How to grow tatsoi
Family Brassicaceae. Hardy to USDA hardiness zone 3a+ (U.S. Department of Agriculture). Full sun to part shade. Ready in 40-50 days.
Sun
Full sun to part shade
Spacing
8-10 in
Days to harvest
40-50 days
Hardiness
Zone 3a+
What growers actually recorded
Loading zone 7b results…
When to plant tatsoi
- Direct sow: ~-4 weeks after last frost.
Companion plants for tatsoi
Plant with: Onion, Lettuce, Radish.
Avoid near: Other brassicas in the same bed.
Common pests & problems
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
Cold-hardy to the mid-20s F: a great crop for a low tunnel through early winter.
When to plant tatsoi 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 tatsoi
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
- Rosette reaches 4-6 in across with dark, glossy spoon-shaped leaves.
- Harvest whole rosette by cutting at the base, or pick outer leaves individually.
- Cold snaps flatten the rosette tighter to the ground; that is a normal cold-weather habit, not a problem.
Storing & keeping
Refrigerate unwashed in a perforated bag at 32-40°F for about a week. Holds slightly longer than lettuce due to its thicker leaf but still best eaten fresh.
What to expect
Per plant: 4-8 oz per rosette
Per sq ft: 2-4 rosettes per sq ft
Troubleshooting tatsoi
Leaves riddled with small holes
Likely cause: Flea beetles
What to do: Row cover from sowing through early growth.
Bolts in warm weather
Likely cause: Heat above 75°F
What to do: Grow in cool seasons; tatsoi is notably more cold-hardy than heat-tolerant.
Varieties worth growing
Standard Tatsoi
The common dark-green spoon-leaf type, reliable and widely available.
Yukina Savoy
A larger, savoyed-leaf relative sometimes sold alongside tatsoi for the same cool-season use.
Growing tatsoi in containers
6-8 in pot; compact rosette habit suits window boxes and small containers well.
Nutrition
Sulforaphane, glucosinolates, vitamin K, calcium. Brassicas are the vegetable powerhouse.
Common questions
How cold-hardy is tatsoi really?
It tolerates hard frosts into the low 20s°F and is often grown under row cover through winter in zone 6 and colder.
Can I use tatsoi like spinach?
Yes, its texture and mild flavor cook down similarly to spinach and it can substitute directly in most cooked recipes.
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.