globe artichoke (Cynara scolymus), photographi

Can I Grow Globe Artichoke in Montana?

USDA Zones 3a-6b · Plant zone range 7-11

Unlikely — Zone Mismatch

globe artichoke (zones 7-11) does not overlap with Montana's zone range (3a-6b). Growing outdoors is unlikely without significant protection.

2 zones short — what would close it

Globe Artichoke is hardy to zone 7, and the warmest ground in Montana is zone 5 — 2 zones short. Planted in open ground it will not survive a Montana winter. To grow it here, grow globe artichoke in an earth-sheltered greenhouse — its modeled 2.5-zone lift covers this gap.

An earth-sheltered greenhouse is the lift this needs. How a greenhouse changes what you can grow →

Zone math from 7-11 (plant) against 3-5 (Montana). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['earth_sheltered'] (+2.5 zones) via api/fast_sections.py Unlock Engine v2.

Globe Artichoke in Montana — the short answer

Globe Artichoke in Montana: hardy in zones 7–11, full sun, against a state median of ~151 frost-free days.

Plant zones
7-11
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
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
85 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

Your yard isn't the whole zone.

Montana spans zones 3a-6b, but your yard has its own microclimate — slope, trees, and low spots shift frost and sun across a single parcel. Enter your address and we'll score globe artichoke against your land's actual soil, sun, and frost.

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

No card required · your full report in seconds

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 globe artichoke can finish before the first hard freeze.

59 daysDeer Lodge County170 daysPetroleum County

The middle half of 56 counties runs 137158 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 Globe Artichoke Stands in Montana

Globe Artichoke is rated for zones 711 — a cold floor USDA puts at 0 to 10°F. No Montana county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Montana winters, not about globe artichoke.

Below the zone 7 floor

56 counties

3 of 56 shown

Winter cold is the limit here — the same plant works in a container that comes under cover.

County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.

Zone Comparison

Globe Artichoke Needs

  • USDA Zones: 7-11
  • Frost-Free Days: 210+
  • Sun: Full Sun
  • Picking window: ~60 days of harvest

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 7-11)

7a
11b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.58.3

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 Globe Artichoke 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.

Frost tenderness

Globe Artichoke is frost-tender — FAO ECOCROP puts its killing temperature at 32°F — so set plants out two to three weeks PAST your local last hard freeze, not on it and not on the state's earliest date. The 28°F marker above is when killing freezes stop, not when light frost does. That is the point where cold damages growing tissue, not a winter-survival floor — an established perennial comes through far colder while dormant, which is what its hardiness zone tells you.

When to start the seed

Those dates are when globe artichoke goes out, not when it starts. It is sown under cover about 8 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.

Days to maturity vs. the window

At 85 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 53 days to spare even in Montana's tightest freeze scenario — room for a later start or a second sowing.

Timing tuned to sub-state frost dates — Deer Lodge County, not the statewide average.

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

The zone check says globe artichoke does not survive a Montana winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on Montana under protection.

Frost-free days

Globe Artichoke wants 210+ frost-free days; a typical Montana site sees ~151 (NOAA Regional Climate Centers ACIS, 1991-2020) — 59 days short of what it needs. A typical Montana season does not carry this crop to harvest outdoors, and a gap that size is not one an earlier sowing date or a faster cultivar closes; growing it here means growing it under cover.

Growing degree days

Globe Artichoke needs ~2200 GDD (base 50°F) to ripen. The state median runs ~1769 GDD (from PRISM 1991-2020 climate normals), so Montana's typical season runs short on heat — pick a south-facing site and consider season extension.

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

Globe Artichoke likes near-neutral soil (pH 5.5-8.3). That's the common-ground band across Montana's sandy loam and clay — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6 and 6.5 — 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, raised beds or amendment with compost solve it.

Your land, not the state average

Montana's soils run mostly loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Globe Artichoke needs about 19 inches of workable depth, so it is that horizon — not the surface — you are testing for. That map unit, not the state average, decides how globe artichoke performs.

Check your parcel → Source: USDA NRCS SSURGO.

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 globe artichoke 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 globe artichoke 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 Montana22,453 documented sites across 8 of the 9 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 with clean imported soil grow well almost anywhere in the meantime.

Know before you grow — the guide

Sources Checked

across Montana

Severity Distribution

across Montana

High1,851Moderate14,210Low6,392

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 Nitrate (10,260 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.

Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.

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

Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).

Sources: EPA, USGS1.8M documented sites tracked nationwide across 9 federal source types.

What Else to Consider for Globe Artichoke in Montana

Zone compatibility tells you about winter cold survival — 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)

Growing globe artichoke here specifically

Globe Artichoke sends medium roots and rates to zones 7–11, but much of Montana sits on slow-draining, restrictive ground (SSURGO hydrologic group D) that forks and stunts them.

Loosen a deep, stone-free bed for globe artichoke and break any compacted or hardpan layer before planting. How to handle it →

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

Timing shifts within Montana

Montana isn't one climate. In Deer Lodge County, the last hard freeze (28°F) holds until about Jun 21 — roughly 47 days later than the recorded state median — so plant globe artichoke to your county's window, not the statewide date.

Globe Artichoke needs about 210 days of frost-free season to complete its cycle. No Montana county gives it that outdoors: even Petroleum County, the state’s longest season at 170 frost-free days, falls 40 days short — so it needs transplants, a short-season variety, or covered growing.

Across Montana’s 56 counties the frost-free season runs from 59 days in Deer Lodge County to 170 days in Petroleum County — a spread of 111 days, which is why a single statewide planting date misleads. The median Montana county sees 151 frost-free days, which is 59 days short of what globe artichoke needs — so on a typical Montana parcel this is a transplant-or-protect crop, not a direct-sow one.

County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Globe Artichoke's 210-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.

Pollinator + Wildlife Value

Globe Artichoke draws honeybees, native bees, and butterflies (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, globe artichoke 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.

Montana Cooperative Extension

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

Is Globe Artichoke native to Montana?

No — the USDA PLANTS Database lists Globe Artichoke 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 USDA-documented natives for the state.

Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.

Common Questions About Growing Globe Artichoke in Montana

When can I plant Globe Artichoke 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). Globe Artichoke is frost-tender — its killing temperature is 32°F (FAO ECOCROP — the point where cold damages growing tissue, not a winter-survival floor) — so wait two to three weeks past your site's last hard freeze, when light frost has also stopped, before planting out.

Can Globe Artichoke mature before first frost in Montana?

Yes — Globe Artichoke matures in 85 days (Growable Ground Plant Database), and Montana's dependable hard-freeze-free window runs 138 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 53 days of margin. Plant once the last hard freeze has passed — two to three weeks later for anything tender — and it ripens ahead of the first fall freeze.

What hardiness zone is Globe Artichoke grown in across Montana?

Montana spans USDA hardiness zones 3a-6b (USDA ARS PHZM 2023). Globe Artichoke carries a range of zones 7-11, 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). Globe Artichoke needs 210+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Deer Lodge, the freeze-free season runs shorter than the state average, so verify your own county's window.

Is Globe Artichoke native to Montana?

No — the USDA PLANTS Database lists Globe Artichoke 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 Globe Artichoke in Montana?

Globe Artichoke prefers pH 5.5-8.3 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Montana soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.

Will Globe Artichoke actually grow on my specific land in Montana?

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

Free Report

Check your specific parcel in Montana

State-level data is a sketch. Your Growable Ground report scores globe artichoke against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Montana globe artichoke 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 globe artichoke average

Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →

Cite this dataset

Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643

Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643

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