radicchio (Cichorium intybus), photographi

Can I Grow Radicchio in Montana?

USDA Zones 3a-6b · Plant zone range 3-10

Yes — Strong Match

radicchio is grown in zones 3-10, which covers every zone Montana contains (3a-6b). Whether the season is long enough is the question that remains.

Radicchio in Montana — the short answer

Radicchio in Montana: grown in zones 3–10, full sun.

Plant zones
3-10
Not verified — NC State Extension Gardener Plant Toolbox lists zones 3a–8b
Montana zones
3a-6b
USDA PHZM 2023
Frost window
May 2 - May 13 – Sep 28 - Oct 7
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
59 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
Days to maturity
65 days
Growable Ground Plant Database

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.

Score your parcel · free to start

Your yard isn't the whole zone.

Montana spans zones 3a-6b, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score radicchio against your parcel's actual hardiness, soil, and sun.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

No card required · your parcel report in seconds — read in full free for your first 14 days

Montana is not one climate

A single Montana answer averages 56 counties whose growing seasons are 111 days apart — from 59 frost-free days in Deer Lodge County to 170 in Petroleum County. Which end of that your land sits nearer changes what radicchio can finish before the first hard freeze.

59 daysDeer Lodge County170 daysPetroleum County

The middle half of 56 counties runs 137–158 days, with a median of 150 days — a 111-day span end to end.

Measured across 56 Montana counties. NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.

Where in Montana Fits Best

Even within Montana's zones 3a-6b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for radicchio (USDA PHZM 2023):

Zone Comparison

Radicchio Needs

  • USDA Zones: 3-10
  • Sun: Full Sun
  • Mature size: 1 ft tallWe haven't confirmed this against a published source yet.
  • Picking window: ~14 days of harvestWe haven't confirmed this against a published source yet.
  • Drought tolerance: Medium

Montana Has

  • USDA Zones: 3a-6b
  • Last Hard Freeze (28°F): May 2 - May 13
  • First Hard Freeze (28°F): Sep 28 - Oct 7
  • Annual Rainfall: 10-20 inches
  • Common Soils: Sandy loam, Clay, Glacial till

Plant Zone Range (zones 3-10)

3a
10b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 4.5 – 8.3

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Radicchio in Montana

The frost window

Across Montana, the last spring hard freeze (28°F) clears between May 2 and May 13, and the first fall hard freeze lands between Sep 28 and Oct 7 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 138-day window you can count on — up to 158 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.

When to start the seed

Those dates are when radicchio goes out, not when it starts. It is sown under cover about 4 weeks ahead, so counting back from Montana's late-side last freeze of May 13 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.

Winter standing

Montana runs as cold as USDA zone 3, and no sourced winter-hardiness floor is on record for radicchio, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether radicchio is a permanent planting or a replant-every-spring crop for you turns on your own zone within Montana; check its hardiness range against that before treating it as long-lived ground.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.

Growing Season Fit

Radicchio is grown in zones 3–10, which covers every zone Montana contains (3a-6b). We have no sourced winter-survival figure for radicchio, so this page does not say whether it overwinters here. Montana's typical season runs ~151 frost-free days against the ~90 radicchio needs.

Growing degree days

Radicchio needs ~1300 GDD (base 50°F) to ripen. We haven't confirmed this against a published source yet. The state median runs ~1769 GDD (from PRISM 1991-2020 climate normals), so Montana's typical season clears that easily.

GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.

Soil + Drainage Fit

Radicchio tolerates a wide pH range (pH 4.5-8.3) — 3.8 units, acid ground through alkaline — so soil acidity is rarely what limits it in Montana. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 6 and 7.5 — worth knowing before you decide whether a Montana soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Montana site is heavier clay or sits in a low spot, a raised bed lifts the roots above wet ground, or work in compost.

Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Montana soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Before you plant radicchio for food

Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before radicchio goes in. What follows is Montana’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.

Safe to Grow Here?

What the federal record shows across Montana — and how to grow with it.

Federal record: High

We checked the federal record across Montana — 11,382 documented sites across 7 of the 8 source types we track.

The most significant on record: 124 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Montana carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds of imported, lab-tested soil grow well almost anywhere in the meantime.

Know before you grow — the guide

Sources Checked

across Montana

Severity Distribution

across Montana

High1,851Moderate3,950Low5,581

Highest-Severity Sites

Superfund · Superfund NPL
PFAS Sampling · PFAS Detected
Mining Sites · Past Producer
Mining Sites · Past Producer
Mining Sites · Past Producer

A note from Gnorman

What an experienced grower watches for around here

In and around Montana, two things run higher than the national average across Montana — Mining (4,319 sites) and Brownfields (805 sites). That's not a problem with your land — it's information about it.

Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.

Brownfields: Brownfield sites are former commercial or industrial properties that EPA’s Brownfields program (ACRES) has assessed or funded cleanup on.

Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.

Contact the EPA Brownfields program or the state cleanup agency for this site’s actual assessment/remediation status — ACRES itself does not publish one we can read per site.

Sources: EPA, USGS — 950K documented sites tracked nationwide across 8 federal source types.

What Else to Consider for Radicchio in Montana

The zone range tells you where radicchio is grown — but Montana growers also need to think about:

Very short growing season (60-100 frost-free days)

Low rainfall requires irrigation in most areas

Extreme winter cold (-40F possible)

What to actually do about these — and the constraints that apply to every Montana grower, not just radicchio — is covered on the Montana growing guide.

Where in Montana Radicchio Is Zone-Hardy

Radicchio is rated for USDA zones 3–10. Every one of Montana’s 56 counties sits inside that band — from Daniels County at zone 3b to Sanders County at zone 6a — so winter cold is not what decides this plant anywhere in the state. What is left to vary is your own parcel: slope, shelter and cold-air drainage routinely move a site half a zone either way from the county figure.

Across those 56 counties Montana’s winter-low ladder runs from zone 3b in Daniels County to zone 6a in Sanders County — 2.5 USDA zones of spread, which is 25°F between the two counties’ average coldest night of the year. That is why a statewide hardiness answer is where you start and not where you finish.

The planting window moves with it. Deer Lodge County holds its last hard freeze (28°F) until about Jun 21, while Petroleum County is clear by Apr 25 — 57 days apart. Set radicchio out on your county’s date, not the state’s.

County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F killing freeze — earlier than the folk 32°F "last frost". Radicchio’s zone 3–10 band: Not verified — NC State Extension Gardener Plant Toolbox lists zones 3a–8b. A parcel report resolves your address’s own zone and frost dates rather than its county’s.

Pollinator + Wildlife Value

Radicchio draws honeybees and native bees (moderate value). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, radicchio can only work that bloom inside Montana's frost window — roughly 151 days, opening after the last 28°F freeze (May 2 - May 13) and closing at the first (Sep 28 - Oct 7), per NOAA Regional Climate Centers ACIS, 1991-2020. Pollinator value: We haven't confirmed this against a published source yet.

Montana Cooperative Extension

For Montana-specific cultivar recommendations, planting calendars, and pest pressure for radicchio, the canonical source is Montana State University Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Radicchio native to Montana?

No — the USDA PLANTS Database lists Radicchio as introduced rather than native in the Lower 48, so it is not part of Montana's native flora. It grows here as a garden plant; pairing it with a few Montana natives keeps local pollinators fed too.

Looking for plants that belong here? The Montana growing guide lists plants that USDA PLANTS records growing in Montana and that Kew and NatureServe Explorer both list in its native range, leaving out any that NatureServe flags as exotic there or that our audit holds.

State records: USDA PLANTS Database state-distribution data (presence, not state-level nativity), accessed 2026-10-19.

Common Questions About Growing Radicchio in Montana

When can I plant Radicchio in Montana?

Montana's last spring hard freeze (28°F) clears between May 2 and May 13, and the first fall hard freeze lands between Sep 28 and Oct 7 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Radicchio, so this page does not state whether it overwinters in Montana and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.

What hardiness zone is Radicchio grown in across Montana?

Montana spans USDA hardiness zones 3a-6b (USDA ARS PHZM 2023). Radicchio carries a range of zones 3-10, so the overlap zones are where outdoor growing is most reliable.

How many frost-free days does a typical Montana site have?

A typical Montana site sees ~151 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Radicchio needs 90+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.

Is Radicchio native to Montana?

No — the USDA PLANTS Database lists Radicchio as introduced rather than native in the Lower 48, so it is not part of Montana's native flora. It grows here as a garden plant; pairing it with a few Montana natives keeps local pollinators fed too.

How should I amend the soil for Radicchio in Montana?

Radicchio tolerates pH 4.5-8.3 and well (dry spells) drainage (FAO ECOCROP). That is a 3.8-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Montana site — amend for drainage and organic matter first.

Will Radicchio actually grow on my specific land in Montana?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores radicchio against your address's mapped soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free to start

Check your specific parcel in Montana

State-level data is a sketch. Your Growable Ground report scores radicchio against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.

Three things about your lot that Montana radicchio averages can't show:

Your soil pHYour frost-free days — Montana averages 151Your sun & shade

We read public map data around Montana — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Montana radicchio average

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