Olney, Montana, sits in USDA hardiness zone 4b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
These conditions suit zucchini, cranberry, cilantro, and okra — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Olney, 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 Olney 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 Olney — soil, climate, flood, and parcel records. How we handle your address.
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Olney — the short answer
Olney, Montana: USDA zone 4b, about 103 days between hard freezes, across 851 acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~103
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 851 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 4b is Olney's average, not your lot's — a low corner or a tree line moves it. Against Olney's 103-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Olney
Each reading below is measured for Olney itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredOlney runs about 103 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
MeasuredOlney 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 Olney is in
Olney sits in the Northern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Olney's own centroid, and it is not what its county reads: Flathead County is mostly Canadian Rockies. The wider page above you is answering a different question about different ground.
What Grows in Olney
Every plant below cleared Olney's own zone 4b and its 103-day season. Each card opens that plant's Montana profile. How we score.
Is it too late to plant in Olney?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Apr 27; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 25 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 5 — 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 Olney
Closest first, within ~10 miles of Olney. Listing isn't leaking, and distance isn't exposure.
- OLNEY STOREUnderground Storage Tanks · 1300 ft
- 32N23W17BB 01Nitrate · 1800 ft
- MT DNRC WHITEFISHUnderground Storage Tanks · 1900 ft
- 32N23W07AC 01Nitrate · 2600 ft
- GLACIER GOLD LLCUnderground Storage Tanks · 0.5 mi
- 33N23W32DD 01Nitrate · 2.0 mi
- SAFEWAY 2106Brownfields · 2.7 mi
- MDOT OLNEYUnderground Storage Tanks · 3.3 mi
- POTTERS FIELD RANCHUnderground Storage Tanks · 3.4 mi
- DEPRATU FORDBrownfields · 3.6 mi
- Wort ProspectMining · 7.1 mi
- FLATHEAD COUNTY WATER AND SEWERPFAS · 8.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Olney'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 Olney.
Sources Checked
within ~10 miles of Olney
Severity Distribution
within ~10 miles of Olney
Highest-Severity Sites
Know Before You Grow
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Mine waste leaches heavy metals. Test for lead, arsenic and cadmium before growing food here.
Check your specific parcel in Olney
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 Olney average
Your land is one point inside Olney
Everything above resolves to Olney as a whole — one PHZM band and one 28°F frost record, read across 851 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 Olney Average
Olney Average
- ●USDA Zones 4b, averaged across Olney
- ●One soil character for all of Olney
- ●Frost dates read at Olney's scale: May 25 to Sep 5
YOUR Parcel
- ✓Your exact zone, not Olney's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Olney
Pull a site-specific report for your exact address in Olney, Montana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Olney averages can't show:
We read public map data around Olney — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Olney average
How we know this about Olney
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 Olney’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 Olney
When does frost risk typically end in Olney?
The last hard freeze (28°F) in Olney typically lands around May 25, 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 15.
When is the first frost in Olney?
The first hard freeze (28°F) in Olney typically arrives around Sep 5, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Aug 22, so the watching starts about Aug 6 — about 103 days after the spring freeze cleared.
How long is the growing season in Olney?
Measured between 28°F hard freezes, Olney sees about 103 frost-free days — roughly May 25 through Sep 5, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 15 to Aug 22, about 68 days.
Is the soil safe to grow vegetables in Olney?
The federal record around Olney shows 22 documented sites, mostly Nitrate entries (8), the nearest Underground Storage Tanks record about 0.2 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do gardeners stretch the season in Olney?
With about 103 frost-free days between hard freezes, Olney 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 131 to 159 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 25 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Olney's scale — its 4b band and its 103-day season. Your yard writes its own version of Olney'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 Olney’s own scale
6 of the readings below were taken at Olney's own scale — its own ~103-day season between 28°F freezes, the 851 acres it covers and 22 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Olney's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Olney's own 28°F hard-freeze dates, about May 25 and Sep 5 and the ~103-day span between themNOAA 1991–2020 Climate Normals
- 22 documented contamination sites on the federal record near Olney, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Olney's boundary and the 851 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~103-day seasonGrowable Ground crop-matching engine
- Olney sits in the Northern Rockies — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Olney's 851 acres read through its county's SSURGO summaryfrom Flathead County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Flathead 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 Flathead County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Olney's 851 acreswhy one lot differs from the next →
- Which side of Olney you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 851 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 Olney-wide figureread your own land →
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