Cool 17 Asian Greens

layout: base.njk title: "Asian Greens (Bok Choy, Tatsoi, Mizuna, Gai Lan)" plantName: "Brassica rapa varieties" category: "Cool Season Crops" description: "Growing guide for Asian Greens (Bok Choy, Tatsoi, Mizuna, Gai Lan) in West Virginia Zone 6b/7a" tags: planting-guide

Type: Annual/Biennial (grown as annual)
Family: Brassicaceae (Cruciferae)
Sun: Full sun to part shade (4-6 hours minimum, afternoon shade in warm weather)
Water: Moderate to high (1-1.5" per week, consistent moisture)
Soil pH: 6.0-7.5 (optimal 6.5-7.0)
Hardiness: Zones 2-11 (cold hardy variety-dependent, many can overwinter)

📅 Planting Calendar (WV Zone 6b/7a)

Method	Timing	Notes
Start indoors	February 15 - March 31; July 1 - August 1	4-6 weeks before transplant. Spring and fall crops. Sow 1/4" deep at 60-75°F. Germination in 3-7 days. Transplants well.
Direct sow	March 15 - May 30; August 1 - October 15	Soil temp 45-85°F optimal. Sow 1/4" deep, thin to 6-12" depending on variety. Spring and fall crops. Fall superior—cooler, less bolting.
Transplant	March 25 - May 15; August 15 - October 1	Harden off 5-7 days. Space 6-12" apart. Tolerates light to moderate frost (many varieties to mid-20s°F).
Days to maturity	30-60 days	Baby greens: 25-30 days. Full size: 40-60 days. Very fast crop.
Succession plant	Every 2-3 weeks spring and fall	For continuous harvest. Stop during peak summer heat. Resume in late summer for fall/winter harvest.

🌱 Expected Yield

Per plant: Baby greens: 2-4 oz. Full size: 0.5-2 lbs depending on variety.
Per 10' row: 10-25 lbs (depends on variety and harvest style).
Per season: With succession planting: 30-60 lbs per 10' row annually.

🌿 Growing Conditions

Soil: Well-drained, fertile loam high in organic matter and nitrogen. Asian greens are moderate to heavy feeders. Loose, moisture-retentive soil. pH 6.5-7.0 optimal. Amend with 3-4" compost before planting. Raised beds excellent.
Fertilizer: Moderate to heavy nitrogen feeder. Apply composted manure or extra compost at planting (2-3 tbsp per 10' row). Side-dress with compost or nitrogen fertilizer every 3-4 weeks. Consistent fertility promotes rapid, tender growth.
Companions: Excellent with radishes, carrots, onions, dill, mint. Fast-growing, good for intercropping. Dill repels pests. Avoid planting near other brassicas if space allows.
Avoid: Plant away from strawberries, other brassicas (shared pests). Rotate 3 years away from brassicas.
Pests: Flea beetles (major pest—row covers essential, especially for young plants), aphids (hose off, insecticidal soap), cabbage worms (Bt, row covers), slugs (diatomaceous earth, hand-picking).
Diseases: Generally disease-resistant due to fast growth. Downy mildew (improve airflow, avoid overhead watering), white rust (reduce humidity), bacterial soft rot (harvest carefully). Fast maturity often outpaces disease.

🏺 Heirloom Varieties (5-10+)

Bok Choy (Pak Choi, Chinese Cabbage)

'Joi Choi'

Source: Johnny's Selected Seeds (johnnyseeds.com), Baker Creek Heirloom Seeds (rareseeds.com)
Days: 45 days
Notes: Hybrid, F1. Large, white stems, dark green leaves. Slow bolting. Sweet, mild flavor. Excellent for stir-fry, soup. Heat tolerant for bok choy. All-America Selections winner. Reliable.

'Black Summer'

Source: Johnny's Selected Seeds, Baker Creek
Days: 48 days
Notes: Hybrid, F1. Dark green leaves, white stems. Heat tolerant. Slow bolting. Sweet, tender. Good for summer harvest. Uniform. Popular with market growers.

'Shanghae'

Source: Seed Savers Exchange, Baker Creek, Johnny's Selected Seeds
Days: 45 days
Notes: Traditional green bok choy. Spoon-shaped green leaves, white stems. Sweet, mild. Cold tolerant. Classic for Chinese cuisine. Reliable producer.

'Red Choi'

Source: Baker Creek, Johnny's Selected Seeds
Days: 50 days
Notes: Hybrid. Purple-red stems and veins, green leaves. Beautiful color. Mild, sweet. Heat tolerant. Adds color to stir-fries. Slower bolting.

Tatsoi (Rosette Bok Choy, Flat Cabbage)

'Tatsoi'

Source: Seed Savers Exchange, Baker Creek, Johnny's Selected Seeds, Southern Exposure Seed Exchange (southernexposure.com)
Days: 45 days
Notes: Heirloom. Dark green, spoon-shaped leaves in rosette pattern. Extremely cold hardy (to 10-15°F, can overwinter). Sweet, mild, mustard-like flavor. Excellent raw or cooked. Beautiful appearance.

