When to Plant Basil in Perth, Mediterranean Guide

Sow September to March. Right now in September you can sow.

This Basil guide is written for the Mediterranean zone, which takes in Perth, Adelaide and Bunbury. Somewhere else? Your postcode picks the right one.

Not your zone? Cairns Brisbane Sydney Melbourne Canberra Alice Springs

Also handy: will it frost this week? and what grows in shade.

Basil

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 Mediterranean

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

Want a nudge when it is Basil sowing time in Perth?

One email a week with what is worth planting in the Mediterranean zone right now, Basil included, plus which veg has jumped in price at the supermarket. Free, and you can stop it in one click.

Current Growing Conditions

Soil temperature: 15.9°C (optimal range: 18–35°C) ✗ Outside optimal range

Modelled from Open-Meteo forecast (Perth), not a live sensor.

How to Grow Basil in Mediterranean Australia

When to Plant

Seed trays Aug-Dec. Transplant Sep-Jan. Warm dry summers are ideal for basil.

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

Mediterranean Growing Tips for Basil

Recommended Varieties

  • Genovese
  • Large Leaf Italian
  • Thai basil
  • Lemon basil
  • Purple basil

Key Challenges

  • Water stress in dry summers
  • Need consistent irrigation
  • Wind exposure can damage soft leaves

Pro Tips

  • Excellent basil climate, warm, dry, sunny
  • Drip irrigation for consistent moisture without wet foliage
  • Make pesto in bulk in January when plants are at peak

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 Mediterranean Zones

Aphids and Fungal Issues, risk: LOW (score: 33/100)

Organic prevention: Avoid excess nitrogen. Companion plant with marigolds. Check plants regularly.

View all pest alerts →

Where to next

What basil costs in the shops right now, retailer by retailer, updated daily.

Also worth sowing in the mediterranean zone this September: Ginger, Beetroot, Chilli Peppers and Cucumber.

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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:

Does basil grow all year round in Perth?

No. In the Mediterranean 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 Mediterranean zone, Perth is its reference city.