McMullen County, in Texas, sits in USDA hardiness zone 9a — a zone band wide enough that plant choice, not possibility, is the interesting question.
These conditions suit artichoke, fig, california poppy, and cabbage — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
McMullen County holds more than one microclimate.
Soils and elevations shift across McMullen 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 McMullen County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
McMullen County — the short answer
McMullen County, Texas: USDA zone 9a, about 311 days between hard freezes, across 729K acres.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 31
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Dec 8
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~311
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 729K 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 McMullen County's average, not your lot's — a low corner or a tree line moves it. Against McMullen County's 311-day season, see what your own ground reads.
Heat and winter chill in McMullen County
Across a year, McMullen County accumulates about 7,869 growing degree days above 50°F, about 2,045 more than the middle Texas county — ahead of 235 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 291 hours below 45°F, 804 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 McMullen County
Across McMullen County, the ground is predominantly Mollisols, where Cochina, Houla, and Montell are the most extensive named soil series. The soil is generally well drained with a clay surface. Topsoil pH runs about 7.5–7.9, slightly alkaline. Rainfall drains through hydrologic group D soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
0%
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across McMullen County
The USDA soil survey maps 60% of McMullen County as well drained — but another 25% drains differently: 25% moderately well drained.
Cochina is the most extensive named soil at 10% of mapped acres, then Houla (9%) and Montell (6%).
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 McMullen County
Each reading below is measured for McMullen 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 McMullen 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 McMullen County runs about pH 7.5–7.9, 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
MeasuredMcMullen County runs about 311 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
MeasuredMcMullen 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 McMullen County is in
McMullen County sits in the Southern Texas Plains — EPA Level III, inside the wider Great Plains. One consistent ecological setting across the whole county.
What Grows in McMullen County
We scored all 1,086 plants against McMullen County's own USDA zone 9a and its own 311-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 McMullen 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 Jan 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jan 31 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 8 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.
Documented around McMullen County
- monarch butterfly1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in McMullen County
USGS estimates 3,244 lb of Glyphosate on McMullen County farmland in 2019, its largest by weight, ahead of 2,4-d (2,168 lb) and Atrazine (970 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 McMullen County — and how to grow with it.
We checked the federal record across McMullen County — 121 documented sites across 4 of the 9 source types we track.
The most significant on record: 3 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
The federal record across McMullen County is a modest one — a typical footprint for a growing area. Nothing here calls for alarm; it's worth knowing which recorded sites sit closest to where you grow, and each one on the map carries its type and location. If one turns out to be a near neighbor, a one-time soil test settles the question.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near McMullen County
Closest first, across McMullen County. Listing isn't leaking, and distance isn't exposure.
- AWP OLMOS FIELD OFFICEUnderground Storage Tanks · 2.5 mi
- TGPL STATIONUnderground Storage Tanks · 2.5 mi
- WHEELERS MERCANTILEUnderground Storage Tanks · 2.5 mi
- TILDEN EXXONUnderground Storage Tanks · 2.5 mi
- AMERICAN EXPLORATIONUnderground Storage Tanks · 2.5 mi
- JOE VERASTEGUIUnderground Storage Tanks · 2.5 mi
- DICKINSON GARAGEUnderground Storage Tanks · 2.5 mi
- SU-78-36-902Nitrate · 3.1 mi
- SU-78-44-501Nitrate · 3.6 mi
- TRANS-JEFF CHEMICAL COToxics Release Inventory · 3.7 mi
- SU-78-44-402Nitrate · 4.9 mi
- SU-78-36-204Nitrate · 5.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from McMullen 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 McMullen County.
Total Sites
121
across McMullen County
Risk Level
Moderate
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
across McMullen County
Severity Distribution
across McMullen County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around McMullen County, Nitrate runs higher than the national average — 104 sites across McMullen County. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in McMullen 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 McMullen County average
Your land is one point inside McMullen County
Everything above resolves to McMullen County as a whole — one PHZM band and one county frost record, read across 729K 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 McMullen County Average
McMullen County Average
- ●USDA Zones 9a, averaged across McMullen County
- ●One soil character for all of McMullen County
- ●Frost dates read at McMullen County's scale: Jan 31 to Dec 8
YOUR Parcel
- ✓Your exact zone, not McMullen County's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in McMullen County
Pull a site-specific report for your exact address in McMullen County, Texas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that McMullen County averages can't show:
We read public map data around McMullen County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the McMullen County average
How we know this about McMullen 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 McMullen County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about McMullen County
When does frost risk typically end in McMullen County?
The last hard freeze (28°F) in McMullen County typically lands around Jan 31, 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 21.
How long is the growing season in McMullen County?
Measured between 28°F hard freezes, McMullen County sees about 311 frost-free days — roughly Jan 31 through Dec 8, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 21 to Nov 24, about 276 days.
Is the soil safe to grow vegetables in McMullen County?
The federal record around McMullen County shows 121 documented sites, mostly Nitrate entries (104), the nearest Underground Storage Tanks record about 2.5 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
Everything above is measured at McMullen County's scale — its 9a band and its 311-day season. Your yard writes its own version of McMullen 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 McMullen County’s own scale
9 of the readings below were taken at McMullen County's own scale — its own ~311-day span between 28°F freezes, the 3 most extensive soil series mapped here and 121 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- McMullen County's own USDA hardiness band, zones 9aUSDA PHZM 2023
- McMullen County's own 28°F hard-freeze dates and its ~311-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in McMullen CountyUSDA NRCS SSURGO
- 121 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 2.5 miles outFederal environmental registers
- McMullen County's boundary and the 729,471 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~311-day seasonGrowable Ground crop-matching engine
- McMullen County sitting wholly inside the Southern Texas PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in McMullen County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto McMullen 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 McMullen County — the ~311 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 McMullen County's 729,471 acreswhy one lot differs from the next →
- Which of those 121 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 McMullen Countyread your own land →