When to Plant Radish in Cairns, Tropical Guide

Sow April to July. Right now in September it is out of season. The next sowing month is April.

Published · Last reviewed · By Garden Buddy
Growing advice is reviewed by hand. Planting dates, current conditions and prices on this page update daily.

This Radish guide is written for the Tropical zone, which takes in Cairns, Townsville and Darwin. Somewhere else? Your postcode picks the right one.

Not your zone? Brisbane Sydney Melbourne Canberra Alice Springs Perth

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

Radish

Photo: Wikimedia Commons

Radishes are the fastest-growing root vegetable, with some varieties ready in as little as 4 weeks. They are ideal for beginners, succession planting, and filling gaps between slower crops. Summer, winter, and oriental types offer year-round harvesting potential across most Australian zones.

Planting Calendar for Tropical

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
- - - D D D D - - - - -

S = Seed Tray   T = Transplant   D = Direct Sow

Want a nudge when it is Radish sowing time in Cairns?

One email a week with what is worth planting in the Tropical zone right now, Radish 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: 21.4°C (optimal range: 8–30°C) ✓ Ready to plant

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

How to Grow Radish in Tropical Australia

When to Plant

Plant year-round, but best results from March-August (dry season). Summer sowings bolt quickly in heat and long days. Daikon types suit the tropical dry season well.

Soil
Friable, well-drained soil with good moisture retention. Avoid heavy clay. Compost or aged manure improves results but do not use fresh manure which causes forking.
pH Range
6.0-7.0
Sunlight
Full sun in cool months; light afternoon shade in summer to prevent bolting
Spacing
5cm apart, 25cm between rows
Watering
Consistent moisture is critical. Radishes grown with irregular water become woody, pithy, and hot. Water lightly every 1-2 days in dry weather. Mulch to retain soil moisture.

Companion plants: Lettuce, Spinach, Carrot (as trap crop for flea beetle), Peas, Nasturtium

Avoid planting near: Hyssop, Other brassicas (to reduce shared pest load)

Tropical Growing Tips for Radish

Recommended Varieties

  • White Icicle
  • Cherry Belle
  • French Breakfast
  • Daikon (Oriental winter radish)

Key Challenges

  • Rapid bolting in summer heat
  • Flea beetle and caterpillar pressure year-round
  • Pithy roots in hot weather

Pro Tips

  • Focus on the dry season for best quality roots
  • Harvest early (3-4 weeks) before roots become pithy
  • Use shade cloth (30-50%) for summer sowings

Harvesting Radish

When ready: Round varieties: shoulder visible at soil level, 2-3cm diameter. Pull one to check. Summer types: harvest at 4-6 weeks before they become pithy. Winter/daikon types: harvest at 8-10 weeks when 15-25cm long.

How to harvest: Grasp foliage near the crown and pull gently. Water the bed beforehand if soil is dry. For daikon/winter types, loosen soil alongside the root with a fork first.

Where to next

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

Also worth sowing in the tropical zone this September: Lemongrass, Ginger, Cucumber and Basil.

The pest most likely to find your radish: Cabbage White Butterfly.

Supermarket Price

Current average retail: $14.95/kg (12-month range: $9.95–$16.00)

Grow your own and save on grocery bills.

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Common Questions About Radish

When do you plant radish in Australia?

It depends on your climate zone, not the calendar month alone. Planting months by zone:

Does radish grow all year round in Cairns?

No. In the Tropical zone the planting months are Apr to Jul. 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 Tropical zone, Cairns is its reference city.