Turnip
Brassica rapa subsp. rapa
Also known asWhite turnip · Garden turnip · Neep · Nabo
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 2–10 (winter low around -46°C)
- Frost
- frost hardy
- Season
- cool (spring/fall)
Growing systems
Root mass: moderate.
Growing media
| Medium | pH effect | Retention | Bacterial surface |
|---|---|---|---|
| Soil-based mix (Potting soil) | varies | high | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Expanded clay pebbles (LECA) | neutral / inert | low | 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 | 0.7 |
| vegetative | 2 | 1 | 3 | 1.8 |
Companion-growing notes
- Heavy uptake of potassium. Co-grown crops with the same demand will end up deficient even at "correct" EC.
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 fastest root crops for hydroponic media beds. 8–12 cm of loose substrate. EC 1.5-2.5 mS/cm. pH 6.0-7.0. Temperature: 10–22°C (cool-season; above 25°C, roots become woody and pungent). Moderate light (DLI 12-18 mol/m2/day). From seed to harvest: 30-45 days for baby types ('Hakurei', 'Tokyo Cross'), 45-65 days for standard types. Direct seed and thin to 5–8 cm. Baby turnips are harvested when roots are 4–6 cm and eaten raw (sliced, with butter and sea salt, or in salads); the sweetness and tenderness of a well-grown baby turnip is a revelation for people who only know the strong, fibrous turnips of traditional cooking. The greens are harvestable throughout growth. Flea beetles are the main pest. For aquaponics growers, turnips offer the fastest root-crop gratification in any media bed.