Carter County, in Oklahoma, sits in USDA hardiness zone 8a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
On paper, cabbage, fig, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Carter County holds more than one microclimate.
Soils and elevations shift across Carter 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 Carter County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Carter County — the short answer
Carter County, Oklahoma: USDA zone 8a, about 253 days between hard freezes, across 526K acres.
- USDA zone
- 8a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 11
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 19
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~253
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 526K 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 Carter County's average, not your lot's — a low corner or a tree line moves it. Against Carter County's 253-day season, see what your own ground reads.
Heat and winter chill in Carter County
Across a year, Carter County accumulates about 5,174 growing degree days above 50°F, about 454 more than the middle Oklahoma county — ahead of 68 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 1,593 hours below 45°F, 326 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 Carter County
Across Carter County, the ground is predominantly Alfisols, where Weatherford, Windthorst, and Konsil are the most extensive named soil series. The soil is generally well drained with a fine sandy loam surface. Topsoil pH runs about 6.2–7.0, neutral. Rainfall drains through hydrologic group B soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
40%
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Carter County
The USDA soil survey maps 71% of Carter County as well drained — but another 28% drains differently: 27% moderately well drained, 1% somewhat poorly drained.
Weatherford is the most extensive named soil at 19% of mapped acres, then Windthorst (18%) and Konsil (12%).
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 Carter County
Each reading below is measured for Carter 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 Carter County are well drained, in hydrologic group B — 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 Carter County runs about pH 6.2–7.0, 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
MeasuredCarter County runs about 253 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
MeasuredCarter 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 Carter County is in
Carter County sits in the Cross Timbers — EPA Level III, inside the wider Great Plains. One consistent ecological setting across the whole county.
What Grows in Carter County
We scored all 1,086 plants against Carter County's own USDA zone 8a and its own 253-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 Carter County?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Feb 11; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 19 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Carter County
- monarch butterfly3 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Carter County
USGS estimates 30,051 lb of 2,4-d on Carter County farmland in 2019, its largest by weight, ahead of Glyphosate (6,652 lb) and Chlorpyrifos (5,379 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 Carter County — and how to grow with it.
We checked the federal record across Carter County — 410 documented sites across 6 of the 9 source types we track.
The most significant on record: 1 Superfund site. 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 Carter 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 Carter County
Closest first, across Carter County. Listing isn't leaking, and distance isn't exposure.
- J.S. Drake LeaseUnderground Storage Tanks · 1.6 mi
- WASSON TERMINALBrownfields · 4.7 mi
- Grove Mart GroUnderground Storage Tanks · 5.4 mi
- PUNNEO'S SERVICEToxics Release Inventory · 5.4 mi
- S & J Food MartUnderground Storage Tanks · 5.4 mi
- Chickasaw Telephone Co.Underground Storage Tanks · 5.5 mi
- Carter County Dist #3Underground Storage Tanks · 5.5 mi
- Leonard RobinsonUnderground Storage Tanks · 5.6 mi
- Former Unregistered FacilityUnderground Storage Tanks · 5.6 mi
- Holt's Gro.Underground Storage Tanks · 5.6 mi
- Harry's Food MartUnderground Storage Tanks · 5.6 mi
- Ray SatterwhiteUnderground Storage Tanks · 5.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Carter 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 Carter County.
Sources Checked
across Carter County
Severity Distribution
across Carter County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Carter County, Underground Storage Tanks runs higher than the national average — 318 sites across Carter County. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Carter 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 Carter County average
Your land is one point inside Carter County
Everything above resolves to Carter County as a whole — one PHZM band and one county frost record, read across 526K 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 Carter County Average
Carter County Average
- ●USDA Zones 8a, averaged across Carter County
- ●One soil character for all of Carter County
- ●Frost dates read at Carter County's scale: Mar 11 to Nov 19
YOUR Parcel
- ✓Your exact zone, not Carter County's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Carter County
Pull a site-specific report for your exact address in Carter County, Oklahoma — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Carter County averages can't show:
We read public map data around Carter County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Carter County average
How we know this about Carter 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 Carter County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Carter County
When does frost risk typically end in Carter County?
The last hard freeze (28°F) in Carter County typically lands around Mar 11, 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 1.
How long is the growing season in Carter County?
Measured between 28°F hard freezes, Carter County sees about 253 frost-free days — roughly Mar 11 through Nov 19, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 1 to Nov 5, about 218 days.
Is the soil safe to grow vegetables in Carter County?
The federal record around Carter County is a meaningful one — 410 documented sites, mostly Underground Storage Tanks entries (318), the nearest Underground Storage Tanks record about 1.6 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 Carter County's scale — its 8a band and its 253-day season. Your yard writes its own version of Carter 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 Carter County’s own scale
9 of the readings below were taken at Carter County's own scale — its own ~253-day span between 28°F freezes, the 3 most extensive soil series mapped here and 410 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Carter County's own USDA hardiness band, zones 8aUSDA PHZM 2023
- Carter County's own 28°F hard-freeze dates and its ~253-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Carter CountyUSDA NRCS SSURGO
- 410 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 1.6 miles outFederal environmental registers
- Carter County's boundary and the 526,272 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~253-day seasonGrowable Ground crop-matching engine
- Carter County sitting wholly inside the Cross TimbersUS EPA Level III Ecoregions
- Open occurrence records documented in Carter County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Carter 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 Carter County — the ~253 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 Carter County's 526,272 acreswhy one lot differs from the next →
- Which of those 410 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 Carter Countyread your own land →