When to Plant Basil in Sydney — Warm Temperate Guide
Photo: Wikimedia Commons
The king of summer herbs. Sweet basil (O. basilicum) is the standard culinary variety, but Thai basil (O. basilicum var. thyrsiflora), lemon basil (O. x citriodorum), and purple basil (O. basilicum 'Purpurascens') each bring distinct flavours. Extremely frost-sensitive - even a light frost kills it dead. Thrives in warm conditions across most of Australia from spring through autumn.
Planting Calendar
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| S/T | S/T | T | — | — | — | — | — | S | S/T | S/T | S/T |
S = Seed Tray T = Transplant D = Direct Sow
Current Growing Conditions
Soil temperature: 19.3°C (optimal range: 18–35°C) ✓ Ready to plant
How to Grow Basil in Warm Temperate Australia
When to Plant
Seed trays Aug-Dec. Transplant Sep-Jan. Do NOT rush - cold soil kills basil. Wait until night temps above 12C consistently.
- Soil
- Rich, well-drained soil with plenty of compost. Warm soil is critical.
- pH Range
- 6.0-7.0
- Sunlight
- Full sun (minimum 6 hours). More sun = more essential oils = more flavour.
- Spacing
- 25cm apart, 40cm between rows
- Watering
- Regular, consistent watering. Basil wilts dramatically when dry but recovers quickly. Water at base, not overhead, to reduce fungal issues. Morning watering preferred.
Companion plants: Tomato, Capsicum, Chilli, Marigold
Avoid planting near: Rue, Sage, Common Thyme
Warm Temperate Growing Tips for Basil
Recommended Varieties
- Genovese
- Large Leaf Italian
- Thai basil
- Purple basil
- Lemon basil
Key Challenges
- Late cold snaps in October can kill transplants
- Season shorter than subtropics
- Downy mildew in humid years
Pro Tips
- Patience in spring - basil planted in warm soil overtakes early plantings in cold soil
- Grow against north-facing brick wall for radiant heat
- Cover with fleece if unexpected cold snap forecast
Harvesting Basil
When ready: Begin harvesting when plants have 6+ sets of leaves. Harvest before or at first sign of flower buds for best flavour.
How to harvest: Pinch or cut stems just above a leaf pair - this encourages two new shoots from that node. Never strip more than 1/3 of plant at once. Harvest in morning after dew dries when essential oil concentration peaks.
Common Basil Pests in Warm Temperate Zones
Organic prevention: Avoid excess nitrogen. Companion plant with marigolds. Check plants regularly.
Supermarket Price
Current average retail: $33.36/kg (range: $25.00–$59.00)
Grow your own and save on grocery bills.
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