When to Plant Basil in Perth, Mediterranean Guide

Sow now in Mediterranean Soil 15.6°C, best 18–35°C. Still too cold.

Soil temperature is modelled from Open-Meteo forecast (Perth), not a live sensor.

What this month normally looks like in Mediterranean

In October the Mediterranean zone normally runs 22°C by day and 10°C overnight, with about 38 mm of rain over 6 or 7 wet days. The coldest October night on record across the zone was -0.2°C, so a late frost is not out of the question. Averages 1991 to 2026, 19 postcodes, SILO.

Jump to section
  1. Planting calendar
  2. How to grow
  3. Local tips and varieties
  4. Pests and problems
  5. Harvesting
  6. Storing and preserving
  7. Other zones and related crops
  8. Common questions

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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.

Planting window
Aug 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.

Basil

Photo: Wikimedia Commons

Planting Calendar for Mediterranean

  • Jan T/D
  • Feb D
  • Mar -
  • Apr -
  • May -
  • Jun -
  • Jul -
  • Aug S
  • Sep S/T
  • Oct S/T/D
  • Nov S/T/D
  • Dec T/D

S = Seed Tray   T = Transplant   D = Direct Sow

Want a nudge when it is sowing time?

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.

How to Grow Basil in Mediterranean 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)

Members see the exact salt threshold, how much harvest it loses as salt rises, and what to grow instead. See what members get

Mediterranean Growing Tips for Basil

Recommended Varieties

  • Genovese
  • Large Leaf Italian
  • Thai basil
  • Lemon 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

Pests and problems for Basil in Mediterranean

Members see each pest score and pest risk alerts for your area. See what members get

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

Browse the full pest library →

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.

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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

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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:

Can you grow basil all year round in Perth?

No. In the Mediterranean zone the planting months are Jan to Feb, Aug to Dec. Outside that window it either bolts, sulks or gets cut down by the weather.

When should I plant Basil in Perth?

A summer herb. Plant seedlings once nights stay above about 12 degrees (late September in Perth, October in Adelaide) and keep sowing through summer.

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 Perth?

Recommended varieties for the Mediterranean zone include: Genovese, Large Leaf Italian, Thai basil, Lemon 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 Mediterranean zone, Perth is its reference city.