Unlikely — Zone Mismatch
bahiagrass (zones 7-10) does not overlap with Montana's zone range (3a-6b). Growing outdoors is unlikely without significant protection.
2 zones short — what would close it
Bahiagrass 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 bahiagrass 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 7-10 (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 bahiagrass 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
Zone Comparison
Bahiagrass Needs
- USDA Zones: 7-10
- Frost-Free Days: 150+
- Sun: Part Sun
- Mature size: 1.5 ft tall
- Drought tolerance: High
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 7-10)
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 Bahiagrass 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
Bahiagrass 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
Bahiagrass is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Montana's dates above are the whole calendar for it. That makes the last-freeze date the binding constraint, and a warmer pocket of your own yard is worth more to this crop than it is to a transplanted one.
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 bahiagrass 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
Bahiagrass wants 150+ frost-free days; a typical Montana site sees ~151 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves a tight window — use transplants and pick early-maturing cultivars.
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
Bahiagrass tolerates a wide pH range (pH 4.3-8.3) — 4 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 5 and 6.2 — 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. Bahiagrass needs about 59 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 bahiagrass 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.
Bahiagrass in Montana — Quick Answer
- Verdict: Unlikely — Zone Mismatch
- Plant Zones: 7-10 (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)
What Else to Consider for Bahiagrass 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 bahiagrass here specifically
Bahiagrass prefers pH 4.3–8.3 and room to root deep; across much of Montana, restrictive group-D subsoil (SSURGO) blocks that depth.
Build bahiagrass a deep raised bed of loose soil to bypass the dense subsoil entirely. How to handle it →
What to actually do about these — and the constraints that apply to every Montana grower, not just bahiagrass — 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 bahiagrass to your county's window, not the statewide date.
Bahiagrass needs about 150 days of frost-free season to complete its cycle. 31 of Montana’s 56 counties give it that outright. The tightest that does is Carter County at 150 frost-free days — 0 to spare. Below that line you are transplanting or extending the season, not direct-sowing.
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, leaving bahiagrass about 1 days of slack on a typical parcel — room for a second sowing where the season runs long.
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"). Bahiagrass's 150-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Montana Cooperative Extension
For Montana-specific cultivar recommendations, planting calendars, and pest pressure for bahiagrass, the canonical source is Montana State University Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Bahiagrass native to Montana?
No — the USDA PLANTS Database lists Bahiagrass 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 Bahiagrass in Montana
When can I plant Bahiagrass 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). Bahiagrass 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.
What hardiness zone is Bahiagrass grown in across Montana?
Montana spans USDA hardiness zones 3a-6b (USDA ARS PHZM 2023). Bahiagrass carries a range of zones 7-10, 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). Bahiagrass needs 150+ 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 Bahiagrass native to Montana?
No — the USDA PLANTS Database lists Bahiagrass 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 Bahiagrass in Montana?
Bahiagrass tolerates pH 4.3-8.3 and well (dry spells) drainage (FAO ECOCROP). That is a 4-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 Bahiagrass actually grow on my specific land in Montana?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores bahiagrass 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 bahiagrass against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Montana bahiagrass 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 bahiagrass average
Explore More
Growing guides for bahiagrass
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
Last updated: