Denison, Texas, sits in USDA hardiness zone 8a — 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 cabbage, fig, california poppy, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Denison, 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 Denison 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 Denison — soil, climate, flood, and parcel records. How we handle your address.
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Denison — the short answer
Denison, Texas: USDA zone 8a, about 274 days between hard freezes, across 19K acres of city.
- USDA zone
- 8a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 27
- Grayson County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 28
- Grayson County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~274
- Grayson County normal — NOAA 1991–2020, nearest to this town
- City area
- 19K 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 Grayson County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 8a is Denison's average, not your lot's — a low corner or a tree line moves it. Against Denison's 274-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Denison
Each reading below is measured for Denison itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsDenison runs about 274 days between hard freezes (read from Grayson County, the closest normal to Denison) — 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
MeasuredDenison sits in USDA hardiness zone 8a.
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 Denison is in
Denison sits in the East Central Texas Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Denison's own centroid, and it is not what its county reads: Grayson County is mostly Texas Blackland Prairies. The wider page above you is answering a different question about different ground.
What Grows in Denison
Every plant below cleared Denison's own zone 8a and its 274-day season. Each card opens that plant's Texas profile. How we score.
Is it too late to plant in Denison?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Jan 30; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 28 — long-season crops need about 90 days of runway, quick greens only 30. In a climate this gentle, “too late” hardly applies — the question becomes which crops prefer the cooler months ahead.
What's on the federal record near Denison
Closest first, within ~10 miles of Denison. Listing isn't leaking, and distance isn't exposure.
- FINA STA 023 2331 223Underground Storage Tanks · 1300 ft
- LUCKY STOP 9Underground Storage Tanks · 1400 ft
- POTTSBORO SOC T36613Underground Storage Tanks · 1500 ft
- LONE STAR FOOD STORE 34Underground Storage Tanks · 1600 ft
- LONE STAR FOOD STORE 90Underground Storage Tanks · 1600 ft
- J & W 30Underground Storage Tanks · 2200 ft
- LONE STAR FOOD STORE 36Underground Storage Tanks · 2500 ft
- COLE & SMITHEN CONSTRUCTIONUnderground Storage Tanks · 2500 ft
- COLE & SMITHEN CONSTUnderground Storage Tanks · 2500 ft
- WAL-MART NO 147Brownfields · 0.6 mi
- WAL-MART SUPERCENTER 147Underground Storage Tanks · 0.6 mi
- WALMART SUPERCENTER 147Brownfields · 0.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Denison'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 Denison.
Total Sites
350
within ~10 miles of Denison
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Denison
Severity Distribution
within ~10 miles of Denison
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Denison, two things run higher than the national average within ~10 miles of Denison — Toxics Release Inventory (29 sites) and Underground Storage Tanks (271 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Denison
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 Denison average
Your land is one point inside Denison
Everything above resolves to Denison as a whole — one PHZM band, read across 19K acres, with hard-freeze dates borrowed from Grayson County’s record because no 30-year normal resolves at this city’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 city 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 Denison Average
Denison Average
- ●USDA Zones 8a, averaged across Denison
- ●One soil character for all of Denison
- ●Frost dates read at Denison's scale: Feb 27 to Nov 28
YOUR Parcel
- ✓Your exact zone, not Denison's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Denison
Pull a site-specific report for your exact address in Denison, Texas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Denison averages can't show:
We read public map data around Denison — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Denison average
How we know this about Denison
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Grayson 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 city grain anywhere on this page — there is no city-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 Denison
When does frost risk typically end in Denison?
The last hard freeze (28°F) in Denison typically lands around Feb 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 Mar 20.
When is the first frost in Denison?
The first hard freeze (28°F) in Denison typically arrives around Nov 28, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 14, so the watching starts about Oct 29 — about 274 days after the spring freeze cleared.
How long is the growing season in Denison?
Measured between 28°F hard freezes, Denison sees about 274 frost-free days — roughly Feb 27 through Nov 28, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 20 to Nov 14, about 239 days.
Is the soil safe to grow vegetables in Denison?
The federal record around Denison is a meaningful one — 350 documented sites, mostly Underground Storage Tanks entries (271), 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.
How do I protect my plants from frost in Denison?
From about Oct 29 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 Nov 28 (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 Nov 28. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Denison's scale — its 8a band and its 274-day season. Your yard writes its own version of Denison'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 Denison’s own scale
5 of the readings below were taken at Denison's own scale — the 18,572 acres it covers and 350 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Denison's own USDA hardiness band, zones 8aUSDA PHZM 2023
- 350 documented contamination sites on the federal record near Denison, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Denison's boundary and the 18,572 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~274-day seasonGrowable Ground crop-matching engine
- Denison sits in the East Central Texas Plains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Denison has no normal of its own, so its county's is the closest measured readfrom Grayson County
- Soil character — no town-scale survey exists, so Denison's 18,572 acres read through its county's SSURGO summaryfrom Grayson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Grayson 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 Grayson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Denison's 18,572 acreswhy one lot differs from the next →
- Which side of Denison you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 18,572 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 Denison-wide figureread your own land →
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