General
Cauliflower is a cool-season brassica grown for its compact, edible curd (the ‘head’). It is more sensitive to stress than many brassicas: irregular watering, heat spikes, cold snaps, or nutrient shortages can cause tiny premature heads (‘buttoning’) or loose ‘riced’ curds. Many modern cultivars are self-blanching (inner leaves naturally cover the head); older types may need manual blanching to keep heads white and tender. Choose earlies for summer harvest and mid/late cultivars for autumn. Maintain steady growth from germination to harvest for best quality.
Light
Full sun (6–8 hours daily).
Soil type
Moisture-retentive yet well-drained, fertile loam with plenty of organic matter. Lime if pH < 6.5.
Water requirement
Consistent moisture, roughly 25–40 mm per week; never let the soil dry out during head formation.
Nutrient requirement
Heavy feeder: steady nitrogen early, then balanced feed with adequate potassium and micronutrients (boron, molybdenum).
Precultivation
Sow 4–6 weeks before outdoor planting. Seed depth 0.5–1 cm in trays at 20–24°C; germination typically 4–8 days. After emergence, grow on cooler at 12–16°C with strong light to prevent legginess. Pot up to 5–8 cm cells when first true leaves appear. Keep evenly moist and feed lightly with a balanced, organic liquid fertilizer. Harden off 7–10 days before planting by gradually exposing to outdoor conditions, avoiding hard frost. Early crops: start mid–late Feb for planting in April/May; autumn crops: sow March–April for planting May–June.
Planting
Plant when days are reliably above ~8–10°C and danger of hard frost has passed. Spacing: 50–60 cm between plants, 60–70 cm between rows (wider for large-headed types). Soil should be fertile, firm, and at pH 6.8–7.2 to reduce clubroot; incorporate well-rotted compost and, if needed, garden lime well before planting. Water the planting holes, set transplants slightly deeper than in the pot, and firm soil around stems. Use insect netting immediately after planting to exclude cabbage butterflies and moths. Row covers or fleece help protect from cold and root flies early on.
Pruning
No pruning. Only remove damaged or yellowing outer leaves. For non-self-blanching varieties, tie the largest outer leaves loosely over the head when it reaches 5–8 cm across to keep it white and prevent sun discoloration.
Maintenance
Keep soil evenly moist with mulch (straw/leaf mold) to buffer temperature and reduce weeds. Side-dress with nitrogen-rich organic fertilizer 2–3 weeks after planting and again at head initiation. Avoid surges: steady feeding is better than occasional high doses. Ensure micronutrients: boron deficiency causes hollow stems/brown curds; molybdenum deficiency causes ‘whiptail’ (narrow leaves). Apply balanced organic fertilizers or seaweed feeds if deficiencies are common. Pest management: use fine insect mesh (0.8 mm) against cabbage white butterfly, diamondback moth, aphids, and flea beetles. Collar barriers deter cabbage root fly. Rotate crops and maintain a high pH to reduce clubroot; avoid overwatering heavy soils. Weed regularly but shallowly to protect roots.
Harvest
Harvest when heads are firm, compact, and 10–20 cm across, before curds begin to loosen. Cut with a sharp knife leaving several jacket leaves to protect the head. Cool promptly; refrigerate unwashed for 1–2 weeks. For staggered harvests, sow/plant in small batches 2–3 weeks apart. Some cultivars may produce small side shoots after the main head is cut, but this is not consistent.
Common issues
Buttoning (tiny heads) from stress: transplant shock, cold <10°C, drought, or poor fertility—avoid by steady growth, protection, and regular feeding. Ricing/loose curds from heat or overripeness—harvest promptly and provide shade/cool soil with mulch. Yellowing/browning curds from sun exposure—blanch by tying leaves. Clubroot: swollen roots and stunting—raise pH to 7.0–7.2, improve drainage, use clean transplants, rotate 4–7 years, avoid infected plots. Cabbage pests: prevent with insect mesh, encourage beneficials, remove caterpillars by hand. Nutrient disorders: boron or molybdenum deficiencies—apply micronutrient-inclusive organic feeds if soil tests indicate need.
Rotation schedule
Rotate brassicas on a 4–6 year cycle. Example 4-bed sequence: 1) Legumes (peas/beans) → 2) Brassicas (cauliflower/others) → 3) Fruiting crops (tomato, squash) → 4) Roots/leafy (carrot, beet, spinach), then back to legumes. Do not follow or precede other brassicas closely; incorporate compost before brassicas and lime after root/leaf phases if pH drifts below 6.8.
Pollination
Not applicable (harvested before flowering).
Companion plants
Celery, dill, chamomile, onions, garlic, leeks, marigold (Tagetes), nasturtium, peas.
Incompatible plants
Fennel, strawberries, tomatoes, pole beans; avoid planting next to other brassicas if managing pests and disease spread.
