapa var. perviridis or Brassica rapa v. komatsuna Komatsuna • Also known as mustard spinach (so is Pak Choy!), Summer Fest • 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) Photo credit Fothergill Seeds Photo Fothergill Seeds

22. 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

23. Yukina Savoy Outdoors in December, after several nights at 16-17°F (-8 to -9°C)

24. 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

25. Hybrid of 1e. Brassica rapa var perviridis & Brassica oleracea 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

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

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

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

29. • We sow winter radish outdoors on August 4. (China 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 Winter Radish, Including Daikon

30. 3. Crops to try later Small and/or short-lived greens  Hon Tsai Tai, Brassica rapa, (like a purple broccoli raab). Also known as Choy Sum. 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 vegetables. It matures in less than 45 days, a definite plus  Vitamin 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

31. 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 to grow for goats, or to make 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. Mizspoona photo Wild Garden Seeds https://www.wildgardenseed.com

32. 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

33. Chrysanthemum Greens (Shungiku) • Chrysanthemum coronarium. 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. Photos https://plantfreak.wordpress.com

34. 4.Crop Requirements for Asian Greens Similar care requirements to other brassicas, 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,

35. 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 off aphids - could be all the control you need Ruby Streaks mustard with drip irrigation. Photo Ethan Hirsh

36. 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.

37. 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 advantage that thinnings can be used for salads. Photo Kathryn Simmons

38. 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.

39. 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 little as three days in summer temperatures. Bare-root transplants. Photo credit Ethan Hirsh

40. 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

41. 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.

42. 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.

43. Hot Weather Season Extension Insect Netting Shadecloth Asian greens have no problem germinating in temperatures up to 95F (35C) ProtekNet is available from Purple Mountain Organics, duboisag.com and other suppliers. Choose mesh size

44. 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

45. 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

46. Rowcover How-to  Lightweight, easy to use and store  To protect against cold, you need thick rowcover.  Thinner types are to protect from insects - can be doubled up for cold weather.  Hold down edges with bags of rocks or sand, plastic jugs of water, or metal or wooden stakes lying along the edges. We think polypropylene rowcover lasts longer and is tougher than polyester (Reemay) • Hoops keep rowcover from sticking to frozen leaves and reduce abrasion. • 9- or 10-gauge wire. • In winter we use double wire hoops

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

48. 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

49. 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 conditionsPhoto Wren Vile

50. 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

51. 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, pak choy, Yukina Savoy at 3 weeks. Photo November hoophouse beds. Ethan Hirsh

52. 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 September Outdoor Sowings to Transplant Inside ProtekNet and hoops. Photo Wren Vile Transplant into the hoophouse at 2–4 weeks old.

53. For more crops, see my slideshow Hoophouse in Fall and Winter on SlideShare.net October Hoophouse Planting 10/10, we sow some “filler” Asian greens, to fill gaps later. 10/20 we sow more “filler” Asian greens In the fourth week of October, we clear and prepare more beds and transplant the Senposai, mizuna, Yukina Savoy at 4 weeks old. We try hard to keep all the space occupied, mostly using Asian greens, lettuce, spinach. 10/2 we sow our first brassica salad mix (Harvest 10/29-12/22) Mizuna Photo credit Ethan Hirsh

54. 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

55. 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

56. 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

57. 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 Savoy here. Pak Choy replacing Yukina Savoy here. Photo Ethan Hirsh

58. 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

59. For details, see my slideshow Hoophouse in Fall and Winter on SlideShare.net 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 December harvests Photo Wren Vile

60. • We often mix our own Brassica Salad Mix from leftover random brassica seeds. For a single cut, almost all brassicas are suitable – just avoid turnips 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. Packing more in – Brassica (Mustard) Salad Mixes

61. Fast Catch Crops Tatsoi. Credit Wren Vile Ready in 30–35 days in fall, longer in winter: • many Asian greens: 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 Some cool-weather crops mature in 60 days or less. Mostly these are greens and fast-growing root crops. Useful if a crop fails, or you have a small empty space.

62. 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 Gap of March and early April is very valuable Our winter and spring crops come to an end in March or early April Tomatoes transplanted in the middle of a lettuce mix bed. This works with Asian greens too. Photo Kathryn Simmons

63. 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 Follow-on Winter Hoophouse Crops (not all of these are Asian greens!)

64. Succession Planting for Continuous Harvests  To get harvests starting an equal number of days apart, vary the interval between one 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 shortens – later sowings can almost catch up with earlier ones. For all the details, see my slideshow Succession Planting for Continuous Harvests on SlideShare.net Tatsoi. Photo Ethan Hirsh

65. • 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 Our Asian Greens Succession Crops

66. 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.

67. Radish Succession Crops Graph with Smoothed Line

68.  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 Step 5 Divide the Harvest Period into a Whole Number of Equal Segments

69. Radish Succession Crops Harvest Start Dates

70. Radish Succession Crops Sowing Dates

71. 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.

72. 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

73. 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 the ground each time we harvest. Tat soi. Photo Ethan Hirsh

74. Cut and Come Again Harvesting With baby salad mixes, cut the 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) Tatsoi. Credit Wren Vile

75. 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 leaf to harvesting whole heads when growth speeds up, and bolting looks likely. Joi Choi pak choy. Photo Johnny’s Seeds

76. 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

77. 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

78. 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.

79. 10. Pests : flea beetles o Garlic spray, Miller’s Hot Sauce, kaolin and white sticky traps have 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 nematodes will also control them, as will neem oil or the braconid wasp Microtconus vittatoe Muesebeck. ProtekNet – get a small mesh 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.

80. 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 More Pests

81. 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. Even More Pests

82.  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.  Clubroot 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 Diseases

83. 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)

84. Seed Crops • Clifton Slade in Virginia overwintered collard 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

85. 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, Simon 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.

86. 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

87. 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”

88. 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