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 under glass — a greenhouse is the only lift this wide the engine models.
A 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 Sprint 20B effective_zone_modifier (+2 zones) via api/fast_sections.py Unlock Engine v2.
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.
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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)
Preferred Soil pH
Plant data: USDA PLANTS Database / Growable Ground plant catalog. 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 — its listed minimum temperature is 41°F (USDA PLANTS Database) — 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.
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 150 days to maturity (USDA PLANTS Database), the fit is tight: Montana's dependable window runs 138 days. Starting seeds indoors and transplanting at the front of the window banks the difference.
Timing tuned to sub-state frost dates — Deer Lodge County, not the statewide average.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: USDA PLANTS Database. 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 and drainage requirements from USDA PLANTS Database. Montana soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Globe Artichoke in Montana — Quick Answer
- Verdict: Unlikely — Zone Mismatch
- Plant Zones: 7-11 (USDA PLANTS Database)
- State Zones: 3a-6b (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about May 2 - May 13 to Sep 28 - Oct 7 (NOAA Regional Climate Centers ACIS, 1991-2020)
- Days to Maturity: 150 days
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 takes ~150 days and rates to zones 7–11; against Montana's ~150 frost-free days, timing is everything.
Buy globe artichoke weeks with an early indoor sowing and season-extending covers. 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 listed minimum temperature is 41°F (USDA PLANTS Database) — 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?
It's close: Globe Artichoke needs 150 days to mature (USDA PLANTS Database) against Montana's 138-day dependable window (NOAA Regional Climate Centers ACIS, 1991-2020). Start seeds indoors and transplant once the last hard freeze has passed to bank the missing days.
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.
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:
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
Explore More
Growing guides for globe artichoke
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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