Sienna, 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.
Reliable performers under these conditions include okra, meyer lemon, california poppy, and artichoke; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Sienna, 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 Sienna 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 Sienna — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Sienna — the short answer
Sienna, Texas: USDA zone 9b, about 319 days between hard freezes, across 8K acres of town.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 27
- Fort Bend County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 12
- Fort Bend County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~319
- Fort Bend County normal — NOAA 1991–2020, nearest to this town
- Town area
- 8K 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 Fort Bend County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9b is Sienna's average, not your lot's — a low corner or a tree line moves it. Against Sienna's 319-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Sienna
Each reading below is measured for Sienna itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsSienna runs about 319 days between hard freezes (read from Fort Bend County, the closest normal to Sienna) — 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
MeasuredSienna sits in USDA hardiness zone 9b.
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 Sienna is in
Sienna sits in the Western Gulf Coastal Plain — EPA Level III, inside the wider Great Plains. That is read at Sienna's own centroid rather than borrowed from Fort Bend County.
What Grows in Sienna
Every plant below cleared Sienna's own zone 9b and its 319-day season. Each card opens that plant's Texas profile. How we score.
Is it too late to plant in Sienna?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Jan 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jan 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 12 — 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.
Documented around Sienna
Survey cells within 31 miles of Sienna checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 488 miles off. What to watch for.
What's on the federal record near Sienna
Closest first, within ~10 miles of Sienna. Listing isn't leaking, and distance isn't exposure.
- CVS PHARMACY #11067Brownfields · 0.9 mi
- ACCPBrownfields · 1.7 mi
- CEMEX CONSTRUCTION MATERIALS HOUSTON, LLC - ARCOLA RMToxics Release Inventory · 1.9 mi
- TIMEWISE FOOD STORE 066 00Underground Storage Tanks · 2.1 mi
- ARCOLA FOOD MARTUnderground Storage Tanks · 2.2 mi
- HOUSTON SOUTHWEST AIRPORTUnderground Storage Tanks · 2.7 mi
- TEAL RUN EXXONUnderground Storage Tanks · 2.7 mi
- BLAZE TRANSPORTBrownfields · 2.7 mi
- 7-ELEVEN STORE 41000Underground Storage Tanks · 2.8 mi
- CAMPBELL PLANT 30 ARCOLAToxics Release Inventory · 2.8 mi
- SENIORS COUNTRY STOREUnderground Storage Tanks · 2.9 mi
- MARTIN MARIETTA MATERIALS ARCOLA PLANTToxics Release Inventory · 2.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Sienna'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 Sienna.
Total Sites
427
within ~10 miles of Sienna
Risk Level
High
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Sienna
Severity Distribution
within ~10 miles of Sienna
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Sienna, two things run higher than the national average within ~10 miles of Sienna — PFAS (22 sites) and Toxics Release Inventory (27 sites). That's not a problem with your land — it's information about it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Toxics 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 Sienna
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 Sienna average
Your land is one point inside Sienna
Everything above resolves to Sienna as a whole — one PHZM band, read across 8K acres, with hard-freeze dates borrowed from Fort Bend 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 Sienna Average
Sienna Average
- ●USDA Zones 9b, averaged across Sienna
- ●One soil character for all of Sienna
- ●Frost dates read at Sienna's scale: Jan 27 to Dec 12
YOUR Parcel
- ✓Your exact zone, not Sienna's 9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Sienna
Pull a site-specific report for your exact address in Sienna, Texas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Sienna averages can't show:
We read public map data around Sienna — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Sienna average
How we know this about Sienna
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 Fort Bend 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 Sienna
When does frost risk typically end in Sienna?
The last hard freeze (28°F) in Sienna typically lands around Jan 27, 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 17.
When is the first frost in Sienna?
The first hard freeze (28°F) in Sienna typically arrives around Dec 12, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 28, so the watching starts about Nov 12 — about 319 days after the spring freeze cleared.
How long is the growing season in Sienna?
Measured between 28°F hard freezes, Sienna sees about 319 frost-free days — roughly Jan 27 through Dec 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 17 to Nov 28, about 284 days.
Is the soil safe to grow vegetables in Sienna?
The federal record around Sienna runs heavier than most — 427 documented sites, mostly Underground Storage Tanks entries (251), the nearest Brownfields record about 0.9 miles out — 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.
How do I protect my plants from frost in Sienna?
From about Nov 12 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 12 (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 12. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Sienna's scale — its 9b band and its 319-day season. Your yard writes its own version of Sienna'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 Sienna’s own scale
6 of the readings below were taken at Sienna's own scale — the 8,052 acres it covers and 427 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Sienna's own USDA hardiness band, zones 9bUSDA PHZM 2023
- 427 documented contamination sites on the federal record near Sienna, the closest Brownfields record about 0.9 miles out from the town centreFederal environmental registers
- Sienna's boundary and the 8,052 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~319-day seasonGrowable Ground crop-matching engine
- The ecoregion at Sienna's own centroid, the Western Gulf Coastal PlainUS EPA Level III Ecoregions
- Lanternfly survey cells around Sienna checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- The 28°F hard-freeze dates — Sienna has no normal of its own, so its county's is the closest measured readfrom Fort Bend County
- Soil character — no town-scale survey exists, so Sienna's 8,052 acres read through its county's SSURGO summaryfrom Fort Bend County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Fort Bend 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 Fort Bend County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Sienna's 8,052 acreswhy one lot differs from the next →
- Which side of Sienna you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 8,052 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.9 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 Sienna-wide figureread your own land →
More in Texas
Wider growing context
What grows across TexasSienna sits outside our named growing regions, so Texas as a whole is its closest context here.
Nearby growing guides