South Hills, Montana, sits in USDA hardiness zone 5a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
On paper, cabbage, cranberry, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in South Hills, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single South Hills lot. 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 South Hills — soil, climate, flood, and parcel records. How we handle your address.
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South Hills — the short answer
South Hills, Montana: USDA zone 5a, about 145 days between hard freezes, across 4K acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~145
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 4K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 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 5a is South Hills's average, not your lot's — a low corner or a tree line moves it. Against South Hills's 145-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in South Hills
Each reading below is measured for South Hills itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSouth Hills runs about 145 days between hard freezes — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredSouth Hills sits in USDA hardiness zone 5a.
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 South Hills is in
South Hills sits in the Middle Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at South Hills's own centroid rather than borrowed from Jefferson County.
What Grows in South Hills
Every plant below cleared South Hills's own zone 5a and its 145-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in South Hills?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Apr 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 7 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 29 — long-season crops need about 90 days of runway, quick greens only 30. When the window is tight, the fall moves are quick ones — baby greens, radishes, and garlic set for next season.
What's on the federal record near South Hills
Closest first, within ~10 miles of South Hills. Listing isn't leaking, and distance isn't exposure.
- 09N03W04DBDC01Nitrate · 0.7 mi
- Maybesto & Try ClaimsMining · 1.1 mi
- Clark LeadMining · 1.3 mi
- Meadow MineMining · 1.6 mi
- BERGUM DRUGBrownfields · 1.7 mi
- ST PETERS COMMUNITY HOSPITALUnderground Storage Tanks · 1.9 mi
- ST PETERS HEALTHBrownfields · 1.9 mi
- 09N03W21BAAC01Nitrate · 2.0 mi
- MONTANA ENVIRONMENTAL LABORATORYBrownfields · 2.1 mi
- 09N03W02BCCB01Nitrate · 2.1 mi
- MT DOA HELENA GENERAL SERVICESBrownfields · 2.2 mi
- AT & T COMMUNICATIONS LAKE RADIOUnderground Storage Tanks · 2.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from South Hills'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 South Hills.
Sources Checked
within ~10 miles of South Hills
Severity Distribution
within ~10 miles of South Hills
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around South Hills, two things run higher than the national average within ~10 miles of South Hills — Mining (139 sites) and Nitrate (614 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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).
Check your specific parcel in South Hills
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 South Hills average
Your land is one point inside South Hills
Everything above resolves to South Hills as a whole — one PHZM band and one 28°F frost record, read across 4K 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 town 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 local average.
Your Lot vs the South Hills Average
South Hills Average
- ●USDA Zones 5a, averaged across South Hills
- ●One soil character for all of South Hills
- ●Frost dates read at South Hills's scale: May 7 to Sep 29
YOUR Parcel
- ✓Your exact zone, not South Hills's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in South Hills
Pull a site-specific report for your exact address in South Hills, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that South Hills averages can't show:
We read public map data around South Hills — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the South Hills average
How we know this about South Hills
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at South Hills’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about South Hills
When does frost risk typically end in South Hills?
The last hard freeze (28°F) in South Hills typically lands around May 7, 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 28.
When is the first frost in South Hills?
The first hard freeze (28°F) in South Hills typically arrives around Sep 29, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 15, so the watching starts about Aug 30 — about 145 days after the spring freeze cleared.
How long is the growing season in South Hills?
Measured between 28°F hard freezes, South Hills sees about 145 frost-free days — roughly May 7 through Sep 29, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 28 to Sep 15, about 110 days.
Is the soil safe to grow vegetables in South Hills?
The federal record around South Hills runs heavier than most — 1,106 documented sites, mostly Nitrate entries (614), the nearest Nitrate record about 0.7 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do gardeners stretch the season in South Hills?
With about 145 frost-free days between hard freezes, South Hills rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 173 to 201 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 7 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at South Hills's scale — its 5a band and its 145-day season. Your yard writes its own version of South Hills's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at South Hills’s own scale
6 of the readings below were taken at South Hills's own scale — its own ~145-day season between 28°F freezes, the 3,759 acres it covers and 1,106 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- South Hills's own USDA hardiness band, zones 5aUSDA PHZM 2023
- South Hills's own 28°F hard-freeze dates, about May 7 and Sep 29 and the ~145-day span between themNOAA 1991–2020 Climate Normals
- 1,106 documented contamination sites on the federal record near South Hills, the closest Nitrate record about 0.7 miles out from the town centreFederal environmental registers
- South Hills's boundary and the 3,759 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~145-day seasonGrowable Ground crop-matching engine
- The ecoregion at South Hills's own centroid, the Middle RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so South Hills's 3,759 acres read through its county's SSURGO summaryfrom Jefferson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Jefferson County
- The growing challenges every Montana grower plans around — written at state scale, so they stay on the state guidefrom Montana
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Jefferson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among South Hills's 3,759 acreswhy one lot differs from the next →
- Which side of South Hills you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,759 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.7 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any South Hills-wide figureread your own land →
More in Montana
Wider growing context
What grows across MontanaSouth Hills sits outside our named growing regions, so Montana as a whole is its closest context here.
Nearby growing guides