Sapphire Ridge, Montana, sits in USDA hardiness zone 4a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
On paper, cabbage, cranberry, cilantro, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Sapphire Ridge, 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 Sapphire Ridge 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 Sapphire Ridge — soil, climate, flood, and parcel records. How we handle your address.
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Sapphire Ridge — the short answer
Sapphire Ridge, Montana: USDA zone 4a, about 129 days between hard freezes, across 346 acres of town.
- USDA zone
- 4a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 19
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~129
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 346 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 4a is Sapphire Ridge's average, not your lot's — a low corner or a tree line moves it. Against Sapphire Ridge's 129-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Sapphire Ridge
Each reading below is measured for Sapphire Ridge itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSapphire Ridge runs about 129 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
MeasuredSapphire Ridge sits in USDA hardiness zone 4a.
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 Sapphire Ridge is in
Sapphire Ridge sits in the Northwestern Great Plains — EPA Level III, inside the wider Great Plains. That is read at Sapphire Ridge's own centroid rather than borrowed from Judith Basin County.
What Grows in Sapphire Ridge
Every plant below cleared Sapphire Ridge's own zone 4a and its 129-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Sapphire Ridge?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Apr 21; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 19 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 25 — long-season crops need about 90 days of runway, quick greens only 30. Short seasons reward decisiveness — quick-maturing varieties late, hardy greens under cover, and next year’s garlic in the ground before it closes.
What's on the federal record near Sapphire Ridge
Closest first, within ~10 miles of Sapphire Ridge. Listing isn't leaking, and distance isn't exposure.
- UTICA TRADING POSTUnderground Storage Tanks · 1400 ft
- C & C AUCTION BARNUnderground Storage Tanks · 1400 ft
- BLUE NUGGET BARUnderground Storage Tanks · 1400 ft
- HOBSON CAFE BLDGUnderground Storage Tanks · 1400 ft
- FRENCH AERO SPRAYING UTICAUnderground Storage Tanks · 1400 ft
- JUDITH BASIN COUNTY SHOPUnderground Storage Tanks · 1400 ft
- BASIN SERVICEUnderground Storage Tanks · 1400 ft
- 13N11E14DD 01Nitrate · 1.5 mi
- 13N11E35AB 01Nitrate · 3.1 mi
- 14N13E30BC 01Nitrate · 7.0 mi
- 14N13E30BCD 01Nitrate · 7.1 mi
- 13N13E04AADD01Nitrate · 8.8 mi
5 more sites are on the record inside the same radius. See them on the map
Measured from Sapphire Ridge'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 Sapphire Ridge.
Total Sites
25
within ~10 miles of Sapphire Ridge
Risk Level
Low
Highest-severity
1 mining site (prospects, none worked)
Sources Checked
within ~10 miles of Sapphire Ridge
Severity Distribution
within ~10 miles of Sapphire Ridge
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Sapphire Ridge, Nitrate runs higher than the national average — 16 sites within ~10 miles of Sapphire Ridge. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Sapphire Ridge
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 Sapphire Ridge average
Your land is one point inside Sapphire Ridge
Everything above resolves to Sapphire Ridge as a whole — one PHZM band and one 28°F frost record, read across 346 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 Sapphire Ridge Average
Sapphire Ridge Average
- ●USDA Zones 4a, averaged across Sapphire Ridge
- ●One soil character for all of Sapphire Ridge
- ●Frost dates read at Sapphire Ridge's scale: May 19 to Sep 25
YOUR Parcel
- ✓Your exact zone, not Sapphire Ridge's 4a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Sapphire Ridge
Pull a site-specific report for your exact address in Sapphire Ridge, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Sapphire Ridge averages can't show:
We read public map data around Sapphire Ridge — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Sapphire Ridge average
How we know this about Sapphire Ridge
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 Sapphire Ridge’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 Sapphire Ridge
When does frost risk typically end in Sapphire Ridge?
The last hard freeze (28°F) in Sapphire Ridge typically lands around May 19, 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 Jun 9.
When is the first frost in Sapphire Ridge?
The first hard freeze (28°F) in Sapphire Ridge typically arrives around Sep 25, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 11, so the watching starts about Aug 26 — about 129 days after the spring freeze cleared.
How long is the growing season in Sapphire Ridge?
Measured between 28°F hard freezes, Sapphire Ridge sees about 129 frost-free days — roughly May 19 through Sep 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 9 to Sep 11, about 94 days.
Is the soil safe to grow vegetables in Sapphire Ridge?
The federal record around Sapphire Ridge is light — 25 documented sites across the 9 federal source types we checked, mostly Nitrate entries (16), the nearest Underground Storage Tanks record about 0.3 miles out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do gardeners stretch the season in Sapphire Ridge?
With about 129 frost-free days between hard freezes, Sapphire Ridge 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 157 to 185 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 19 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Sapphire Ridge's scale — its 4a band and its 129-day season. Your yard writes its own version of Sapphire Ridge'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 Sapphire Ridge’s own scale
6 of the readings below were taken at Sapphire Ridge's own scale — its own ~129-day season between 28°F freezes, the 346 acres it covers and 25 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Sapphire Ridge's own USDA hardiness band, zones 4aUSDA PHZM 2023
- Sapphire Ridge's own 28°F hard-freeze dates, about May 19 and Sep 25 and the ~129-day span between themNOAA 1991–2020 Climate Normals
- 25 documented contamination sites on the federal record near Sapphire Ridge, the closest Underground Storage Tanks record about 0.3 miles out from the town centreFederal environmental registers
- Sapphire Ridge's boundary and the 346 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4a and a ~129-day seasonGrowable Ground crop-matching engine
- The ecoregion at Sapphire Ridge's own centroid, the Northwestern Great PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Sapphire Ridge's 346 acres read through its county's SSURGO summaryfrom Judith Basin County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Judith Basin 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 Judith Basin County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Sapphire Ridge's 346 acreswhy one lot differs from the next →
- Which side of Sapphire Ridge you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 346 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.3 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 Sapphire Ridge-wide figureread your own land →
More in Montana
Wider growing context
What grows across MontanaSapphire Ridge sits outside our named growing regions, so Montana as a whole is its closest context here.