Cauliflower
Brassica oleracea var. botrytis
Also known asCauli · Chou-fleur
Environment
The bounded range this crop tolerates.
Climate and zones
- USDA zones
- 3–10 (winter low around -40°C)
- Frost
- tolerates light frost
- Season
- cool (spring/fall)
Growing systems
Root mass: heavy. Thin-channel systems can't hold this crop.
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 | 1 |
| vegetative | 3 | 1 | 2 | 2.2 |
Companion-growing notes
- Heavy uptake of nitrogen, calcium. Co-grown crops with the same demand will end up deficient even at "correct" EC.
- High transpiration. Regular reservoir top-ups needed during fruiting.
Aquaponics suitability
Not recommended
Fish waste alone doesn't supply enough of what this crop demands. Grows in hybrid systems with supplemental dosing, but expect active management.
Care notes
One of the most demanding brassicas for hydroponics, due to a narrow temperature window and sensitivity to stress. Use large containers or media beds with about 20 cm of depth. Hold EC around 1.8-2.5 mS/cm and pH 6.0-7.0. Curd formation needs 15–20°C; above 25°C or below 5°C the plant buttons (premature undersized curds), goes ricey (loose, grainy), or browns, and that tight window is the main difficulty. Give moderate to high light, 17-22 mol/m2/day. From transplant the crop runs 65 to 85 days. Harvest when the curd is 15–20 cm across, compact and white, or the target colour for coloured types; yellow or purple blush on a white curd means light is reaching it, so check the blanching. Steady calcium and boron prevent hollow stem and curd browning. Caterpillars and aphids are common pests. The temperature sensitivity makes cauliflower a fall or winter crop in most setups, and mini varieties such as Snow Crown are faster and more forgiving.