Rosebud County, in Montana, sits in USDA hardiness zone 4b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Well-matched crops include cabbage, cranberry, turkish rocket, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Rosebud County lies within the Yellowstone Valley — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Rosebud County holds more than one microclimate.
Soils and elevations shift across Rosebud County, so your frost dates and drainage aren't the county average. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Rosebud County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Rosebud County — the short answer
Rosebud County, Montana: USDA zone 4b, about 166 days between hard freezes, across 3.2M acres.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 28
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 11
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~166
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 3.2M acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 4b is Rosebud County's average, not your lot's — a low corner or a tree line moves it. Against Rosebud County's 166-day season, see what your own ground reads.
Heat in Rosebud County
Across a year, Rosebud County accumulates about 2,120 growing degree days above 50°F, about 450 more than the middle Montana county — ahead of 50 of Montana’s 56 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Rosebud County
Across Rosebud County, the ground is predominantly Entisols, where Midway, Cabba, and Yamacall are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 7.2–7.9, slightly alkaline. Rainfall drains through hydrologic group D soils.
Soil order
Entisols
Drainage
Well drained
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Rosebud County
The USDA soil survey maps 93% of Rosebud County as well drained — but another 3% drains differently: 1% excessively drained, 1% moderately well drained.
Midway is the most extensive named soil at 9% of mapped acres, then Cabba (6%) and Yamacall (6%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Rosebud County
Each reading below is measured for Rosebud County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Rosebud County are well drained, in hydrologic group D — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Rosebud County runs about pH 7.2–7.9, on the alkaline side.
Many vegetables cope, but acid-lovers like blueberries struggle, and iron and manganese lock up above about pH 7.5 — leaves yellow between the veins even in rich soil.
Elemental sulfur and generous organic matter lower pH slowly for the beds that need it; test first so you add only what the soil actually calls for.
USDA NRCS SSURGO
Season length
MeasuredRosebud County runs about 166 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredRosebud County sits in USDA hardiness zone 4b.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Rosebud County is in
Rosebud County sits in the Northwestern Great Plains — EPA Level III, inside the wider Great Plains. One consistent ecological setting across the whole county.
What Grows in Rosebud County
We scored all 1,086 plants against Rosebud County's own USDA zone 4b and its own 166-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Montana profile.
Is it too late to plant in Rosebud County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 31; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 11 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
What gets applied to farmland in Rosebud County
USGS estimates 37,196 lb of Glyphosate on Rosebud County farmland in 2019, its largest by weight, ahead of 2,4-d (18,272 lb) and Dicamba (6,586 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Rosebud County — and how to grow with it.
We checked the federal record across Rosebud County — 827 documented sites across 6 of the 9 source types we track.
The most significant on record: 2 Superfund sites (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Rosebud County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Rosebud County
Closest first, across Rosebud County. Listing isn't leaking, and distance isn't exposure.
- 05N40E22BDAC01Nitrate · 1.9 mi
- 05N41E16CCCD02Nitrate · 2.4 mi
- BIG WALL FIELDUnderground Storage Tanks · 4.9 mi
- LEASE FACILITY STENSVAD UNITUnderground Storage Tanks · 4.9 mi
- JERRYS BIG SKY SERVICEUnderground Storage Tanks · 6.1 mi
- CRAIG NILE WELDING SHOPUnderground Storage Tanks · 6.1 mi
- AMERIGAS PROPANE LPUnderground Storage Tanks · 6.1 mi
- PIT STOP 23Underground Storage Tanks · 6.2 mi
- RESTWEL MOTELUnderground Storage Tanks · 6.2 mi
- GOOD EARTH RECYCLINGUnderground Storage Tanks · 6.2 mi
- TOWN PUMP INC FORSYTHUnderground Storage Tanks · 6.3 mi
- PRINCE INC - 777-2576Brownfields · 6.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Rosebud County's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Rosebud County.
Total Sites
827
across Rosebud County
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
across Rosebud County
Severity Distribution
across Rosebud County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Rosebud County, Nitrate runs higher than the national average — 734 sites across Rosebud County. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Rosebud County
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Rosebud County average
Your land is one point inside Rosebud County
Everything above resolves to Rosebud County as a whole — one PHZM band and one county frost record, read across 3.2M acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at county scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better county average.
Your Lot vs the Rosebud County Average
Rosebud County Average
- ●USDA Zones 4b, averaged across Rosebud County
- ●One soil character for all of Rosebud County
- ●Frost dates read at Rosebud County's scale: Apr 28 to Oct 11
YOUR Parcel
- ✓Your exact zone, not Rosebud County's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Rosebud County
Pull a site-specific report for your exact address in Rosebud County, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Rosebud County averages can't show:
We read public map data around Rosebud County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Rosebud County average
How we know this about Rosebud County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Rosebud County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Rosebud County
When does frost risk typically end in Rosebud County?
The last hard freeze (28°F) in Rosebud County typically lands around Apr 28, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about May 19.
How long is the growing season in Rosebud County?
Measured between 28°F hard freezes, Rosebud County sees about 166 frost-free days — roughly Apr 28 through Oct 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 19 to Sep 27, about 131 days.
Is the soil safe to grow vegetables in Rosebud County?
The federal record around Rosebud County is a meaningful one — 827 documented sites, mostly Nitrate entries (734), the nearest Nitrate record about 1.9 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
Everything above is measured at Rosebud County's scale — its 4b band and its 166-day season. Your yard writes its own version of Rosebud County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Montana's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Rosebud County’s own scale
8 of the readings below were taken at Rosebud County's own scale — its own ~166-day span between 28°F freezes, the 3 most extensive soil series mapped here and 827 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Rosebud County's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Rosebud County's own 28°F hard-freeze dates and its ~166-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Rosebud CountyUSDA NRCS SSURGO
- 827 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 1.9 miles outFederal environmental registers
- Rosebud County's boundary and the 3,205,204 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~166-day seasonGrowable Ground crop-matching engine
- Rosebud County sitting wholly inside the Northwestern Great PlainsUS EPA Level III Ecoregions
- Which agricultural compounds go onto Rosebud County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Montana grower plans around — written at state scale, so they stay on the state guidefrom Montana
What this page can’t tell you
- How the season shifts across Rosebud County — the ~166 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Rosebud County's 3,205,204 acreswhy one lot differs from the next →
- Which of those 827 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Rosebud Countyread your own land →