'Tatsoi Broadleaf'

Source: Johnny's Selected Seeds, Baker Creek
Days: 40 days
Notes: Larger leaves than standard tatsoi. Same cold hardiness. Sweet, tender. Good for baby leaf production. Fast growing.

Mizuna (Japanese Mustard Greens)

'Mizuna'

Source: Seed Savers Exchange, Baker Creek, Johnny's Selected Seeds
Days: 40 days
Notes: Japanese heirloom. Feathery, serrated leaves. Mild, peppery flavor (less sharp than mustard). Cold hardy (to 10-20°F). Excellent for salads, stir-fry. Self-sows readily. Beautiful texture.

'Red Mizuna'

Source: Baker Creek, Johnny's Selected Seeds
Days: 45 days
Notes: Purple-red leaves, especially in cool weather. Same feathery texture. Mild, peppery. Cold hardy. Beautiful ornamental value. Adds color to salads.

Gai Lan (Chinese Broccoli, Kai-lan)

'Green Lance'

Source: Johnny's Selected Seeds, Baker Creek
Days: 50 days
Notes: Hybrid, F1. Large blue-green leaves, thick stems, small broccoli-like flower heads. Sweet, mild, broccoli-like flavor. Harvest stems, leaves, and flower heads. Cold tolerant. Excellent for stir-fry.

'Chinese Broccoli'

Source: Seed Savers Exchange, Baker Creek, Southern Exposure
Days: 55 days
Notes: Traditional variety. Large leaves, stout stems, white flowers. Sweet, crisp stems. Mild broccoli flavor. Cold tolerant. Traditional for Cantonese cuisine.

Additional Asian Greens

'Komatsuna' (Japanese Mustard Spinach)

Source: Johnny's Selected Seeds, Baker Creek, Seed Savers Exchange
Days: 45 days
Notes: Japanese heirloom. Dark green, oval leaves. Mild, spinach-like flavor with slight mustard bite. Cold hardy. Cut-and-come-again. Excellent for salads, cooking.

'Choy Sum' (Flowering Cabbage)

Source: Johnny's Selected Seeds, Baker Creek
Days: 40 days
Notes: Yellow flowers, tender stems, green leaves. Harvest entire plant when flowering. Sweet, mild. Excellent for stir-fry. Fast growing. Heat tolerant.

'Napa Cabbage' (Chinese Cabbage)

Source: Seed Savers Exchange, Baker Creek, Johnny's Selected Seeds
Days: 55 days
Notes: Large, elongated heads (12-18"). Pale green, crinkled leaves. Sweet, mild. Essential for kimchi, stir-fry. Cold tolerant. Needs consistent moisture. Fall crop best.

📜 Cultural History & Domestication

Domesticated: Asian greens derive from Brassica rapa, domesticated in China over 6000 years ago. Different varieties developed for different uses—leaves (bok choy, tatsoi, mizuna), stems (gai lan), heads (napa cabbage).

Archaeological Evidence: Brassica rapa remains found in Neolithic Chinese sites (4000-3000 BCE). Evidence from Yangtze River valley. Ancient crop in East Asia.

Historical Record: Chinese agricultural texts from 500-1000 CE describe various Brassica rapa cultivars. Bok choy, tatsoi, mizuna developed through centuries of selective breeding in China, Japan. Each region developed distinctive varieties suited to local climates and culinary preferences. Napa cabbage developed in Yangtze River region (15th-17th centuries). Gai lan (Chinese broccoli) traditional in Cantonese cuisine. Mizuna traditional in Kyoto, Japan (Heian period, 794-1185 CE). Tatsoi grown in China for centuries. Asian greens remained confined to Asian cuisine until late 1900s. Asian immigration to Americas brought seeds and culinary traditions. Chinatowns in San Francisco, New York had markets selling Asian greens (1800s-1900s). Mainstream American discovery of Asian cuisine (1970s-1990s) increased demand. Stir-fry became popular home cooking. Salad revolution (1990s-2000s) embraced mizuna, tatsoi in mesclun mixes. Farm-to-table movement valued Asian greens for flavor diversity, rapid growth, cold hardiness. Today Asian greens standard at farmers markets, grocery stores. Different varieties suit different preparations—bok choy for stir-fry, soup; tatsoi for salads, sautéing; mizuna for salads, garnish; gai lan for stir-fry (stems, leaves, flowers all edible); napa cabbage for kimchi, stir-fry, slaw.

