How to grow Radish in Australia

Where to plant

Grow radishes in loose, fine soil, worked to about 20 to 30 cm deep and free of stones, so the roots can swell evenly. They grow in sun, and appreciate part shade in warm weather. Radishes are quick and small, so they fit between slower crops and along bed edges, and grow in containers of almost any size.

As members of the cabbage family, radishes share brassica pests and diseases, so rotate them with other brassicas.

• South East Queensland, the Northern Rivers and Sydney: sow from March to September; summer heat makes them bolt.
• Melbourne: radishes can be sown in most months; March to September gives the best roots.
• Adelaide and Perth: sow from March to September and avoid January and February.
• Canberra: sow from September to March; winter sowings fail in cold soil.
• Hobart: sow from August to March, a row every fortnight.
• North Queensland and Darwin: sow in the dry season, May to September. Radishes bolt in wet season heat.

Choosing a variety

• Round salad radishes, in colours from bright red to pink, white and purple, are the quickest, ready in a few weeks.
• Black Spanish and other winter radishes are larger and slower, and are sown for the cool season.
• Daikon, the long white Asian radish, is best grown in the cool season and has its own guide.
• Edible-podded radishes are grown for their spicy seed pods rather than their roots.

How to plant

1. Sow seed direct, about 1 cm deep, in rows about 15 cm apart. Mixing the fine seed with sand helps spread it evenly.
2. Keep the soil moist. Seedlings appear in about a week.
3. Thin seedlings to about 2.5 to 5 cm apart as soon as they can be handled. Crowded radishes rub against each other and go to seed instead of forming roots.
4. Sow a short row every two to three weeks for a steady supply.

Watering and feeding

Keep the soil evenly moist. Dry spells slow growth and make radishes woody and hot, and a heavy soaking after a dry spell splits them. Water well in warm, dry weather, especially in containers.

Radishes need little feeding in reasonable soil. Avoid high-nitrogen fertiliser, which grows leaves at the expense of the root.

Pruning and care through the year

• Thin early and keep weeds down, as radishes compete poorly.
• Cover with fine insect mesh if flea beetles riddle the leaves.
• Do not let them sit in the ground too long; they soon turn pithy and woody.

Harvesting

Most salad radishes are ready when the roots are about 2.5 to 3 cm across at the soil surface, three to five weeks after sowing. Pull one to test before harvesting the rest. Grasp the leaves at the base and pull straight up.

Pick promptly, as radishes left too long split or turn woody and hot. Cut off the leaves and keep the roots in the fridge for up to a week.

Growing in pots

Radishes are one of the easiest crops for pots and troughs. Any container at least 15 cm deep works for round types; keep the mix evenly moist.

Using it

Eat radishes raw in salads and on buttered bread, slice them into slaws, or pickle them. Roasting mellows their bite.

Saving seed

Leave a few healthy plants to flower and form seed pods. Young green pods are edible and peppery. Let the rest dry on the plant, then collect the seed and store it dry.