Radicchio is a biennial or perennial grown for its leaves, ready to start cutting about 85 days after sowing. It's hardy across USDA zones 3 through 10 and stands up to deer. Its mid summer flowers are a moderate draw for honeybees and native bees, even though the leaves are the prize. Once it comes in, a single planting keeps producing for a couple of weeks, so you harvest over time rather than all at once.
Zones
3-10
pH Range
4.5-8.3
Sun
Full Sun
Days to Maturity
85
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What Radicchio is
Radicchio grows as a biennial or perennial and reaches around a foot at maturity. It blooms blue in mid summer. It's also deer-resistant.
How to grow Radicchio
Radicchio grows in USDA zones 3 through 10 and is ready to harvest about 85 days after planting. Radicchio does best in full sun — at least 6 hours of direct sun a day — and soil from pH 4.5 to 8.3, on well-drained ground. It needs around 1,300 growing degree days to mature and a growing season of at least 90 frost-free days, which is why climate matters as much as soil.
USDA Zones
3-10
USDA PHZM 2023
Soil pH
4.5 - 8.3
USDA PLANTS Database
Sun
Full Sun
plant_species_v5.csv
Drainage
well (dry spells)
plant_species_v5.csv
Frost Tolerance
42.8°F
plant_species_v5.csv
Days to Maturity
85 days
Radicchio / chicory convention; cool-season; head forms after cold trigger.
OSU-PNW; Johnny's
GDD Required
1300+
plant_species_v5.csv
Mature Height
1 ft
plant_species_v5.csv
Frost-Free Days
90+
plant_species_v5.csv
Start the season right
Plant radicchio in full sun with at least 6 hours of direct sun, once the soil has warmed and frost risk has passed.
Match the soil
Radicchio prefers pH 4.5 to 8.3 (USDA PLANTS Database). A quick soil test from your local Extension lab tells you whether to add lime or sulfur to land in band.
Water steadily
Keep the root zone evenly moist through establishment. A 2–3 inch mulch layer holds moisture without waterlogging.
Harvest at maturity
Radicchio is ready about 85 days after sowing (OSU-PNW; Johnny's). Cut the outer leaves as you need them — frequent harvest keeps new growth coming.
Good to know
Good news for pet owners — radicchio isn't known to be toxic to dogs or cats. (Source: ASPCA.)
Radicchio offers moderate value to bees and other pollinators. (Source: Xerces Society, Pollinator Partnership.)
Where Radicchio thrives
On hardiness alone, radicchio grows across most of the country — its range (USDA zones 3 through 10) is unusually wide. Zone is only the starting point, though: the soil pH, drainage, and frost dates on your specific land decide how well it actually does.
Zones 3–10·Where Radicchio growsOpen map →
On USDA hardiness-zone overlap, Radicchio can grow in these states:
See if Radicchio will thrive on your land
Zone averages are a start. Your exact soil pH, drainage, sun exposure, and frost dates shape whether radicchio actually takes — we score it against the real conditions at your address.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Frequently Asked Questions
Can I grow Radicchio in my zone?
Radicchio grows in USDA hardiness zones 3 through 10 (USDA PHZM 2023). Zone is one factor — soil pH, drainage, and frost dates on your specific parcel also shape whether it takes.
How long does Radicchio take to grow?
Radicchio is ready to harvest about 85 days after planting (OSU-PNW; Johnny's). Your local frost dates and soil temperature move that window earlier or later.
When should you plant Radicchio?
Most growers plant radicchio after the last spring frost, once the soil has warmed, leaving enough of the season for its 90-day frost-free need. Your local frost dates set the exact window — a Growable Ground report reads them for your address.
How much sun does Radicchio need?
Radicchio needs full sun — a spot that catches at least 6 hours of direct summer sun a day. In more shade it still grows, but usually gives a smaller, later crop. The catch is that a yard rarely gets even light everywhere — a fence, the house, or one tall tree can quietly take those hours. A Growable Ground report reads the real sun-hours across your land, canopy and buildings included, so you can pick the brightest bed before you plant.
What soil does Radicchio need?
Radicchio prefers soil pH 4.5 to 8.3, on well-drained ground (USDA PLANTS Database). Your report scores your parcel's actual soil against that using USDA SSURGO data.
Does Radicchio attract pollinators?
Yes — radicchio's flowers are a solid nectar source for honeybees and native bees (Xerces Society, Pollinator Partnership).
Is Radicchio safe for pets?
Radicchio is not known to be toxic to dogs or cats based on available data (ASPCA). Always supervise pets around new plantings.