How to grow kale
Overview
Kale is a cool-season brassica grown for its crisp, nutritious leaves. It thrives in mild weather with steady moisture and full sun, making it a rewarding crop for autumn and winter gardens.
Varieties
- Lacinato — Also called 'dinosaur' kale; dark blue-green, crinkled leaves, very hardy in cool seasons.
- Red Russian — Purple-stemmed, flat leaves with red veins; sweet after frost, popular in NZ.
- Curly — Standard curly-leaf kale; vigorous, good for salads and cooking.
Soil Preparation
Kale prefers fertile, well-drained soil with pH 6.0–7.5. Enrich with compost or aged manure before planting; ensure good drainage to prevent root rot.
Growing Guide
Sow kale seeds 1 cm deep in well-drained soil, spacing 30–45 cm apart. Plant in full sun for best leaf production; water regularly to keep soil consistently moist but not waterlogged. In cool climates, start in spring for a summer harvest; in temperate zones, sow in late summer for autumn and winter picking.
Sowing
Sow seeds 1 cm deep, 30–45 cm apart, in rows. Germinates in 5–10 days at 10–20°C. Direct sow or transplant; thin to strongest seedlings.
Care
Feed kale with a balanced liquid fertiliser every 2–3 weeks during active growth. Remove yellowing lower leaves to improve airflow and reduce pest risk; mulch around roots to retain moisture.
Companion Planting
Plant kale near beets, celery, onions, or potatoes to deter pests. Avoid following other brassicas like broccoli or cabbage to prevent soil-borne diseases.
Common Pests & Risks
Common pests include cabbage white caterpillar, aphids, and diamondback moth. Control with netting, hand-picking, or organic sprays like neem oil; encourage beneficial insects.
Harvesting
Harvest kale by picking the lower leaves when they are 10–15 cm long, starting from the outside. Leave the central crown to continue producing; plants can be harvested for several months.
In the Kitchen
Use kale raw in salads, steamed, or sautéed. Store in fridge for up to a week; remove tough stems before cooking. Rich in vitamins A, C, and K.
Troubleshooting
Yellow leaves: nitrogen deficiency or overwatering. Brown edges: heat stress or inconsistent watering. Stunted growth: poor soil or pests. Bolting: hot weather or late planting.