Prairie City, Oregon, sits in USDA hardiness zone 6b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
The conditions favor cabbage, blackberry, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Prairie City, 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 Prairie City 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 Prairie City — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Prairie City — the short answer
Prairie City, Oregon: USDA zone 6b, about 151 days between hard freezes, across 635 acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 3
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~151
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 635 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 6b is Prairie City's average, not your lot's — a low corner or a tree line moves it. Against Prairie City's 151-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Prairie City
Each reading below is measured for Prairie City itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredPrairie City runs about 151 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
MeasuredPrairie City sits in USDA hardiness zone 6b.
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 Prairie City is in
Prairie City sits in the Blue Mountains — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Prairie City's own centroid rather than borrowed from Grant County.
What Grows in Prairie City
Every plant below cleared Prairie City's own zone 6b and its 151-day season. Each card opens that plant's Oregon profile. How we score.
Is it too late to plant in Prairie City?
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 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 3 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What's on the federal record near Prairie City
Closest first, within ~10 miles of Prairie City. Listing isn't leaking, and distance isn't exposure.
- PRAIRIE CITY TEXACOUnderground Storage Tanks · 650 ft
- VOIGT, KELLY D & BARBARA JUnderground Storage Tanks · 700 ft
- MT VIEW MINI MARTUnderground Storage Tanks · 800 ft
- OXBOW RANCHESUnderground Storage Tanks · 850 ft
- PRAIRIE WOOD PRODUCTSUnderground Storage Tanks · 850 ft
- BLUE MT RANCHERS SUPPLY INCUnderground Storage Tanks · 1000 ft
- USDA FS PRAIRIE CITY ROAD SERVICEUnderground Storage Tanks · 1100 ft
- GRANT COUNTY SCHOOL DISTRICT #4Underground Storage Tanks · 1800 ft
- PRAIRIE WOOD PRODUCTS AND CO-GEN FACILITYToxics Release Inventory · 0.6 mi
- Last Chance GroupMining · 3.5 mi
- Unnamed Uranium OccurrenceMining · 4.4 mi
- Uranium OccurrenceMining · 4.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Prairie City'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 Prairie City.
Total Sites
124
within ~10 miles of Prairie City
Risk Level
High
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Prairie City
Severity Distribution
within ~10 miles of Prairie City
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Prairie City, Mining runs higher than the national average — 114 sites within ~10 miles of Prairie City. 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.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Prairie City
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 Prairie City average
Your land is one point inside Prairie City
Everything above resolves to Prairie City as a whole — one PHZM band and one 28°F frost record, read across 635 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 city 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 Prairie City Average
Prairie City Average
- ●USDA Zones 6b, averaged across Prairie City
- ●One soil character for all of Prairie City
- ●Frost dates read at Prairie City's scale: May 5 to Oct 3
YOUR Parcel
- ✓Your exact zone, not Prairie City's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Prairie City
Pull a site-specific report for your exact address in Prairie City, Oregon — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Prairie City averages can't show:
We read public map data around Prairie City — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Prairie City average
How we know this about Prairie City
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Prairie City’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 city grain anywhere on this page — there is no city-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 Prairie City
When does frost risk typically end in Prairie City?
The last hard freeze (28°F) in Prairie City typically lands around May 5, 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 26.
When is the first frost in Prairie City?
The first hard freeze (28°F) in Prairie City typically arrives around Oct 3, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 19, so the watching starts about Sep 3 — about 151 days after the spring freeze cleared.
How long is the growing season in Prairie City?
Measured between 28°F hard freezes, Prairie City sees about 151 frost-free days — roughly May 5 through Oct 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 26 to Sep 19, about 116 days.
Is the soil safe to grow vegetables in Prairie City?
The federal record around Prairie City runs heavier than most — 124 documented sites, mostly Mining entries (114), the nearest Underground Storage Tanks record about 0.1 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 I protect my plants from frost in Prairie City?
From about Sep 3 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Oct 3 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Oct 3. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Prairie City's scale — its 6b band and its 151-day season. Your yard writes its own version of Prairie City'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 Prairie City’s own scale
6 of the readings below were taken at Prairie City's own scale — its own ~151-day season between 28°F freezes, the 635 acres it covers and 124 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Prairie City's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Prairie City's own 28°F hard-freeze dates, about May 5 and Oct 3 and the ~151-day span between themNOAA 1991–2020 Climate Normals
- 124 documented contamination sites on the federal record near Prairie City, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Prairie City's boundary and the 635 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~151-day seasonGrowable Ground crop-matching engine
- The ecoregion at Prairie City's own centroid, the Blue MountainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Prairie City's 635 acres read through its county's SSURGO summaryfrom Grant County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Grant County
- The growing challenges every Oregon grower plans around — written at state scale, so they stay on the state guidefrom Oregon
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Grant County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Prairie City's 635 acreswhy one lot differs from the next →
- Which side of Prairie City you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 635 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 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 Prairie City-wide figureread your own land →
More in Oregon
Growing region
Nearby growing guides