Radish Seeds

How to Grow Radish

The essential guide to growing radish (Raphanus sativus) from seed; with notes on germination, cultivation, harvest and even kitchen uses.

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At-a-glance: the radish tribe

• Summer/Salad radish – round or torpedo roots ready in under a month. Crisp, lightly peppery; eat raw, quick-pickle or grate over tacos.
• Winter radish – big Black Spanish, Watermelon and similar roots for cool-season sowings. Dense flesh and a fuller bite; great roasted, in stews or fermented.
• Oriental/Daikon – long white, green-shouldered or pink batons. Mild, juicy and versatile: shred for sushi, stir-fry, pickle or add to kimchi.
• Seed-pod “Rat-tail” radish – grown for crunchy green pods with a wasabi kick; toss into salads or tempura-fry.

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Ave. Seeds per Gram: 80 – 110 seeds

Germinating Temperature: 10 – 25 °C; expect emergence in 3 – 6 days.

Feed Requirements:

• Moderate feeder.
• Work mature compost into the top 5 cm of soil.
• Excess nitrogen = lush tops, skinny roots; keep moisture even to avoid pithy or hot flesh.

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Growing Notes:

Climate & Timing

• Cool regions can sow salad types every 2 – 3 weeks from early spring, to early autumn to ensure a constant supply of fresh radish.
• In temperate Australia skip the height of summer unless you can guarantee constant watering; winter radish go in Feb–Mar.
• Sub-tropics: main sowings Apr–Aug; cool zones can continue under cloches into Oct.
• Winter radish are best sown early to mid autumn as they prefer cooler weather.

Spacing & Depth

• Drill seed 1 cm deep.
  • Salad types: 3 – 4 cm apart in rows 20 cm apart.
  • Winter/daikon: thin to 10 – 15 cm in rows 30 cm apart.
• Radish make first-rate “catch crops”: sow between slower brassicas – you’ll eat the roots before neighbours need the space.

Variety Selection

• Choose globe reds like ‘Cherry Belle’ for speed,
• ‘French Breakfast’ for crunch,
• 'Daikon' for bulk fermenting, or
• colourful heirlooms (eg. 'Watermelon') for salad flair.

General Care

• Mulch lightly once seedlings appear.
• Water when the top 2 cm of soil dries – rapid, steady growth gives the sweetest, mildest roots.

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Common Problems & Pests:

• Flea beetles pepper leaves – exclude with row covers.
  
• Aphids cluster on flower stalks – hose off or apply eco-oil.
• Hot, dry spells or overcrowding cause bolting and woody centres; keep sowings thin and moist.
• Clubroot in wet, acidic soils distorts roots – raise pH to 6.5–7 and improve drainage.
• Water regularly as sporadic heavy watering can cause roots to split.

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Harvesting Notes:

When to Harvest

• Salad radish: 20 – 35 days after sowing, when roots are 2 – 3 cm across.
• Winter/daikon: 6 – 10 weeks, before skin cracks.

How to Harvest

• Grip foliage at soil line, twist and pull; or lift gently with a hand-fork in heavy soils.
• Remove tops to 1 cm to retain crunch.

Storage & Use

• Refrigerate salad radish in a perforated bag for up to two weeks.
• In colder areas winter and daikon roots can be kept in the ground and harvested as needed.
• Leaves are edible – sauté like spinach.
• Let a few plants bolt for zesty green seed pods or to save your own seed.

Enjoy the fastest “seed-to-salad” crop in the veggie patch – so quick it’ll make your head rad-ish!