Harris County, in Texas, sits in USDA hardiness zone 9b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Growers here do well with pecan, tomato, okra, and bluebonnet — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring
Harris County holds more than one microclimate.
Soils and elevations shift across Harris 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.
No card required · your full report in seconds
Quick Facts
USDA Zones
9b
Last Frost (state avg.)
Feb 1 - Apr 15
First Frost (state avg.)
Oct 15 - Dec 15
County Area
1.1M acres
Hardiness Zone Range
Growing Season
Zone maps are averages across Harris County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Harris County
Across Harris County, the ground is predominantly Alfisols, where Lake Charles, Clodine, and Bernard are the most extensive named soil series. The soil is generally somewhat poorly drained with a fine sandy loam surface. Topsoil pH runs about 5.3–6.8, moderately acidic. Rainfall drains through hydrologic group D soils.
Soil order
Alfisols
Drainage
Somewhat poorly drained
Prime farmland
22%
Hydric soils
29%
Soil still varies lot by lot — soil types explained.
What Grows in Harris County
Plants matched to Harris 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 Harris County — and how to grow with it.
We checked the federal record across Harris County — 12,699 documented sites across 8 of the 9 source types we track.
The most significant on record: 89 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Harris County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
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.
Severity Distribution
across Harris County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Harris County, two things run higher than the national average — PFAS (260 sites) and Toxic Release Inventory (1,031 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.
Toxic Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Harris 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
Harris 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 Harris County
Pull a site-specific report for your exact address in Harris 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 Harris 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: 1.1M 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 Harris 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 Harris County, Texas?
Harris 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 Harris County?
Harris 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 Harris County?
Harris 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 Harris County, really?
Officially, Harris 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 Harris County?
The federal record around Harris County runs heavier than most — 12,699 documented sites — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
Just moved to Harris County — what should I know before planting?
Start with three facts. Harris 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 12,699 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 Harris 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.