Sonterra, Texas, sits in USDA hardiness zone 8b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Reliable performers under these conditions include cabbage, fig, california poppy, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Sonterra, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Sonterra lot. 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 Sonterra — soil, climate, flood, and parcel records. How we handle your address.
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Sonterra — the short answer
Sonterra, Texas: USDA zone 8b, about 292 days between hard freezes, across 2K acres of town.
- USDA zone
- 8b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 13
- Williamson County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 2
- Williamson County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~292
- Williamson County normal — NOAA 1991–2020, nearest to this town
- Town area
- 2K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are Williamson County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 8b is Sonterra's average, not your lot's — a low corner or a tree line moves it. Against Sonterra's 292-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Sonterra
Each reading below is measured for Sonterra itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsSonterra runs about 292 days between hard freezes (read from Williamson County, the closest normal to Sonterra) — 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
MeasuredSonterra sits in USDA hardiness zone 8b.
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 Sonterra is in
Sonterra sits in the Texas Blackland Prairies — EPA Level III, inside the wider Great Plains. That is read at Sonterra's own centroid rather than borrowed from Williamson County.
What Grows in Sonterra
Every plant below cleared Sonterra's own zone 8b and its 292-day season. Each card opens that plant's Texas profile. How we score.
Is it too late to plant in Sonterra?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Jan 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 2 — long-season crops need about 90 days of runway, quick greens only 30. With almost year-round growing weather, timing is about heat and rainfall more than frost — some bench is always in play.
What's on the federal record near Sonterra
Closest first, within ~10 miles of Sonterra. Listing isn't leaking, and distance isn't exposure.
- ZK-58-12-4 (Copper Ln)Nitrate · 2100 ft
- JARRELL SCHWERTNER WSCPFAS · 0.8 mi
- SONTERRA TRAVEL CENTERUnderground Storage Tanks · 1.0 mi
- CEFCO 42Underground Storage Tanks · 1.0 mi
- JARRELL TOWN CENTERUnderground Storage Tanks · 1.0 mi
- DOCS ONE STOPUnderground Storage Tanks · 1.2 mi
- BILLS CORNERUnderground Storage Tanks · 1.3 mi
- H & H MOBILUnderground Storage Tanks · 1.3 mi
- JARRELL TEXACOUnderground Storage Tanks · 1.3 mi
- JARRELL FARM SUPPLYUnderground Storage Tanks · 2.0 mi
- JARRELL FACILITYBrownfields · 2.0 mi
- JARRELL PLANTToxics Release Inventory · 2.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Sonterra'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 Sonterra.
Total Sites
57
within ~10 miles of Sonterra
Risk Level
Moderate
Highest-severity
10 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Sonterra
Severity Distribution
within ~10 miles of Sonterra
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Sonterra, two things run higher than the national average within ~10 miles of Sonterra — Toxics Release Inventory (10 sites) and Nitrate (18 sites). That's not a problem with your land — it's information about it.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Sonterra
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 Sonterra average
Your land is one point inside Sonterra
Everything above resolves to Sonterra as a whole — one PHZM band, read across 2K acres, with hard-freeze dates borrowed from Williamson County’s record because no 30-year normal resolves at this town’s own centroid. 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 town 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 local average.
Your Lot vs the Sonterra Average
Sonterra Average
- ●USDA Zones 8b, averaged across Sonterra
- ●One soil character for all of Sonterra
- ●Frost dates read at Sonterra's scale: Feb 13 to Dec 2
YOUR Parcel
- ✓Your exact zone, not Sonterra's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Sonterra
Pull a site-specific report for your exact address in Sonterra, Texas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Sonterra averages can't show:
We read public map data around Sonterra — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Sonterra average
How we know this about Sonterra
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Williamson County’s record, because none resolves here; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Sonterra
When does frost risk typically end in Sonterra?
The last hard freeze (28°F) in Sonterra typically lands around Feb 13, 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 6.
When is the first frost in Sonterra?
The first hard freeze (28°F) in Sonterra typically arrives around Dec 2, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 18, so the watching starts about Nov 2 — about 292 days after the spring freeze cleared.
How long is the growing season in Sonterra?
Measured between 28°F hard freezes, Sonterra sees about 292 frost-free days — roughly Feb 13 through Dec 2, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 6 to Nov 18, about 257 days.
Is the soil safe to grow vegetables in Sonterra?
The federal record around Sonterra shows 57 documented sites, mostly Underground Storage Tanks entries (21), the nearest Nitrate record about 0.4 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.
How do I protect my plants from frost in Sonterra?
From about Nov 2 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Dec 2 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Dec 2. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Sonterra's scale — its 8b band and its 292-day season. Your yard writes its own version of Sonterra's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Sonterra’s own scale
5 of the readings below were taken at Sonterra's own scale — the 1,514 acres it covers and 57 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Sonterra's own USDA hardiness band, zones 8bUSDA PHZM 2023
- 57 documented contamination sites on the federal record near Sonterra, the closest Nitrate record about 0.4 miles out from the town centreFederal environmental registers
- Sonterra's boundary and the 1,514 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8b and a ~292-day seasonGrowable Ground crop-matching engine
- The ecoregion at Sonterra's own centroid, the Texas Blackland PrairiesUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Sonterra has no normal of its own, so its county's is the closest measured readfrom Williamson County
- Soil character — no town-scale survey exists, so Sonterra's 1,514 acres read through its county's SSURGO summaryfrom Williamson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Williamson County
- The growing challenges every Texas grower plans around — written at state scale, so they stay on the state guidefrom Texas
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Williamson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Sonterra's 1,514 acreswhy one lot differs from the next →
- Which side of Sonterra you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,514 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.4 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Sonterra-wide figureread your own land →
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