When to Plant Radish in Sydney — Warm Temperate Guide

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

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

S = Seed Tray   T = Transplant   D = Direct Sow

Current Growing Conditions

Soil temperature: 19.3°C (optimal range: 8–30°C) ✓ Ready to plant

How to Grow Radish in Warm Temperate Australia

When to Plant

Plant year-round. Peak quality from March-October. Summer sowings are possible but bolting is common.

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)

Warm Temperate Growing Tips for Radish

Recommended Varieties

  • Cherry Belle
  • French Breakfast
  • Sparkler
  • Black Spanish
  • Daikon

Key Challenges

  • Flea beetle damage to seedlings
  • Bolting in summer
  • Slow growth in cold winter

Pro Tips

  • Autumn and spring are the sweet spots for perfect radishes
  • Use insect mesh to exclude flea beetles and cabbage moths
  • Winter sowings grow slowly but produce excellent, sweet roots

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.

Common Radish Pests in Warm Temperate Zones

Insect Tunneling — Risk: MODERATE (score: 46/100)

Organic prevention: Avoid planting brassicas in the same spot consecutively. Remove crop debris. Water regularly (flea beetles prefer dry conditions). Interplant with non-brassica crops. Trap cropping with mustard can dr

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