When to Plant Basil in Sydney, Warm Temperate Guide
Sow September to March. Right now in September you can sow.
Published · Last reviewed · By Garden Buddy
Growing advice is reviewed by hand. Planting dates, current conditions and prices on this page update daily.
This Basil guide is written for the Warm Temperate zone, which takes in Sydney, Newcastle and Wollongong. Somewhere else? Your postcode picks the right one.
Not your zone? Cairns Brisbane Melbourne Canberra Alice Springs Perth
Also handy: will it frost this week? and what grows in shade.
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 for Warm Temperate
| 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
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Current Growing Conditions
Soil temperature: 17.0°C (optimal range: 18–35°C) ✗ Outside optimal range
Modelled from Open-Meteo forecast (Sydney), not a live sensor.
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.
Where to next
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Open the planting dashboard Join Garden BuddyCommon Questions About Basil
When do you plant basil in Australia?
It depends on your climate zone, not the calendar month alone. Planting months by zone:
- Tropical (Cairns): all year
- Subtropical (Brisbane): Jan to Mar, Aug to Dec
- Warm Temperate (Sydney): Jan to Mar, Sep to Dec
- Cool Temperate (Melbourne): Jan to Mar, Sep to Dec
- Cold / Highland (Canberra): Jan to Feb, Oct to Dec
- Arid / Semi-Arid (Alice Springs): Jan to Mar, Aug to Dec
- Mediterranean (Perth): Jan to Mar, Sep to Dec
Does basil grow all year round in Sydney?
No. In the Warm Temperate zone the planting months are Jan to Mar, Sep to Dec. Outside that window it either bolts, sulks or gets cut down by the weather.
Which zone am I in?
Type your postcode into the box under the heading and the page tells you, and links this crop in your own zone if it differs. Or look it up on the grow zone map. This page is the Warm Temperate zone, Sydney is its reference city.