How to grow radish
Raphanus sativus · Brassicaceae · Vegetable
Radish is a cool-season vegetable in the Brassicaceae family, almost always sown straight into the ground where it will grow. It wants full sun, though it tolerates a little afternoon shade in hot regions and steady, even moisture. From sowing to first pick is about 22–30 days. It handles frost well and a light freeze often improves the flavour.
Grower’s note: The classic marker crop and quick filler. Sow a short row every 10 days - a single big sowing all matures at once and then goes pithy and hot.
Sowing
Sow about 0.5″ deep, into soil between 40–85°F — germination is quickest near 70°F. It comes up fast (3–7 days). It does not transplant well, so sow it in its final position rather than starting it in pots.
Spacing & layout
Give each plant about 2″ along the row with roughly 6″ between rows. On a square-foot grid that is 16 per square foot. Allow at least 6″ of loose, workable soil for the roots. It grows well in containers at least 6″ deep.
Fitting it to your season
As a cool-season crop, radish does its best growing in the mild weather of spring and fall and tends to bolt or turn bitter in summer heat. A second sowing in late summer, timed to mature as the weather cools, is usually the better crop of the year — and light frost only sweetens it.
Quick facts
When to plant radish
Companions
Carrot, Lettuce, Cucumber, Pea, Spinach
No strong antagonists recorded.
Common problems
Pests: flea beetle, cabbage root maggot, aphids.
Diseases & disorders: clubroot, scab, downy mildew.
Same family (Brassicaceae)
Rotate these so they don’t follow each other in the same bed year to year.
Figures are typical home-garden ranges from Cooperative Extension planting guides, cross-checked against multiple state sources. Your variety and conditions will vary.