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.
Radicchio — the short answer
Radicchio: grown in zones 3–10, full sun, pH 4.5–8.3, about 85 days to maturity.
- USDA zones
- 3–10
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Soil pH
- 4.5–8.3
- FAO ECOCROP
- Sun
- Full Sun
- Growable Ground Plant Database
- Days to Maturity
- 85 days
- OSU-PNW; Johnny's
- Frost-kill temperature
- 30.2°F
- FAO ECOCROP
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — each tile names its own row's source, because per-field provenance varies.
Score Radicchio on your exact land.
Zone averages can't see the slope, soil, frost, and sun that decide whether radicchio actually takes — and those shift from one yard to the next. Enter your address and we'll score radicchio against your land's real conditions.
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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
FAO ECOCROP
Sun
Full Sun
Growable Ground plant catalog
Drainage
well (dry spells)
Growable Ground plant catalog
Frost Kill Temperature
30.2°F
Where cold starts killing growing tissue. Not a winter-survival floor — a dormant perennial takes far colder, which its hardiness zone answers.
FAO ECOCROP
Minimum Growing Temperature
42.8°F
Below this it stops growing rather than dies — a pace limit, not a survival limit.
FAO ECOCROP
Days to Maturity
85 days
Radicchio / chicory convention; cool-season; head forms after cold trigger.
OSU-PNW; Johnny's
GDD Required
1300+
Growing degree-days of accumulated warmth it needs to mature — humid summers reach this faster than cool coastal ones.
Growable Ground plant catalog
Mature Height
1 ft
Growable Ground plant catalog
Frost-Free Days
90+
The frost-free stretch it needs start to finish — short-season areas may need an indoor head start.
Growable Ground plant catalog
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 (FAO ECOCROP). 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.
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.
A USDA zone is a 10°F band of average annual extreme winter minimum, so zones 3–10 spans average winter lows from -40°F to 40°F (USDA PHZM 2023). Across the 50 states and DC, that band covers 47 outright and splits 4 more down the middle — and which side of that line your land sits on changes the answer.
Zones 3–10·Where Radicchio growsOpen map →
Where Radicchio stands, state by state
Radicchio is rated for zones 3–10 — a cold floor USDA puts at -40 to -30°F. Across the 50 states and DC, 47 sit fully inside that band, the line runs through 4 more, and 0 sit outside it — and inside every split state, the same line runs on at county grain.
Fully inside zones 3–10
47 states
3 of 47 shown
The line runs through
4 states
- Alaska · zones 1a-9a
- California · zones 4b-11a
- Florida · zones 8b-12a
3 of 4 shown
Radicchio’s band covers part of each of these states — which side of the line your county sits on changes the answer, and each state page draws it.
State zone extents: USDA Plant Hardiness Zone Map (PHZM) 2023. A zone is a 10°F band of average annual extreme minimum temperature, so a state that splits the band contains the boundary — its own page draws the county line, and a parcel report resolves which side your land sits on.
What grows around Radicchio
Growing guides for radicchio
In rotation planning, radicchio counts as a Other — beds recover best when other crops don’t follow each other in the same spot year over year. (Growable Ground derivation — crop-rotation group from botanical family)
Related plants in vegetable
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: Pollinator Partnership.)
Before you harvest radicchio, know your soil
Anything you grow to eat takes up what's in the ground it grows in, so it's worth knowing what's documented near you before you plant radicchio for food. Our free screen reads 9 federal source types across roughly 1.8M indexed sites and shows which sit near your address and which way they drain. It's a screening estimate from public records and proximity — not a soil test — so a nearby record means a soil test is worth it, not that your soil is unsafe.
Your land is one point inside Radicchio's range
This page resolves to the species. Your state page draws the county line, and a report reads the parcel — the soil pH, drainage, sun, and frost dates on your exact ground, which no species average can see.
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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How we know this about Radicchio
The figures above are cited per row, not per site: the pH band names this plant’s own source column, the three temperature figures each carry their own, and days-to-maturity cites the publication that actually lists it. All of it comes from the Growable Ground Plant Database — a compilation over FAO ECOCROP, USDA PLANTS, and university Extension sources, published openly with per-field provenance.
Grounded inUSDA PLANTS Database•USDA PHZM•ASPCA
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 (FAO ECOCROP). 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. (Source: Pollinator Partnership.)
Is Radicchio safe for pets?
Radicchio is not known to be toxic to dogs or cats based on available data. Always supervise pets around new plantings. (Source: ASPCA.)