Mizuna (Brassica rapa subsp. nipposinica)
2 sources cited · Verified
The short answer
- Plant
- Mid March to mid September
- Site
- 5+ hours of sun, soil pH 6.5–7.5
- Biggest risk
- Brassica downy mildew
In the UK, mizunas go in the ground mid March to mid September.
Mizunas (Brassica rapa subsp. nipposinica) — biennial, harvested in its first year as a fast-growing compact plant.
Timing is the decision that matters most in the UK: there are 4 separate regional sowing windows, ranging from mid March in Southern England to mid March in Scotland.
Core growing advice on this page is checked against named horticultural and university-extension sources — see References.
Regional Planting Calendar
| Region | Sow |
|---|---|
| Southern England | mid March to mid September |
| Midlands | mid March to mid September |
| Northern England | mid March to mid September |
| Scotland | mid March to mid September |
Southern England - detail & sources
Harvest to Table gives a spring sowing (about two weeks after last frost) plus a late-summer succession sowing rather than UK-region-specific dates; a window spanning both is applied across all four sub-regions rather than inventing a north/south gradient the sources do not support.
Midlands - detail & sources
Harvest to Table gives a spring sowing (about two weeks after last frost) plus a late-summer succession sowing rather than UK-region-specific dates; a window spanning both is applied across all four sub-regions rather than inventing a north/south gradient the sources do not support.
Northern England - detail & sources
Harvest to Table gives a spring sowing (about two weeks after last frost) plus a late-summer succession sowing rather than UK-region-specific dates; a window spanning both is applied across all four sub-regions rather than inventing a north/south gradient the sources do not support.
Scotland - detail & sources
Harvest to Table gives a spring sowing (about two weeks after last frost) plus a late-summer succession sowing rather than UK-region-specific dates; a window spanning both is applied across all four sub-regions rather than inventing a north/south gradient the sources do not support.
Quick Facts
| Factor | Value |
|---|---|
| Soil pH | 6.5 - 7.5 |
| Sunlight | 5-5 hours direct sun |
| Soil texture | chalk, clay, loam or sand (RHS) |
| Drainage | well-drained |
| Lifecycle | biennial, harvested in its first year as a fast-growing compact plant |
| Edible parts | leaves |
At a Glance
Soil & Growing Conditions
Water: moist but well-drained; prefers cooler conditions especially in summer (RHS)
Soil pH range
Span reflects genuine variation between the cited authorities, not a single agreed figure.
Growth Stages
| Stage | BBCH | Notes |
|---|---|---|
| Sowing | 0 | Sow in spring about two weeks after the last frost, or again near end of summer for autumn/winter harvest; germinates in 4-7 days at 45-85F (Harvest to Table). |
| Establishment | 3 | Fast-growing compact rosette to about 20cm; full sun or part shade, moist well-drained soil (RHS). |
| Baby leaf harvest | 8 | Pick baby leaves 4-6 weeks after germination once 4-6in tall (Harvest to Table). |
| Mature harvest | 8 | Leave to 6-8 weeks for fuller heads; slow to bolt in hot weather, very cold-hardy into winter (Harvest to Table, RHS). |
Harvest & Storage
When to pick: Baby greens from 4-6 weeks after germination, once leaves reach 4-6in tall; fuller heads at 6-8 weeks (Harvest to Table). Very cold-hardy, harvestable well into winter under row covers or cold frames.
Diseases
Pests
Mizuna, Field to Blanched Bunch
References
-
Sow in spring as soon as soil can be worked, about two weeks after the last frost; germinates in soil as cool as 40F (4C), taking 4-7 days at 45-85F (7-29C). Sow every three weeks for succession harvests; grows from seed to maturity in about 40 days. Sow again near end of summer for an autumn/early winter harvest. Harvest begins 3-6 weeks after germination: baby greens at 4-6 weeks once leaves reach 4-6in tall, fuller heads at 6-8 weeks. Extremely cold-hardy, harvestable well into winter under row covers or cold frames; unprotected plants survive light frost to about -6C (21F), row-covered or cold-framed plants to -12C (10F). Grown in USDA zones 3-10. Slow to bolt in hot weather compared to many leafy greens.
-
Hardiness H5 (hardy throughout most of the UK even in severe winters, -15 to -10C). Full sun or part shade. Soil: chalk, clay, loam or sand; moist but well-drained; alkaline or neutral pH; tolerates both exposed and sheltered sites. Height and spread 0.1-0.5m (20cm rosettes noted in first year). Time to maturity 1 year (biennial, but harvested in first year as a fast-growing compact plant). Grow in firm, fertile soil. Oriental greens are usually very hardy but prefer moist, cooler conditions, especially in summer. Propagate by seed. PESTS: susceptible to flea beetle, small white butterfly caterpillars, cabbage root fly, pigeons, snails, mealy cabbage aphid, though damage isn't usually severe once established. DISEASES: may develop brassica downy mildew, white blister, or club root (particularly in previously-cropped soil) -- named directly for this species, not inferred.
2 independent sources are cited for this crop. Where they disagree - soil pH is the clearest case - every figure is preserved rather than averaged into false precision.
Frequently Asked Questions
When should I sow mizunas in the UK?
In Southern England, from mid March. In Scotland, wait until mid March. Treat these as a guide rather than a fixed date — the governing rule is to sow only once frost risk has passed and temperatures are reliably warm enough.
When do I sow mizunas?
Sow mid March to mid September.
What soil pH do mizunas need?
A pH of about 6.5–7.5. That span reflects genuine variation between the authorities we cite rather than a single agreed figure — the References section lists each source's exact range.
What problems affect mizunas?
Our data links 3 diseases and 4 pests to this crop. See the sections above for each one and how to manage it.
Plan next season before the problems start
Most of the advice on this page comes down to timing and spacing — sowing at the right moment, rotating beds, and giving plants enough airflow. The UK Garden Planner lays your plot out month by month so those decisions are already made before the season starts.
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Last verified 2026-08-29
Where To Go From Here
Take this crop from reading into a written plan for your own beds.
Plan the next step
Use the printable SoilCommander planner for your region to turn this guide into sowing dates, bed layouts and weekly garden tasks.