Hartville, Wyoming, sits in USDA hardiness zone 5a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
The conditions favor cabbage, cranberry, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Hartville, 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 Hartville 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 Hartville — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Hartville — the short answer
Hartville, Wyoming: USDA zone 5a, about 152 days between hard freezes, across 166 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)
- Oct 6
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~152
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 166 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 Hartville's average, not your lot's — a low corner or a tree line moves it. Against Hartville's 152-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Hartville
Each reading below is measured for Hartville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHartville runs about 152 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
MeasuredHartville 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 Hartville is in
Hartville sits in the High Plains — EPA Level III, inside the wider Great Plains. That is read at Hartville's own centroid rather than borrowed from Platte County.
What Grows in Hartville
Every plant below cleared Hartville's own zone 5a and its 152-day season. Each card opens that plant's Wyoming profile. How we score.
Is it too late to plant in Hartville?
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 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 Oct 6 — 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 Hartville
Closest first, within ~10 miles of Hartville. Listing isn't leaking, and distance isn't exposure.
- Clarence W. VannelliUnderground Storage Tanks · 75 ft
- Jehosophat ProspectMining · 450 ft
- Jehosephat ProspectMining · 500 ft
- HARTVILLE (TRONOX)Superfund · 650 ft
- John ChiamulonUnderground Storage Tanks · 1100 ft
- WDEQ SUNRISE MINE FACILITIES/BROWNFIELDS SITE IS THE FORMER YMCA BUILDINGBrownfields · 0.9 mi
- Sunrise MineMining · 1.2 mi
- Sunrise MineUnderground Storage Tanks · 1.3 mi
- GUERNSEY CAMP SITE AND MANEUVER AREASuperfund · 3.5 mi
- Green Mtn BoyMining · 3.6 mi
- WYOMING ARMY NATIONAL GUARD-WYARNG- CAMP GUERNSEY, GUERNSEY, WYOMINGBrownfields · 4.0 mi
- BNSF - GuernseyUnderground Storage Tanks · 4.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Hartville'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 Hartville.
Total Sites
46
within ~10 miles of Hartville
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Hartville
Severity Distribution
within ~10 miles of Hartville
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Hartville, Mining runs higher than the national average — 8 sites within ~10 miles of Hartville. That's not a problem with your land — it's information about it.
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 Hartville
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 Hartville average
Your land is one point inside Hartville
Everything above resolves to Hartville as a whole — one PHZM band and one 28°F frost record, read across 166 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 Hartville Average
Hartville Average
- ●USDA Zones 5a, averaged across Hartville
- ●One soil character for all of Hartville
- ●Frost dates read at Hartville's scale: May 7 to Oct 6
YOUR Parcel
- ✓Your exact zone, not Hartville's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Hartville
Pull a site-specific report for your exact address in Hartville, Wyoming — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Hartville averages can't show:
We read public map data around Hartville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Hartville average
How we know this about Hartville
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 Hartville’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 Hartville
When does frost risk typically end in Hartville?
The last hard freeze (28°F) in Hartville 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 Hartville?
The first hard freeze (28°F) in Hartville typically arrives around Oct 6, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 22, so the watching starts about Sep 6 — about 152 days after the spring freeze cleared.
How long is the growing season in Hartville?
Measured between 28°F hard freezes, Hartville sees about 152 frost-free days — roughly May 7 through Oct 6, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 28 to Sep 22, about 117 days.
Is the soil safe to grow vegetables in Hartville?
The federal record around Hartville is a meaningful one — 46 documented sites, mostly Underground Storage Tanks entries (16), the nearest Underground Storage Tanks record under a tenth of a mile out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Hartville?
From about Sep 6 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 6 (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 6. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Hartville's scale — its 5a band and its 152-day season. Your yard writes its own version of Hartville'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 Hartville’s own scale
6 of the readings below were taken at Hartville's own scale — its own ~152-day season between 28°F freezes, the 166 acres it covers and 46 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Hartville's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Hartville's own 28°F hard-freeze dates, about May 7 and Oct 6 and the ~152-day span between themNOAA 1991–2020 Climate Normals
- 46 documented contamination sites on the federal record near Hartville, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Hartville's boundary and the 166 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~152-day seasonGrowable Ground crop-matching engine
- The ecoregion at Hartville's own centroid, the High PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Hartville's 166 acres read through its county's SSURGO summaryfrom Platte County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Platte County
- The growing challenges every Wyoming grower plans around — written at state scale, so they stay on the state guidefrom Wyoming
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Platte County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Hartville's 166 acreswhy one lot differs from the next →
- Which side of Hartville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 166 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 Hartville-wide figureread your own land →
More in Wyoming
Growing region
Nearby growing guides