Stephens County, in Oklahoma, sits in USDA hardiness zone 8a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
A short list that earns its place here — cabbage, fig, california poppy, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Stephens County holds more than one microclimate.
Soils and elevations shift across Stephens County, so your frost dates and drainage aren't the county average. 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 Stephens County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Stephens County — the short answer
Stephens County, Oklahoma: USDA zone 8a, about 248 days between hard freezes, across 557K acres.
- USDA zone
- 8a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 14
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 17
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~248
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 557K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 8a is Stephens County's average, not your lot's — a low corner or a tree line moves it. Against Stephens County's 248-day season, see what your own ground reads.
Heat and winter chill in Stephens County
Across a year, Stephens County accumulates about 5,021 growing degree days above 50°F, about 301 more than the middle Oklahoma county — ahead of 64 of Oklahoma’s 77 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Winter banks about 1,729 hours below 45°F, 190 fewer than the Oklahoma middle of 1,919. Chill is what tells a fruit tree its dormancy is over, and it is set by climate rather than by anything you can build.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Stephens County
Across Stephens County, the ground is predominantly Mollisols, where Stephenville, Zaneis, and Chickasha are the most extensive named soil series. The soil is generally well drained with a fine sandy loam surface. Topsoil pH runs about 5.8–6.5, slightly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
55%
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Stephens County
The USDA soil survey maps 91% of Stephens County as well drained — but another 7% drains differently: 6% moderately well drained.
Stephenville is the most extensive named soil at 24% of mapped acres, then Zaneis (14%) and Chickasha (11%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Stephens County
Each reading below is measured for Stephens County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Stephens County are well drained, in hydrologic group C — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Stephens County runs about pH 5.8–6.5, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredStephens County runs about 248 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredStephens County sits in USDA hardiness zone 8a.
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 Stephens County is in
Stephens County spans 2 EPA Level III ecoregions — Cross Timbers (70%) and Central Great Plains (30%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Stephens County
We scored all 1,086 plants against Stephens County's own USDA zone 8a and its own 248-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Oklahoma profile.
Is it too late to plant in Stephens County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Feb 14; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 14 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 17 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Stephens County
- monarch butterfly2 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Stephens County
USGS estimates 37,778 lb of 2,4-d on Stephens County farmland in 2019, its largest by weight, ahead of Glyphosate (3,307 lb) and Atrazine (2,163 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Stephens County — and how to grow with it.
We checked the federal record across Stephens County — 288 documented sites across 7 of the 9 source types we track.
The most significant on record: 2 Superfund sites (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Stephens County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Stephens County
Closest first, across Stephens County. Listing isn't leaking, and distance isn't exposure.
- Arkansas Louisiana Gas Co.Underground Storage Tanks · 0.9 mi
- SOONER AIRGAS INCToxics Release Inventory · 1.2 mi
- Jones Drilling CorporationUnderground Storage Tanks · 2.4 mi
- Cal Gas-DuncanUnderground Storage Tanks · 2.8 mi
- Water Filter PlantUnderground Storage Tanks · 3.1 mi
- Cotton Electric-Duncan Ware.Underground Storage Tanks · 3.6 mi
- Eastland GroceryUnderground Storage Tanks · 4.3 mi
- Cummins Southern Plains IncUnderground Storage Tanks · 4.3 mi
- Public Service CompanyUnderground Storage Tanks · 4.3 mi
- Midway Truck StopUnderground Storage Tanks · 4.4 mi
- Perkins Energy CompanyUnderground Storage Tanks · 4.4 mi
- Albin EnterprisesUnderground Storage Tanks · 4.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Stephens County'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 Stephens County.
Total Sites
288
across Stephens County
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
across Stephens County
Severity Distribution
across Stephens County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Stephens County, two things run higher than the national average across Stephens County — Toxics Release Inventory (24 sites) and Underground Storage Tanks (207 sites). That's not a problem with your land — it's information about it.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Stephens County
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 Stephens County average
Your land is one point inside Stephens County
Everything above resolves to Stephens County as a whole — one PHZM band and one county frost record, read across 557K 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 county 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 county average.
Your Lot vs the Stephens County Average
Stephens County Average
- ●USDA Zones 8a, averaged across Stephens County
- ●One soil character for all of Stephens County
- ●Frost dates read at Stephens County's scale: Mar 14 to Nov 17
YOUR Parcel
- ✓Your exact zone, not Stephens County's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Stephens County
Pull a site-specific report for your exact address in Stephens County, Oklahoma — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Stephens County averages can't show:
We read public map data around Stephens County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Stephens County average
How we know this about Stephens County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Stephens County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Stephens County
When does frost risk typically end in Stephens County?
The last hard freeze (28°F) in Stephens County typically lands around Mar 14, 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 Apr 4.
How long is the growing season in Stephens County?
Measured between 28°F hard freezes, Stephens County sees about 248 frost-free days — roughly Mar 14 through Nov 17, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 4 to Nov 3, about 213 days.
Is the soil safe to grow vegetables in Stephens County?
The federal record around Stephens County is a meaningful one — 288 documented sites, mostly Underground Storage Tanks entries (207), the nearest Underground Storage Tanks record about 0.9 miles 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.
Everything above is measured at Stephens County's scale — its 8a band and its 248-day season. Your yard writes its own version of Stephens County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Oklahoma's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Stephens County’s own scale
9 of the readings below were taken at Stephens County's own scale — its own ~248-day span between 28°F freezes, the 3 most extensive soil series mapped here and 288 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Stephens County's own USDA hardiness band, zones 8aUSDA PHZM 2023
- Stephens County's own 28°F hard-freeze dates and its ~248-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Stephens CountyUSDA NRCS SSURGO
- 288 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.9 miles outFederal environmental registers
- Stephens County's boundary and the 556,935 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~248-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Stephens County spans, Cross Timbers the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Stephens County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Stephens County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Oklahoma grower plans around — written at state scale, so they stay on the state guidefrom Oklahoma
What this page can’t tell you
- How the season shifts across Stephens County — the ~248 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Stephens County's 556,935 acreswhy one lot differs from the next →
- Which of those 288 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Stephens Countyread your own land →