Mizuna
Brassica rapa var. nipposinica
Also known asJapanese mustard greens · Kyona · Kyouna · Spider mustard · Water greens
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 4–9 (winter low around -34°C)
- Frost
- frost hardy
- Season
- cool (spring/fall)
Growing systems
Root mass: light.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| Rockwool (Mineral wool) | alkaline until pre-soaked | very high | low |
| Expanded clay pebbles (LECA) | neutral / inert | low | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Net pot, no medium (Bare-root) | - | - | - |
| Soil-based mix (Potting soil) | varies | high | high |
Nutrient demand by stage
NPK ratios are relative weights. EC targets shift through the plant's life.
| Stage | N | P | K | EC (mS/cm) |
|---|---|---|---|---|
| seedling | 1 | 1 | 1 | 0.6 |
| vegetative | 3 | 1 | 2 | 1.4 |
Aquaponics suitability
Compatible
Fish waste provides enough nitrogen for healthy growth. Supplemental potassium, calcium, and iron may still be needed depending on fish stocking density.
Care notes
One of the easiest and most productive hydroponic Asian greens. EC 1.0-1.8 mS/cm. pH 6.0-7.0. Temperature: 10–22°C (cool-season; more heat-tolerant than lettuce before bolting). Moderate light (DLI 10-15 mol/m2/day). Any hydroponic system works. From seed to baby leaf: 3-4 weeks. Full-sized rosettes: 5-7 weeks. Harvest outer leaves for cut-and-come-again production over 6-8 weeks. The frilly leaf texture makes mizuna a salad-mix staple; it adds volume and a mild peppery accent without overwhelming other flavours. Succession plant every 2-3 weeks. Red and purple types ('Red Knight', 'Ruby Streaks') carry anthocyanin and add colour contrast in blends. Pest pressure tends to be lower than on other brassicas. For commercial salad-mix growers mizuna is a core crop: fast, attractive and in steady demand from restaurants and retailers.