How to grow native basil
Overview
Native basil (Ocimum tenuiflorum) is a warm-climate aromatic herb grown for its spicy, clove-like leaves and flowers. It thrives in heat and humidity, producing best when regularly harvested to prevent flowering.
Varieties
- Tulsi (Holy Basil) — The most common form in Australia, with purple stems and a strong clove scent; used in teas and Ayurvedic remedies.
- Lemon Basil — A citrus-scented variant with pale green leaves; excellent in salads and fish dishes.
Soil Preparation
Prefers slightly acidic to neutral soil (pH 6.0–7.5) with good drainage. Add well-rotted compost or aged manure before planting. Avoid heavy clay soils; improve with sand or raised beds if needed.
Growing Guide
Plant in full sun with well-drained soil enriched with compost. Space 30–40 cm apart. Sow seed 5 mm deep, or transplant seedlings after the last frost. Water regularly to keep soil moist but not waterlogged; reduce watering in winter. Pinch out growing tips at 15 cm to encourage bushiness.
Sowing
Sow seeds 5 mm deep in seed-raising mix, 20–30 cm apart. Germinates in 7–14 days at 20–25°C. Direct sow after frost or start indoors 6 weeks before transplanting. Keep soil warm and moist until emergence.
Care
Feed every 4–6 weeks with a balanced liquid fertiliser (e.g., seaweed or fish emulsion) during active growth. Pinch out flower buds to prolong leaf production and keep plants bushy. Prune lightly after each harvest to encourage new branching.
Companion Planting
Grow near tomatoes, capsicum, and chives to repel pests and enhance flavour. Avoid planting near sage or fennel, which can inhibit growth. Attracts bees and beneficial insects.
Common Pests & Risks
Aphids and spider mites are common in dry conditions; spray with neem oil or a strong water jet. Whitefly can appear on undersides of leaves; use yellow sticky traps or insecticidal soap. Avoid overwatering to prevent fungal root rot.
Harvesting
Harvest leaves from 8 weeks after planting, picking regularly before flowers appear. Cut stems just above a leaf pair to promote new growth. For best flavour, harvest in the morning after dew dries.
In the Kitchen
Use fresh leaves in salads, stir-fries, and curries; add to hot dishes just before serving to preserve flavour. Store in a damp paper towel in the fridge for up to a week. Freeze leaves in oil for longer storage.
Troubleshooting
Yellow leaves: overwatering or poor drainage—reduce water and improve soil. Brown leaf edges: underwatering or heat stress—increase water and mulch. Leggy growth: insufficient light—move to full sun. Stunted growth: cold temperatures—protect from frost or wait for warmth. Flowering too early: stress from heat or drought—pinch off and water more.