Comal 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.
Comal County lies within the Texas Hill Country — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Comal County holds more than one microclimate.
Soils and elevations shift across Comal 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 Comal County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Comal County — the short answer
Comal County, Texas: USDA zone 9a, about 295 days between hard freezes, across 358K acres.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 11
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Dec 3
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~295
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 358K 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 Comal County's average, not your lot's — a low corner or a tree line moves it. Against Comal County's 295-day season, see what your own ground reads.
Heat and winter chill in Comal County
Across a year, Comal County accumulates about 6,433 growing degree days above 50°F, about 609 more than the middle Texas county — ahead of 182 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 662 hours below 45°F, 433 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 Comal County
Across Comal County, the ground is predominantly Mollisols, where Comfort, Brackett, and Rumple are the most extensive named soil series. The soil is generally well drained with a clay surface. Topsoil pH runs about 7.5–8.2, slightly alkaline. Rainfall drains through hydrologic group D soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
14%
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Comal County
The USDA soil survey maps 91% of Comal County as well drained — but another 8% drains differently: 8% moderately well drained.
Comfort is the most extensive named soil at 24% of mapped acres, then Brackett (16%) and Rumple (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 Comal County
Each reading below is measured for Comal 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 Comal 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 Comal County runs about pH 7.5–8.2, 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
MeasuredComal County runs about 295 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
MeasuredComal 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 Comal County is in
Comal County spans 2 EPA Level III ecoregions — Edwards Plateau (88%) and Texas Blackland Prairies (12%). 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 Comal County
We scored all 1,086 plants against Comal County's own USDA zone 9a and its own 295-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 Comal 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 14; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 3 — long-season crops need about 90 days of runway, quick greens only 30. In a climate this gentle, “too late” hardly applies — the question becomes which crops prefer the cooler months ahead.
Documented around Comal County
Survey cells within 31 miles of Comal County checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 649 miles off. What to watch for.
- monarch butterfly377 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Comal County
USGS estimates 8,320 lb of 2,4-d on Comal County farmland in 2019, its largest by weight, ahead of Glyphosate (2,905 lb) and Atrazine (1,126 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 Comal County — and how to grow with it.
We checked the federal record across Comal County — 531 documented sites across 6 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 Comal 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 Comal County
Closest first, across Comal County. Listing isn't leaking, and distance isn't exposure.
- CANYON LAKE AIRPORTUnderground Storage Tanks · 1.2 mi
- CANYON CITY EXXONUnderground Storage Tanks · 1.2 mi
- CANYON MARINE SERVICEUnderground Storage Tanks · 1.2 mi
- SAC N PAC 507Underground Storage Tanks · 1.2 mi
- GIFFORD-HILL 72Underground Storage Tanks · 1.2 mi
- HEITKAMPP GROCERYUnderground Storage Tanks · 1.2 mi
- EMIL SEIDELUnderground Storage Tanks · 1.2 mi
- D&I AUTOMOTIVEUnderground Storage Tanks · 1.2 mi
- SPECIALIZED TRANSPORT SERVICEUnderground Storage Tanks · 1.2 mi
- PEDERNALES ELECTRIC COOPUnderground Storage Tanks · 1.2 mi
- INSTA LUBEUnderground Storage Tanks · 1.2 mi
- COMAL ISD BUS GARAGEUnderground Storage Tanks · 1.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Comal 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 Comal County.
Total Sites
531
across Comal County
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
across Comal County
Severity Distribution
across Comal County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Comal County, two things run higher than the national average across Comal County — PFAS (7 sites) and Nitrate (200 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Comal 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 Comal County average
Your land is one point inside Comal County
Everything above resolves to Comal County as a whole — one PHZM band and one county frost record, read across 358K 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 Comal County Average
Comal County Average
- ●USDA Zones 9a, averaged across Comal County
- ●One soil character for all of Comal County
- ●Frost dates read at Comal County's scale: Feb 11 to Dec 3
YOUR Parcel
- ✓Your exact zone, not Comal County's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Comal County
Pull a site-specific report for your exact address in Comal County, Texas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Comal County averages can't show:
We read public map data around Comal County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Comal County average
How we know this about Comal 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 Comal County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Comal County
When does frost risk typically end in Comal County?
The last hard freeze (28°F) in Comal County typically lands around Feb 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 Mar 4.
How long is the growing season in Comal County?
Measured between 28°F hard freezes, Comal County sees about 295 frost-free days — roughly Feb 11 through Dec 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 4 to Nov 19, about 260 days.
Is the soil safe to grow vegetables in Comal County?
The federal record around Comal County is a meaningful one — 531 documented sites, mostly Underground Storage Tanks entries (232), the nearest Underground Storage Tanks record about 1.2 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 Comal County's scale — its 9a band and its 295-day season. Your yard writes its own version of Comal 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 Comal County’s own scale
9 of the readings below were taken at Comal County's own scale — its own ~295-day span between 28°F freezes, the 3 most extensive soil series mapped here and 531 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Comal County's own USDA hardiness band, zones 9aUSDA PHZM 2023
- Comal County's own 28°F hard-freeze dates and its ~295-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Comal CountyUSDA NRCS SSURGO
- 531 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 1.2 miles outFederal environmental registers
- Comal County's boundary and the 358,103 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~295-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Comal County spans, Edwards Plateau the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Comal County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Comal 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 Comal County — the ~295 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 Comal County's 358,103 acreswhy one lot differs from the next →
- Which of those 531 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 Comal Countyread your own land →