Starr County, in Texas, sits in USDA hardiness zone 9b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Crops well matched to these conditions include pecan, tomato, okra, and bluebonnet — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Starr County lies within the Rio Grande Valley — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring
Starr County holds more than one microclimate.
Soils and elevations shift across Starr County, so your frost dates and drainage aren't the county average. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Quick Facts
USDA Zones
9b
Last Frost (state avg.)
Feb 1 - Apr 15
First Frost (state avg.)
Oct 15 - Dec 15
County Area
783K acres
Hardiness Zone Range
Growing Season
Zone maps are averages across Starr County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Starr County
Across Starr County, the ground is predominantly Inceptisols, where McAllen, Copita, and Zapata are the most extensive named soil series. The soil is generally well drained with a fine sandy loam surface. Topsoil pH runs about 7.6–8.2, slightly alkaline. Rainfall drains through hydrologic group B soils.
Soil order
Inceptisols
Drainage
Well drained
Prime farmland
1%
Hydric soils
1%
Soil still varies lot by lot — soil types explained.
What Grows in Starr County
Plants matched to Starr County's USDA zones 9b — each links to its full growing profile.
Growing Challenges in Texas
What an experienced grower plans around here — each one has a move.
Extreme heat (100F+ days) stresses many crops from June through September
Run the garden on spring and fall windows and give summer survivors afternoon shade — timing beats fighting the heat.
Rainfall varies dramatically — 8 inches in west TX to 56 inches in east TX
Your county's rainfall, not the state's, sets the watering plan — check your exact spot before designing beds.
Heavy black clay (Blackland Prairie) is difficult to work and drains poorly
A raised bed with amended soil turns Blackland clay from an obstacle into a backdrop — and that clay feeds deep roots well.
Flash drought conditions can develop rapidly even in wet years
Mulch deep and water deeply-but-rarely to grow drought-tough roots; a drip system pays for itself in the first dry summer.
For cultivar selection, pest pressure, and planting-time guidance specific to Texas, the Texas A&M AgriLife Extension Service is the authoritative local source.
Safe to Grow Here?
What the federal record shows across Starr County — and how to grow with it.
We checked the federal record across Starr County — 179 documented sites across 5 of the 9 source types we track.
The most significant on record: 1 Toxics Release Inventory facility. Active industrial facilities reporting chemical releases to air, water, and land.
There's a meaningful federal record across Starr 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.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Total Sites
179
across Starr County
Risk Level
Elevated
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
across Starr County
Severity Distribution
across Starr County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Starr County, two things run higher than the national average — PFAS (6 sites) and CAFO (3 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check your specific parcel in Starr County
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Starr County Average
- ●USDA Zones 9b
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Starr County
Pull a site-specific report for your exact address in Starr County, Texas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Starr County, Texas
- USDA Hardiness Zones: 9b (USDA PHZM 2023)
- Last Spring Frost (state avg.): Feb 1 - Apr 15 (NOAA 30-Year Climate Normals)
- First Fall Frost (state avg.): Oct 15 - Dec 15 (NOAA 30-Year Climate Normals)
- County Land Area: 783K acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. County boundaries: US Census TIGER/Line 2025.
Frost dates here are the Starr County average. Low spots and tree cover move them by days on any one yard — see your exact frost windows.
Frequently Asked Questions
What hardiness zone is Starr County, Texas?
Starr County sits in USDA hardiness zone 9b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
When does frost risk typically end in Starr County?
Starr County follows Texas's statewide frost window: last spring frost around Feb 1 - Apr 15 and first fall frost around Oct 15 - Dec 15, per NOAA 30-year climate normals (1991–2020). Frost dates shift with elevation and local microclimate, so watch your own site's cold pockets.
What vegetables grow in Starr County?
Starr County's zone 9b supports a wide range — strong performers include Pecan, Tomato, Okra, Bluebonnet, and Jalapeno. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Starr County, really?
Officially, Starr County sits in USDA zone 9b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Starr County?
The federal record around Starr County is a meaningful one — 179 documented sites — 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.
Just moved to Starr County — what should I know before planting?
Start with three facts. Starr County sits in USDA zone 9b, which sets what survives winter; the statewide frost window runs about Feb 1 - Apr 15 to Oct 15 - Dec 15 (NOAA 30-year climate normals); and 179 documented sites sit on the federal record here, so a soil test before food beds is the smart first step. From there, matching plants to your actual soil and sun is the fun part.
Everything on this page is a Starr County average. Your yard writes its own version — 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.