Karnes County, in Texas, sits in USDA hardiness zone 9a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Well-matched crops include artichoke, fig, california poppy, and cabbage, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Karnes County holds more than one microclimate.
Soils and elevations shift across Karnes 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 Karnes County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Karnes County — the short answer
Karnes County, Texas: USDA zone 9a, about 307 days between hard freezes, across 479K acres.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 5
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Dec 9
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~307
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 479K 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 9a is Karnes County's average, not your lot's — a low corner or a tree line moves it. Against Karnes County's 307-day season, see what your own ground reads.
Heat and winter chill in Karnes County
Across a year, Karnes County accumulates about 7,602 growing degree days above 50°F, about 1,778 more than the middle Texas county — ahead of 224 of Texas’s 254 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 264 hours below 45°F, 831 fewer than the Texas middle of 1,095. 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 Karnes County
Across Karnes County, the ground is predominantly Mollisols, where Coy, Weesatche, and Pernitas are the most extensive named soil series. The soil is generally well drained with a fine sandy loam surface. Topsoil pH runs about 7.0–7.9, slightly alkaline. Rainfall drains through hydrologic group D soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
62%
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Karnes County
The USDA soil survey maps 85% of Karnes County as well drained — but another 15% drains differently: 14% moderately well drained.
Coy is the most extensive named soil at 13% of mapped acres, then Weesatche (12%) and Pernitas (10%).
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 Karnes County
Each reading below is measured for Karnes 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 Karnes County are well drained, in hydrologic group D — 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 Karnes County runs about pH 7.0–7.9, on the alkaline side.
Many vegetables cope, but acid-lovers like blueberries struggle, and iron and manganese lock up above about pH 7.5 — leaves yellow between the veins even in rich soil.
Elemental sulfur and generous organic matter lower pH slowly for the beds that need it; test first so you add only what the soil actually calls for.
USDA NRCS SSURGO
Season length
MeasuredKarnes County runs about 307 days between hard freezes — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredKarnes County sits in USDA hardiness zone 9a.
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 Karnes County is in
Karnes County sits in the East Central Texas Plains — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Karnes County
We scored all 1,086 plants against Karnes County's own USDA zone 9a and its own 307-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 Texas profile.
Is it too late to plant in Karnes County?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Jan 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 9 — long-season crops need about 90 days of runway, quick greens only 30. With almost year-round growing weather, timing is about heat and rainfall more than frost — some bench is always in play.
Documented around Karnes County
- monarch butterfly3 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Karnes County
USGS estimates 47,451 lb of Glyphosate on Karnes County farmland in 2019, its largest by weight, ahead of 2,4-d (21,524 lb) and Atrazine (20,086 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 Karnes County — and how to grow with it.
We checked the federal record across Karnes County — 134 documented sites across 7 of the 9 source types we track.
The most significant on record: 1 Superfund site (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 Karnes 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 Karnes County
Closest first, across Karnes County. Listing isn't leaking, and distance isn't exposure.
- KOUNTRY KORNERUnderground Storage Tanks · 2600 ft
- PALACE CAFEUnderground Storage Tanks · 2600 ft
- FILLIN STATIONUnderground Storage Tanks · 2600 ft
- KENEDY PUBLIC SCHOOLUnderground Storage Tanks · 2600 ft
- LAURA BURNEYUnderground Storage Tanks · 2600 ft
- CONQUISTA PROJECTUnderground Storage Tanks · 2600 ft
- CHARCO COMPRESSOR STATIONUnderground Storage Tanks · 2600 ft
- REAGAN TEXACOUnderground Storage Tanks · 2600 ft
- FALLS CITY TEXACOUnderground Storage Tanks · 2600 ft
- FABIAN STURMS EXXONUnderground Storage Tanks · 2600 ft
- ROBBINS GROCERYUnderground Storage Tanks · 2600 ft
- PAWALEKS STOREUnderground Storage Tanks · 2600 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Karnes 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 Karnes County.
Total Sites
134
across Karnes County
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
across Karnes County
Severity Distribution
across Karnes County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Karnes County, two things run higher than the national average across Karnes County — Toxics Release Inventory (9 sites) and Underground Storage Tanks (87 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around 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 Karnes 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 Karnes County average
Your land is one point inside Karnes County
Everything above resolves to Karnes County as a whole — one PHZM band and one county frost record, read across 479K 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 Karnes County Average
Karnes County Average
- ●USDA Zones 9a, averaged across Karnes County
- ●One soil character for all of Karnes County
- ●Frost dates read at Karnes County's scale: Feb 5 to Dec 9
YOUR Parcel
- ✓Your exact zone, not Karnes County's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Karnes County
Pull a site-specific report for your exact address in Karnes County, Texas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Karnes County averages can't show:
We read public map data around Karnes County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Karnes County average
How we know this about Karnes 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 Karnes County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Karnes County
When does frost risk typically end in Karnes County?
The last hard freeze (28°F) in Karnes County typically lands around Feb 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 Feb 26.
How long is the growing season in Karnes County?
Measured between 28°F hard freezes, Karnes County sees about 307 frost-free days — roughly Feb 5 through Dec 9, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 26 to Nov 25, about 272 days.
Is the soil safe to grow vegetables in Karnes County?
The federal record around Karnes County is a meaningful one — 134 documented sites, mostly Underground Storage Tanks entries (87), the nearest Underground Storage Tanks record about 0.5 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 Karnes County's scale — its 9a band and its 307-day season. Your yard writes its own version of Karnes 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 Texas's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Karnes County’s own scale
9 of the readings below were taken at Karnes County's own scale — its own ~307-day span between 28°F freezes, the 3 most extensive soil series mapped here and 134 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Karnes County's own USDA hardiness band, zones 9aUSDA PHZM 2023
- Karnes County's own 28°F hard-freeze dates and its ~307-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Karnes CountyUSDA NRCS SSURGO
- 134 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.5 miles outFederal environmental registers
- Karnes County's boundary and the 478,561 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~307-day seasonGrowable Ground crop-matching engine
- Karnes County sitting wholly inside the East Central Texas PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Karnes County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Karnes County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Texas grower plans around — written at state scale, so they stay on the state guidefrom Texas
What this page can’t tell you
- How the season shifts across Karnes County — the ~307 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 Karnes County's 478,561 acreswhy one lot differs from the next →
- Which of those 134 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 Karnes Countyread your own land →