How to grow tatsoi
Brassica rapa subsp. narinosa · Brassicaceae · Vegetable
When to plant tatsoi: the short answer
Sow outdoors about 4 weeks before the last frost; for a fall crop, sow about 7 weeks before your first fall frost. Seeds germinate in soil from 45 to 85°F, fastest near 70°F.
Cold winters (zone 5): sow Mar 28 – Apr 16, or sow Aug 7 – Aug 24 for a fall crop. Mild winters (zone 9): sow Oct 2 – Oct 19 for fall and winter harvests; the spring window (Jan 18 – Feb 6) closes before the summer heat. Skip the hottest months for tatsoi. See every zone.
Tatsoi is a cool-season vegetable in the Brassicaceae family, almost always sown straight into the ground where it will grow. It wants full sun, though it tolerates a little afternoon shade in hot regions and steady, even moisture. From sowing to first pick is about 35–50 days. It is one of the toughest crops here, standing through hard frost and often improving for it.
Grower’s note: A flat rosette of dark, spoon-shaped Asian greens - mild and quick. Extremely cold-hardy, so it is a top choice for fall and winter cutting under a low tunnel. Harvest whole rosettes or pick outer leaves.
Sowing
Sow about 0.25″ deep, into soil between 45–85°F — germination is quickest near 70°F. It comes up fast (4–8 days). It does not transplant well, so sow it in its final position rather than starting it in pots.
Spacing & layout
Give each plant about 6″ along the row with roughly 10″ between rows. On a square-foot grid that is 4 per square foot. Allow at least 8″ of loose, workable soil for the roots. It grows well in containers at least 6″ deep.
Fitting it to your season
As a cool-season crop, tatsoi does its best growing in the mild weather of spring and fall and tends to bolt or turn bitter in summer heat. A second sowing in late summer, timed to mature as the weather cools, is usually the better crop of the year — and light frost only sweetens it.
Quick facts
Growth stages: how long tatsoi takes to grow
From sowing to first harvest takes roughly 35-50 days (5-7 weeks), with seedlings appearing after 4-8 days in soil around 70°F.
When to plant tatsoi
When to plant tatsoi by USDA zone
Dates worked out from each zone’s typical frost dates for 2026. Find your zone on the zone map, or pick your state below for dates from its own frost dates. Zones 11 and above are frost-free, so timing there depends on heat and rain instead.
| Zone | Last / first frost | Start indoors | Sow or plant out | Fall or second sowing |
|---|---|---|---|---|
| Zone 3 | May 15 / Sep 15 | - | Apr 12 – May 1 | Jul 18 – Aug 4 |
| Zone 4 | May 10 / Sep 25 | - | Apr 7 – Apr 26 | Jul 28 – Aug 14 |
| Zone 5 | Apr 30 / Oct 5 | - | Mar 28 – Apr 16 | Aug 7 – Aug 24 |
| Zone 6 | Apr 15 / Oct 15 | - | Mar 13 – Apr 1 | Aug 17 – Sep 3 |
| Zone 7 | Apr 5 / Oct 25 | - | Mar 3 – Mar 22 | Aug 27 – Sep 13 |
| Zone 8 | Mar 20 / Nov 5 | - | Feb 15 – Mar 6 | Sep 7 – Sep 24 |
| Zone 9 | Feb 20 / Nov 30 | - | Jan 18 – Feb 6 | Oct 2 – Oct 19 |
| Zone 10 | Jan 30 / Dec 15 | - | Dec 28 – Jan 16 | Oct 17 – Nov 3 |
Companions
No strong companions recorded.
Tomato, Pole Bean, strawberry
Common problems
Pests: flea beetle, aphids.
Diseases & disorders: downy mildew, clubroot.
Same family (Brassicaceae)
Rotate these so they don’t follow each other in the same bed year to year.
Questions gardeners ask
When should I plant tatsoi?
Sow outdoors about 4 weeks before the last frost; for a fall crop, sow about 7 weeks before your first fall frost. Seeds germinate in soil from 45 to 85°F. The table on this page gives dates for each USDA zone, and the planting calendar gives dates for your own state or ZIP code.
How long does tatsoi take to grow?
About 35-50 days from sowing to the first harvest. Seeds germinate in 4-8 days, fastest in soil around 70°F.
How much sun does tatsoi need?
It needs six or more hours of sun for the best growth, though four to six hours in partial shade is enough.
What soil pH does tatsoi need?
A soil pH between 6.0 and 7.5. Test before adding lime or sulfur - see the soil pH and testing guide.
How far apart should I plant tatsoi?
Space plants about 6 inches apart in rows 10 inches apart, or 4 per square foot in a square-foot bed. Sow seeds about ¼ inch deep.
Can I grow tatsoi in a container?
Yes. Use a container at least 6 inches deep with drainage holes and a good potting mix, and water more often than you would in the ground.
Figures are typical home-garden ranges from Cooperative Extension planting guides, cross-checked against multiple state sources. Your variety and conditions will vary.