Cultural Significance: Asian greens represent culinary diversity—mild (bok choy, napa), peppery (mizuna, komatsuna), bitter-sweet (gai lan). This range adds complexity to meals. Chinese cuisine values balance—Asian greens provide texture contrast (crisp stems, tender leaves), flavor balance (mild greens offset rich, salty dishes). Stir-fry technique perfected for Asian greens—high heat, quick cooking preserves color, texture, nutrients. Gai lan traditional with oyster sauce—classic Cantonese dish. Bok choy essential for many Chinese soups, noodle dishes. Tatsoi's rosette shape beautiful raw—used in upscale salads. Mizuna's feathery leaves add visual texture. Napa cabbage essential for kimchi (Korean fermented cabbage)—kimchi cultural icon, everyday food, ceremonial dish. Kimchi-making (kimjang) UNESCO Intangible Cultural Heritage. Komatsuna Japanese staple—milder than Western mustard greens, used in soups, pickles, sautés. Asian greens' cold hardiness makes them perfect for fall/winter harvest in many climates. Flavor improves after frost (sweetens). This biological adaptation valued by growers. Rapid maturity (30-60 days) makes Asian greens perfect for succession planting, filling garden gaps. Cut-and-come-again harvesting extends yield. Asian greens nutritional powerhouses—vitamins A, C, K, folate, calcium, iron, glucosinolates (anti-cancer compounds). Darker leaves more nutritious. The mild flavor of many Asian greens (compared to Western mustard greens) makes them accessible to people who think they hate bitter greens. Bok choy, tatsoi gateway vegetables. Different textures—bok choy's crunchy stems, tatsoi's tender rosettes, mizuna's feathery frills, gai lan's thick stalks—add interest to meals. Growing Asian greens connects gardeners to global foodways—these vegetables carry centuries of agricultural and culinary wisdom.

🌾 Seed Saving

Method: Asian greens are biennial (Brassica rapa)—require vernalization (cold period) to flower. For seed saving, select best plants, leave in ground over winter (mulch heavily in zone 6b/7a—many varieties cold hardy enough) or dig and store in cool, humid place, replant in spring. In spring, plants send up 3-5' branched flower stalks with clusters of yellow, four-petaled flowers. Flowers are insect-pollinated (bees, flies). Seed pods (siliques) mature 4-6 weeks after flowering, turning from green to tan/brown. Cut stalks when most pods brown but before shattering. Hang in paper bags in dry, ventilated area 2-3 weeks. Thresh by beating bags or rolling stalks. Winnow by pouring between bowls in breeze to separate seeds from chaff.
Isolation distance: 800 feet to 1 mile minimum. Asian greens cross-pollinate readily with other Brassica rapa varieties (turnips, Chinese cabbage, pak choi, broccoli raab, mustard greens—all same species). For pure seed, grow only one B. rapa variety or cage isolated plants with netting and hand-pollinate.
Viability: 4-5 years when stored in cool, dry, dark conditions in airtight containers. Medium-sized seeds store well.
Special notes: Save seed from minimum 5-10 plants to maintain genetic diversity. Select for flavor, bolt resistance, cold hardiness, disease resistance. In zone 6b/7a, many Asian greens overwinter with mulch (tatsoi, mizuna especially hardy). Biennial requirement means seed saving requires two full seasons. Asian greens cross readily with turnips, other B. rapa crops—if growing multiple varieties, isolate or cage. Many Asian greens self-sow readily (mizuna, tatsoi)—volunteers appear next season. This makes seed saving unnecessary for home growers. Let some plants flower, collect seed or let nature reseed. For specific variety preservation, save seed intentionally.

📖 Sources Consulted

Jett, Lewis W. "2026 Garden Calendar." WVU Extension Service.
Ashworth, Suzanne. Seed to Seed: Seed Saving and Growing Techniques for Vegetable Gardeners, 2nd ed. Seed Savers Exchange, 2002.
"Growing Asian Greens in the Home Garden." Ohio State University Extension, HYG-1625-15.
"Asian Greens Production." University of Massachusetts Extension.
"Asian Greens Varieties." Seed Savers Exchange Yearbook. seedsavers.org, 2025.
Baker Creek Heirloom Seeds Catalog. rareseeds.com, 2025.
Johnny's Selected Seeds Grower's Library. johnnyseeds.com, 2025.
Kiple, Kenneth F. and Kriemhild Coneè Ornelas, eds. The Cambridge World History of Food. Cambridge University Press, 2000. (Historical references)
"The Diversity of Brassica rapa." Plants for a Future Database. pfaf.org.

🌾 Natural Soil Amendments (Loop Farmstead Standard)

Only on-farm, regenerative inputs:

Compost: 1-2 inches annually (on-farm production)
Cover crops: Rye + vetch (fall), buckwheat (summer), daikon (compaction)
Wood chips: Pathways only (aged 2+ years for beds)
Fall leaves: Mulch or compost browns
Blood/bone meal: From farm-slaughtered animals
Biochar: Charged with compost tea (permanent carbon)
Wood ash: Light application from wood stove
Eggshells: Crushed/powdered (slow calcium)

❌ Never used: Synthetic fertilizers, mined minerals, gypsum, peat moss

See: natural_soil_amendments_standard.md for complete guide

Added to WV Planting Guide 26155 — The Loop Farmstead