Growing Komatsuna: A Complete Profile
By Growing Home Greens Team · August 10, 2026
Komatsuna is a fast, mild-flavored Asian brassica green, notably more heat- and cold-tolerant than spinach while offering a similar leaf texture and taste, which makes it a useful stand-in during the stretches of the season spinach won’t tolerate.
Direct-seed and succession sow
Direct-seed from spring through midsummer, extending into late fall in mild climates or a protected structure. Sow 15 seeds per foot a quarter inch deep, in rows 12 to 18 inches apart; most varieties don’t need thinning. Succession sow every 7 to 10 days for a steady supply through the season rather than one large planting that all matures at once.
A single-harvest crop
Unlike some Asian greens that regrow after cutting, komatsuna is classified as a heading type, harvested from medium to full size as a single cut rather than picked leaf by leaf over time. Plan the planting schedule around that: more, smaller successive sowings rather than fewer large ones that need repeated visits.
Komatsuna has no well-established companion pairings, and nothing it needs to be kept away from. At 4 plants per square foot, it’s a reliable spinach substitute for the Garden Designer during the hottest and coldest stretches of the growing season.
Source: Asian Greens: Key Growing Information, Johnny’s Selected Seeds.
Companion planting guide for Komatsuna · Find your planting dates
Typically viable in USDA zones 2-11. Not sure your zone? Look it up by ZIP code.
Mature height: 1-1.5 ft
Method: Direct sow: Direct-sow outside. It doesn't transplant well, or doesn't need the extra time indoors.
When to plant komatsuna, by zone
Every zone komatsuna grows in. Pick your zone in the header and it will be highlighted here. Each zone links to its full page.
| Zone | Start indoors | Sow or plant out | Harvest |
|---|---|---|---|
| 2a & 2b | Not usually | May 6–May 13 | Jun 15–Jun 22 |
| 3a & 3b | Not usually | May 16–May 23 | Jun 25–Jul 2 |
| 4a & 4b | Not usually | May 1–May 8 | Jun 10–Jun 17 |
| 5a & 5b | Not usually | Apr 26–May 3 | Jun 5–Jun 12 |
| 6a & 6b | Not usually | Apr 11–Apr 18 | May 21–May 28 |
| 7a & 7b | Not usually | Mar 27–Apr 3 | May 6–May 13 |
| 8a & 8b | Not usually | Mar 11–Mar 18 | Apr 20–Apr 27 |
| 9a & 9b | Not usually | Feb 1–Feb 8 | Mar 13–Mar 20 |
| 10a & 10b | Not usually | Jan 16–Jan 23 | Feb 25–Mar 4 |
| 11a & 11b | Not usually | Dec 18–Dec 25 | Jan 27–Feb 3 |
Harvest dates are about 40 days after the sow or plant-out date.
Zone 2 sows before zone 3 here, which looks wrong and is not. USDA zones rank winter cold, not season length, and zone 2 is mostly interior Alaska, where hard winters come with warm summers. More on what a zone measures.
See exact start-indoors, direct-sow, and harvest dates for your zone →
How many Komatsuna plants fit per square foot?
Spacing: 4 per square foot (square-foot-gardening spacing). Mature height: 1-1.5 ft.
Good companions for komatsuna
- Radish: Radish (including the daikon form) is a documented trap crop for flea beetles, which prefer its mustard oils over other brassicas and can be sacrificed or pulled once infested: the same research cited on the radish page.
Full companion guide, including what to keep away from komatsuna →
Varieties worth considering
- Straight-species komatsuna (Brassica rapa var. perviridis): Johnny's Selected Seeds sells this variety plain, without competing named cultivars; the mild flavor and fast growth are traits of the variety itself. (source)
Why each variety is listed comes from the source shown next to it. We haven't grown these ourselves yet, so treat this as a research-backed starting point, not a personal endorsement. The buy links are separate from those sources: they go to seed suppliers that sell that exact variety, and we may earn a commission on some of them.
Where to buy komatsuna seeds
True Leaf Market (each supplier's komatsuna seeds)
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See it growing
Search YouTube for "growing komatsuna" videos → (a live search, not a hand-picked video; results vary and aren't vetted by us)
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Growing Komatsuna: A fast, mild-flavored Asian brassica green, more heat- and cold-tolerant than spinach while offering a similar leaf texture and taste.
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