Grimes County, in Texas, sits in USDA hardiness zone 9a — a zone band wide enough that plant choice, not possibility, is the interesting question.
On paper, artichoke, fig, california poppy, and cabbage 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
Grimes County holds more than one microclimate.
Soils and elevations shift across Grimes 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 Grimes County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Grimes County — the short answer
Grimes County, Texas: USDA zone 9a, about 300 days between hard freezes, across 504K acres.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 7
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Dec 4
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~300
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 504K 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 Grimes County's average, not your lot's — a low corner or a tree line moves it. Against Grimes County's 300-day season, see what your own ground reads.
Heat and winter chill in Grimes County
Across a year, Grimes County accumulates about 6,732 growing degree days above 50°F, about 908 more than the middle Texas county — ahead of 195 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 548 hours below 45°F, 547 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 Grimes County
Across Grimes County, the ground is predominantly Alfisols, where Frelsburg, Shiro, and Huntsburg are the most extensive named soil series. The soil is generally moderately well drained with a fine sandy loam surface. Topsoil pH runs about 5.5–6.7, slightly acidic. Rainfall drains through hydrologic group D soils.
Soil order
Alfisols
Drainage
Moderately well drained
Prime farmland
14%
Hydric soils
3%
Soil still varies lot by lot — soil types explained.
How the ground varies across Grimes County
The USDA soil survey maps 63% of Grimes County as moderately well drained — but another 35% drains differently: 19% well drained, 16% somewhat poorly drained.
Frelsburg is the most extensive named soil at 6% of mapped acres, then Shiro (6%) and Huntsburg (5%).
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 Grimes County
Each reading below is measured for Grimes 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 Grimes County are moderately well drained, in hydrologic group D — roughly the middle of the drainage range.
This is close to the middle most vegetables prefer: it holds enough water to carry a crop between rains without staying waterlogged. The catch is that a wet spring or a low corner can still tip it soggy.
Plant on the site as-is for most crops, but keep the lowest, slowest-draining beds for moisture-tolerant plantings.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Grimes County runs about pH 5.5–6.7, 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
MeasuredGrimes County runs about 300 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
MeasuredGrimes 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 Grimes County is in
Grimes County spans 3 EPA Level III ecoregions — East Central Texas Plains (53%), Texas Blackland Prairies (32%) and South Central Plains (15%). 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 Grimes County
We scored all 1,086 plants against Grimes County's own USDA zone 9a and its own 300-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 Grimes 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 10; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 7 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 4 — long-season crops need about 90 days of runway, quick greens only 30. Here the calendar nearly circles: cool-season crops take the winter shift, and the next window is always close.
Documented around Grimes County
- monarch butterfly4 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Grimes County
USGS estimates 7,018 lb of 2,4-d on Grimes County farmland in 2019, its largest by weight, ahead of Glyphosate (6,292 lb) and Metolachlor & Metolachlor-s (3,944 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 Grimes County — and how to grow with it.
We checked the federal record across Grimes County — 379 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 Grimes 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 Grimes County
Closest first, across Grimes County. Listing isn't leaking, and distance isn't exposure.
- GRAIN BINUnderground Storage Tanks · 900 ft
- IOLA ISDUnderground Storage Tanks · 900 ft
- BATTS FERTILIZER SHOPUnderground Storage Tanks · 900 ft
- FRANKS GROCERYUnderground Storage Tanks · 900 ft
- CONTEL OF TEXASUnderground Storage Tanks · 900 ft
- GRIMES COUNTY PREC 2Underground Storage Tanks · 900 ft
- GARY FUQUA CONSTRUCTIONUnderground Storage Tanks · 900 ft
- SOUTHERN PACIFIC TRANSPORTUnderground Storage Tanks · 900 ft
- H C STONEHAM GENERAL STOREUnderground Storage Tanks · 900 ft
- MCKINLEY SERVICE CENTERUnderground Storage Tanks · 900 ft
- RAM FORGE & STEELUnderground Storage Tanks · 900 ft
- NAVASOTA TX VORUnderground Storage Tanks · 900 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Grimes 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 Grimes County.
Total Sites
379
across Grimes County
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
across Grimes County
Severity Distribution
across Grimes County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Grimes County, Nitrate runs higher than the national average — 228 sites across Grimes County. That's not a problem with your land — it's information about 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 Grimes 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 Grimes County average
Your land is one point inside Grimes County
Everything above resolves to Grimes County as a whole — one PHZM band and one county frost record, read across 504K 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 Grimes County Average
Grimes County Average
- ●USDA Zones 9a, averaged across Grimes County
- ●One soil character for all of Grimes County
- ●Frost dates read at Grimes County's scale: Feb 7 to Dec 4
YOUR Parcel
- ✓Your exact zone, not Grimes County's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Grimes County
Pull a site-specific report for your exact address in Grimes County, Texas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Grimes County averages can't show:
We read public map data around Grimes County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Grimes County average
How we know this about Grimes 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 Grimes County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Grimes County
When does frost risk typically end in Grimes County?
The last hard freeze (28°F) in Grimes County typically lands around Feb 7, 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 28.
How long is the growing season in Grimes County?
Measured between 28°F hard freezes, Grimes County sees about 300 frost-free days — roughly Feb 7 through Dec 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 28 to Nov 20, about 265 days.
Is the soil safe to grow vegetables in Grimes County?
The federal record around Grimes County is a meaningful one — 379 documented sites, mostly Nitrate entries (228), the nearest Underground Storage Tanks record about 0.2 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 Grimes County's scale — its 9a band and its 300-day season. Your yard writes its own version of Grimes 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 Grimes County’s own scale
9 of the readings below were taken at Grimes County's own scale — its own ~300-day span between 28°F freezes, the 3 most extensive soil series mapped here and 379 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Grimes County's own USDA hardiness band, zones 9aUSDA PHZM 2023
- Grimes County's own 28°F hard-freeze dates and its ~300-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Grimes CountyUSDA NRCS SSURGO
- 379 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.2 miles outFederal environmental registers
- Grimes County's boundary and the 503,980 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~300-day seasonGrowable Ground crop-matching engine
- The 3 ecoregions Grimes County spans, East Central Texas Plains the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Grimes County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Grimes 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 Grimes County — the ~300 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 Grimes County's 503,980 acreswhy one lot differs from the next →
- Which of those 379 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 Grimes Countyread your own land →