How to grow radicchio
Cichorium intybus · Asteraceae · Vegetable
When to plant radicchio: the short answer
Start seeds indoors about 5 weeks before your last spring frost; plant out about 2 weeks before it; sow outdoors about 2 weeks before the last frost; for a fall crop, sow about 11 weeks before your first fall frost. Seeds germinate in soil from 45 to 80°F, fastest near 68°F.
Cold winters (zone 5): plant out Apr 9 – Apr 26, or sow Jul 10 – Jul 27 for a fall crop. Mild winters (zone 9): sow Sep 4 – Sep 21 for fall and winter harvests; the spring window (Jan 30 – Feb 16) closes before the summer heat. Skip the hottest months for radicchio. See every zone.
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
Growth stages: how long radicchio takes to grow
From sowing to first harvest takes roughly 60-100 days (9-14 weeks), with seedlings appearing after 5-10 days in soil around 68°F.
When to plant radicchio
When to plant radicchio by USDA zone
Dates worked out from each zone’s typical frost dates for 2026. Find your zone on the zone map, or pick your state below for dates from its own frost dates. Zones 11 and above are frost-free, so timing there depends on heat and rain instead.
| Zone | Last / first frost | Start indoors | Sow or plant out | Fall or second sowing |
|---|---|---|---|---|
| Zone 3 | May 15 / Sep 15 | Apr 3 – Apr 17 | Apr 24 – May 11 | Jun 20 – Jul 7 |
| Zone 4 | May 10 / Sep 25 | Mar 29 – Apr 12 | Apr 19 – May 6 | Jun 30 – Jul 17 |
| Zone 5 | Apr 30 / Oct 5 | Mar 19 – Apr 2 | Apr 9 – Apr 26 | Jul 10 – Jul 27 |
| Zone 6 | Apr 15 / Oct 15 | Mar 4 – Mar 18 | Mar 25 – Apr 11 | Jul 20 – Aug 6 |
| Zone 7 | Apr 5 / Oct 25 | Feb 22 – Mar 8 | Mar 15 – Apr 1 | Jul 30 – Aug 16 |
| Zone 8 | Mar 20 / Nov 5 | Feb 6 – Feb 20 | Feb 27 – Mar 16 | Aug 10 – Aug 27 |
| Zone 9 | Feb 20 / Nov 30 | Jan 9 – Jan 23 | Jan 30 – Feb 16 | Sep 4 – Sep 21 |
| Zone 10 | Jan 30 / Dec 15 | Dec 19 – Jan 2 | Jan 9 – Jan 26 | Sep 19 – Oct 6 |
Companions
Lettuce, Endive & Escarole
No strong antagonists recorded.
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.
Questions gardeners ask
When should I plant radicchio?
Start seeds indoors about 5 weeks before your last spring frost; plant out about 2 weeks before it; sow outdoors about 2 weeks before the last frost; for a fall crop, sow about 11 weeks before your first fall frost. Seeds germinate in soil from 45 to 80°F. The table on this page gives dates for each USDA zone, and the planting calendar gives dates for your own state or ZIP code.
How long does radicchio take to grow?
About 60-100 days from sowing to the first harvest. Seeds germinate in 5-10 days, fastest in soil around 68°F.
How much sun does radicchio need?
It needs at least six to eight hours of direct sun a day.
What soil pH does radicchio need?
A soil pH between 6.0 and 7.0. Test before adding lime or sulfur - see the soil pH and testing guide.
How far apart should I plant radicchio?
Space plants about 8 inches apart in rows 12 inches apart, or 4 per square foot in a square-foot bed. Sow seeds about ¼ inch deep.
Can I grow radicchio in a container?
Yes. Use a container at least 10 inches deep with drainage holes and a good potting mix, and water more often than you would in the ground.
Figures are typical home-garden ranges from Cooperative Extension planting guides, cross-checked against multiple state sources. Your variety and conditions will vary.