How to grow napa cabbage
Family Brassicaceae. Hardy to USDA hardiness zone 3a+ (U.S. Department of Agriculture). Full sun to part shade. Ready in 55-80 days.
Sun
Full sun to part shade
Spacing
12-18 in
Days to harvest
55-80 days
Hardiness
Zone 3a+
What growers actually recorded
Loading zone 7b results…
When to plant napa cabbage
- Start indoors: ~5 weeks before last frost.
- Transplant out: ~-2 weeks after last frost.
- Direct sow: ~-6 weeks after last frost.
Companion plants for napa cabbage
Plant with: Onion, Dill, Beet.
Avoid near: Tomato, Strawberry.
Common pests & problems
Cabbage worm, aphid, flea beetle, slugs.
Feeding & fertilizer
N-P-K ratio: High N (10-5-5): heavy feeders
Organic options: Aged manure or compost worked in deep · Blood meal or feather meal side-dress at 3 wks · Fish emulsion every 2 wks
When to feed: Feed heavily every 2-3 weeks. Brassicas want steady nitrogen for tight heads.
Watch for: Pale/yellow leaves = needs N. Loose heads = feed harder next round.
N = nitrogen (leaves), P = phosphorus (roots and flowers), K = potassium (fruit and disease resistance). How to read a fertilizer label →
Grower's tip
Grow it as a fall crop where possible: napa bolts in spring heat but forms a tight, sweet head in cooling fall days.
When to plant napa cabbage in your zone
Free month-by-month sowing and transplanting lists, built from frost dates for your USDA (United States Department of Agriculture) hardiness zone.
Soil & water for napa cabbage
Soil & pH
6.5-7.5: near neutral (raises club-root resistance)
Fertile loam with strong drainage. Firm soil beats fluffy for heading brassicas.
Compost 2 in + 1 cup of alfalfa or feather meal per 10 sq ft. Lime if pH is under 6.5. It also blocks club-root.
Watering
1-1.5 in / week, consistent
Ground-level drip. Uneven water during heading = split heads or bolting.
Lift an edge of the row and check soil at 3 inches. If it clings in a damp ball, hold off. If it crumbles, water until the top 6 inches are evenly moist.
Knowing when to harvest
- Head feels dense and firm to a squeeze, elongated and tightly wrapped.
- Outer leaves still bright, not yellowing, which signals the head sitting too long.
- Harvest before a hard freeze; napa is less frost-hardy than European cabbage.
Storing & keeping
Refrigerate whole, wrapped, at 32-40°F, 95% humidity for 2-3 months, longer than most leafy greens. Also the standard base for napa kimchi, a reliable long-term preservation route.
What to expect
Per plant: 2-4 lb per head
Per sq ft: 1 head per sq ft
Troubleshooting napa cabbage
Fails to form a tight head, stays loose and leafy
Likely cause: Heat above 75°F during head formation
What to do: Time planting so heading occurs in cool fall weather; napa is more heat-sensitive than green cabbage.
Bolts before heading
Likely cause: Cold exposure below 50°F while young
What to do: Start seed indoors and transplant after soil has warmed, avoiding a cold-shock window.
Varieties worth growing
Michihili
Tall, cylindrical head, classic for slicing and cooking.
Bilko
Bolt-resistant hybrid suited to both spring and fall sowing.
Rubicon
Vigorous, disease-resistant hybrid favored for kimchi production.
Growing napa cabbage in containers
5-gallon pot, one plant; needs consistent moisture and fertility that's harder to maintain in a container than a bed.
Nutrition
Sulforaphane, glucosinolates, vitamin K, calcium. Brassicas are the vegetable powerhouse.
Common questions
Is napa cabbage the same species as regular cabbage?
No, napa is Brassica rapa, more closely related to bok choy and turnip, while green and red cabbage are Brassica oleracea.
Why does my napa cabbage split?
Splitting follows the same pattern as round cabbage: heavy rain or irrigation after the head has matured. Harvest promptly once heads feel firm.
Where these numbers come from
- USDA Plant Hardiness Zone Map (2023 revision). Zone assignment and the 30-year normals behind every cold-hardiness figure.
- NOAA NCEI 1991-2020 Climate Normals. Frost dates, growing-season length, and the probability bands on both.
- Cornell, UMN, and UC Davis Cooperative Extension crop guides. Spacing, days to maturity, soil pH targets, and per-plant yield ranges.
- USDA FSIS / FDA Produce Safety guidance. Wash, cure, and cold-storage handling numbers.
Ranges are regional guidance, not a promise for your yard. Your own logged results always override the published range.