How to grow radicchio

Cichorium intybus · Asteraceae · Vegetable

Radicchio is a cool-season vegetable in the Asteraceae family, grown either from a direct sowing or from transplants. It wants full sun (six or more hours of direct light) and steady, even moisture. From sowing to first pick is about 60–100 days. It handles frost well and a light freeze often improves the flavour.

Grower’s note: Chicory grown for tight, wine-red heads. Summer heat makes it harsh; cool fall weather and a light frost sweeten it and deepen the colour. Some heirloom types need cutting to the crown once so a firm second-growth head forms.

Sowing

Sow about 0.25″ deep, into soil between 45–80°F — germination is quickest near 68°F. It comes up fast (5–10 days). For an early crop, start seed indoors about 5 weeks before your last spring frost and grow it under bright light.

Spacing & layout

Give each plant about 8″ along the row with roughly 12″ between rows. On a square-foot grid that is 4 per square foot. Allow at least 10″ of loose, workable soil for the roots. It grows well in containers at least 10″ deep.

Fitting it to your season

As a cool-season crop, radicchio 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 radicchio

Companions

Common problems

Pests: aphids, slugs.

Diseases & disorders: downy mildew, bottom rot.

Same family (Asteraceae)

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.