Stillwater, Minnesota, sits in USDA hardiness zone 5a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Growers here do well with cabbage, cranberry, lavender, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Stillwater, 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 Stillwater 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 Stillwater — soil, climate, flood, and parcel records. How we handle your address.
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Stillwater — the short answer
Stillwater, Minnesota: USDA zone 5a, about 189 days between hard freezes, across 5K acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 23
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~189
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 5K 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 Stillwater's average, not your lot's — a low corner or a tree line moves it. Against Stillwater's 189-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Stillwater
Each reading below is measured for Stillwater itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredStillwater runs about 189 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
MeasuredStillwater 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 Stillwater is in
Stillwater sits in the North Central Hardwood Forests — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Stillwater's own centroid rather than borrowed from Washington County.
What Grows in Stillwater
Every plant below cleared Stillwater's own zone 5a and its 189-day season. Each card opens that plant's Minnesota profile. How we score.
Is it too late to plant in Stillwater?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 20; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 17 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 23 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Stillwater
Closest first, within ~10 miles of Stillwater. Listing isn't leaking, and distance isn't exposure.
- PLASTIC PALACE BODY SHOP DBABrownfields · 2100 ft
- W353 030N20W29DDA 01 0000208786Nitrate · 2400 ft
- STILLWATER COLLISION & RESTORATION INCBrownfields · 0.5 mi
- ISD 834 LILY LAKE ELEMENTARYBrownfields · 0.6 mi
- STILLWATER TRAINING AND COMMUNITY CENTERBrownfields · 0.6 mi
- Neighbor StopUnderground Storage Tanks · 0.6 mi
- GOOD SAMARITAN STILLWATERBrownfields · 0.6 mi
- FOOD N FUEL C6Brownfields · 0.6 mi
- FISCHERS FURNITURE RESTORATIONBrownfields · 0.7 mi
- POLARIS PHARMACY (LTCF-HHW) ESTATES AT GREELEYBrownfields · 0.7 mi
- Oasis Market #526Underground Storage Tanks · 0.8 mi
- OAK GLEN COUNTRY CLUBBrownfields · 0.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Stillwater'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 Stillwater.
Sources Checked
within ~10 miles of Stillwater
Severity Distribution
within ~10 miles of Stillwater
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Stillwater, Brownfields runs higher than the national average — 970 sites within ~10 miles of Stillwater. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in Stillwater
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 Stillwater average
Your land is one point inside Stillwater
Everything above resolves to Stillwater as a whole — one PHZM band and one 28°F frost record, read across 5K 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 Stillwater Average
Stillwater Average
- ●USDA Zones 5a, averaged across Stillwater
- ●One soil character for all of Stillwater
- ●Frost dates read at Stillwater's scale: Apr 17 to Oct 23
YOUR Parcel
- ✓Your exact zone, not Stillwater's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Stillwater
Pull a site-specific report for your exact address in Stillwater, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Stillwater averages can't show:
We read public map data around Stillwater — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Stillwater average
How we know this about Stillwater
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 Stillwater’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 Stillwater
When does frost risk typically end in Stillwater?
The last hard freeze (28°F) in Stillwater typically lands around Apr 17, 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 8.
When is the first frost in Stillwater?
The first hard freeze (28°F) in Stillwater typically arrives around Oct 23, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 9, so the watching starts about Sep 23 — about 189 days after the spring freeze cleared.
How long is the growing season in Stillwater?
Measured between 28°F hard freezes, Stillwater sees about 189 frost-free days — roughly Apr 17 through Oct 23, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 8 to Oct 9, about 154 days.
Is the soil safe to grow vegetables in Stillwater?
The federal record around Stillwater runs heavier than most — 1,718 documented sites, mostly Brownfields entries (970), the nearest Brownfields record about 0.4 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 Stillwater?
From about Sep 23 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 23 (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 23. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Stillwater's scale — its 5a band and its 189-day season. Your yard writes its own version of Stillwater'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 Stillwater’s own scale
6 of the readings below were taken at Stillwater's own scale — its own ~189-day season between 28°F freezes, the 5,151 acres it covers and 1,718 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Stillwater's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Stillwater's own 28°F hard-freeze dates, about Apr 17 and Oct 23 and the ~189-day span between themNOAA 1991–2020 Climate Normals
- 1,718 documented contamination sites on the federal record near Stillwater, the closest Brownfields record about 0.4 miles out from the town centreFederal environmental registers
- Stillwater's boundary and the 5,151 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~189-day seasonGrowable Ground crop-matching engine
- The ecoregion at Stillwater's own centroid, the North Central Hardwood ForestsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Stillwater's 5,151 acres read through its county's SSURGO summaryfrom Washington County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Washington County
- The growing challenges every Minnesota grower plans around — written at state scale, so they stay on the state guidefrom Minnesota
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Washington County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Stillwater's 5,151 acreswhy one lot differs from the next →
- Which side of Stillwater you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 5,151 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.4 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 Stillwater-wide figureread your own land →
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