When to Plant Basil in Sydney, Warm Temperate Guide
Soil temperature is modelled from Open-Meteo forecast (Sydney), not a live sensor.
What this month normally looks like in Warm Temperate
In October the Warm Temperate zone normally runs 24°C by day and 13°C overnight, with about 66 mm of rain over 7 or 8 wet days. The coldest October night on record across the zone was -1.5°C, so a late frost is not out of the question. Averages 1991 to 2026, 153 postcodes, SILO.
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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.
- Planting window
- Sep to Feb
- Days to harvest
- 60 days
- Sun
- Full sun
- Water
- Regular
- Spacing
- 25 cm apart
- Soil pH
- 6.0–7.0
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.
Published · By GardenBuddy.au
Planting dates, current conditions and prices on this page update daily.
Photo: Wikimedia Commons
Planting Calendar for Warm Temperate
- Jan S/T
- Feb T
- Mar -
- Apr -
- May -
- Jun -
- Jul -
- Aug -
- Sep S
- Oct S/T
- Nov S/T
- Dec S/T
S = Seed Tray T = Transplant D = Direct Sow
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How to Grow Basil in Warm Temperate Australia
- Soil
- Rich, well-drained soil with plenty of compost. Warm soil is critical.
- Salt
- Moderately sensitive. Copes with a little salt, but the harvest drops on salty bore water.
- 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.
- Good companions
- Tomato, Marigold, Capsicum, Lemongrass, Potato
- Keep away from
- Rosemary (different water needs), Rue, Sage, Thyme (different water needs)
Warm Temperate Growing Tips for Basil
Recommended Varieties
- Genovese
- Large Leaf Italian
- Thai basil
- Purple 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
Pests and problems for Basil in Warm Temperate
- Aphids and Fungal Issues Low
- Fusarium Wilt Use disease-free seed. Rotate planting locations. Grow in containers with fresh potting mix each season. Watch
- Common Garden Snail Watch
- Slugs Watch
- Basil Downy Mildew Space plants for maximum airflow. Water at base only, never overhead. Morning watering so foliage dries quickly. Choose resistant varieties... Watch
Organic prevention (Aphids): Avoid excess nitrogen. Companion plant with marigolds. Check plants regularly.
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.
Storing and preserving basil
How to keep it
- Pesto (freezing). Blend 2 cups basil, 1/2 cup olive oil, 1/3 cup pine nuts or macadamias, 2 cloves garlic, 1/2 cup parmesan. Freeze in ice cube trays, then transfer to bags. Omit cheese for longer storage. Add fresh when thawing. Keeps: 6-12 months frozen.
- Freezing in oil. Chop leaves finely, pack into ice cube trays, cover with olive oil. Freeze. Pop cubes into labelled bags. Drop directly into hot pans for cooking. Keeps: 6 months frozen.
- Drying. Hang small bunches upside down in dark, dry, well-ventilated area for 1-2 weeks. Or dehydrate at 35C for 4-6 hours. Note: dried basil loses significant flavour compared to fresh or frozen. Keeps: 12 months in airtight jar.
- Basil-infused vinegar. Pack clean basil leaves into sterilised bottle. Cover with warm white wine vinegar. Seal and store in dark place for 2-4 weeks. Strain and rebottle. Keeps: 12 months.
- Herb butter. Blend 250g softened butter with 1 cup finely chopped basil, pinch of salt. Roll in cling wrap into log shape. Refrigerate or freeze. Slice rounds as needed. Keeps: 2 weeks refrigerated, 3 months frozen.
What basil costs in the shops right now, retailer by retailer, updated daily.
What members get
- Soil and weather from your nearest station
- An email when it's time to sow
- Your own garden plan, including planning from a photo
- Price history and price alerts
- Pest risk alerts for your area
- Full salt and canning detail
Common 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 Feb, Sep to Dec
- Cool Temperate (Melbourne): Jan, Sep to Dec
- Cold / Highland (Canberra): Jan, Oct to Dec
- Arid / Semi-Arid (Alice Springs): Jan to Feb, Aug to Dec
- Mediterranean (Perth): Jan to Feb, Aug to Dec
Can you grow basil all year round in Sydney?
No. In the Warm Temperate zone the planting months are Jan to Feb, Sep to Dec. Outside that window it either bolts, sulks or gets cut down by the weather.
When should I plant Basil in Sydney?
Wait until nights stay above about 12C before planting out, as cold soil sets basil back. Plants blacken with the first cool nights of May.
What soil temperature do Basil need?
Basil germinate best when soil temperature is between 18°C and 35°C.
How do I know when Basil are ready to harvest?
Begin harvesting when plants have 6+ sets of leaves. Harvest before or at first sign of flower buds for best flavour.
What are the best Basil varieties for Sydney?
Recommended varieties for the Warm Temperate zone include: Genovese, Large Leaf Italian, Thai basil, Purple basil.
What grows well with Basil?
Good companion plants for Basil include: Tomato, Marigold, Capsicum, Lemongrass, Potato.
Are basil salt tolerant?
Only a little. Basil are moderately sensitive to salt, so the harvest drops on salty bore water. Mix salty water with rainwater, and mulch the bed.
Which zone am I in?
Type your postcode into the box near the top of the page and it 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.