How to Grow Radish

Growing guide

Overview

Radish is a fast-growing cool-season root vegetable that can go from seed to harvest in as little as 22 days. Growers love it for quick returns, easy succession planting, and compact growth in small beds or containers. It needs full sun, even moisture, and loose, well-drained soil to form crisp, mild roots.

Soil & planting prep

Radishes grow best in loose, loamy or sandy, well-drained soil with a pH around 6.0-7.0. Remove stones and break up clods before planting, and mix in a light amount of compost rather than high-nitrogen fertilizer. Sow seeds 1/2 inch deep and thin to 1-2 inches apart in rows 6-12 inches apart.

When to plant

Direct sow outdoors 4-6 weeks before your last spring frost, as soon as the soil can be worked; light frost will not hurt young radishes. For a late crop, sow again about 6-8 weeks before your first fall frost, usually in late summer. Avoid hot midsummer planting because heat causes bolting and woody roots.

How to plant

1. Work the soil 6-8 inches deep in a full-sun spot, removing stones and breaking up clods so roots can expand easily.
2. Sow seeds 1/2 inch deep and about 1 inch apart, in rows 6-12 inches apart or scattered in a container.
3. Water gently after sowing and keep the seedbed evenly moist until seeds sprout, usually in 4-7 days.
4. Thin seedlings when true leaves appear so plants stand 1-2 inches apart, giving roots room to round out.
5. Sow a new short row every 2 weeks for continuous harvest, but pause during the hottest part of summer.

5 common mistakes to avoid

• Leaving radishes in the ground too long makes them woody, pithy, and hot; check at the 22-to-30-day mark and pull them as soon as the roots are about 1 inch across.
• Skipping thinning leads to crowded, thin, or misshapen roots; sow thinly and thin seedlings to 1-2 inches apart soon after germination.
• Using high-nitrogen fertilizer or rich manure pushes leafy tops instead of roots; rely on light compost and avoid extra nitrogen.
• Letting the soil dry out or swing between dry and wet causes split, pithy, or overly pungent roots; keep the bed evenly moist, especially in warm weather.
• Sowing in hot midsummer often triggers bolting and woody roots; plant in cool early spring or late summer, and skip the hottest weeks.

Harvesting & storage

Harvest radishes when the shoulders push up at the soil line and roots are about 1 inch across, usually 22-30 days after sowing. Pull them by the greens, brush off soil, and remove the tops before storing. Refrigerate roots in a loose bag or covered container for about 1-2 weeks.

Companion planting

Good companions include lettuce, peas, and cucumbers. Radishes are also commonly sown with carrots as a fast marker row because they germinate before the slower carrot seed.

Growing in containers

Radishes grow well in containers. Use a pot that holds at least 3 gallons of soil and is at least 6 inches deep, fill it with loose, well-drained potting mix, and keep it in full sun with consistent moisture.

Pro tips

Direct sow in early spring or late summer. Succession plant every 2 weeks for continuous harvest. Pull before they get woody. Great as a companion plant to mark slow-germinating rows.