Knollwood, Texas, sits in USDA hardiness zone 8a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
On paper, cabbage, fig, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Knollwood, 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 Knollwood 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 Knollwood — soil, climate, flood, and parcel records. How we handle your address.
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Knollwood — the short answer
Knollwood, Texas: USDA zone 8a, about 274 days between hard freezes, across 208 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
- 208 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 Knollwood's average, not your lot's — a low corner or a tree line moves it. Against Knollwood's 274-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Knollwood
Each reading below is measured for Knollwood itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsKnollwood runs about 274 days between hard freezes (read from Grayson County, the closest normal to Knollwood) — 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
MeasuredKnollwood 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 Knollwood is in
Knollwood sits in the Texas Blackland Prairies — EPA Level III, inside the wider Great Plains. That is read at Knollwood's own centroid rather than borrowed from Grayson County.
What Grows in Knollwood
Every plant below cleared Knollwood'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 Knollwood?
Almost never — the real question is what to plant next. 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. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.
What's on the federal record near Knollwood
Closest first, within ~10 miles of Knollwood. Listing isn't leaking, and distance isn't exposure.
- HOME DEPOT STORE 518Brownfields · 0.7 mi
- CENTRAL FREIGHT LINES SHERMANUnderground Storage Tanks · 0.7 mi
- TARGET STORE T1861Brownfields · 0.8 mi
- SHERMAN FACILITY-SWARTOUTUnderground Storage Tanks · 0.8 mi
- CONTINENTAL BAKINGUnderground Storage Tanks · 1.0 mi
- POWR-LIFTUnderground Storage Tanks · 1.2 mi
- SHERMAN GAS PLANTToxics Release Inventory · 1.2 mi
- GRAYSON COUNTY COLLEGEUnderground Storage Tanks · 1.2 mi
- SAMS CLUB 6350Underground Storage Tanks · 1.2 mi
- MURPHY USA 5658Underground Storage Tanks · 1.3 mi
- WALMART SUPERCENTER 947Brownfields · 1.3 mi
- TRACTOR SUPPLY #367Brownfields · 1.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Knollwood'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 Knollwood.
Total Sites
461
within ~10 miles of Knollwood
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Knollwood
Severity Distribution
within ~10 miles of Knollwood
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Knollwood, two things run higher than the national average within ~10 miles of Knollwood — Underground Storage Tanks (365 sites) and Toxics Release Inventory (35 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Knollwood
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 Knollwood average
Your land is one point inside Knollwood
Everything above resolves to Knollwood as a whole — one PHZM band, read across 208 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 Knollwood Average
Knollwood Average
- ●USDA Zones 8a, averaged across Knollwood
- ●One soil character for all of Knollwood
- ●Frost dates read at Knollwood's scale: Feb 27 to Nov 28
YOUR Parcel
- ✓Your exact zone, not Knollwood's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Knollwood
Pull a site-specific report for your exact address in Knollwood, Texas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Knollwood averages can't show:
We read public map data around Knollwood — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Knollwood average
How we know this about Knollwood
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 Knollwood
When does frost risk typically end in Knollwood?
The last hard freeze (28°F) in Knollwood 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 Knollwood?
The first hard freeze (28°F) in Knollwood 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 Knollwood?
Measured between 28°F hard freezes, Knollwood 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 Knollwood?
The federal record around Knollwood is a meaningful one — 461 documented sites, mostly Underground Storage Tanks entries (365), the nearest Brownfields record about 0.7 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 Knollwood?
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 Knollwood's scale — its 8a band and its 274-day season. Your yard writes its own version of Knollwood'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 Knollwood’s own scale
5 of the readings below were taken at Knollwood's own scale — the 208 acres it covers and 461 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Knollwood's own USDA hardiness band, zones 8aUSDA PHZM 2023
- 461 documented contamination sites on the federal record near Knollwood, the closest Brownfields record about 0.7 miles out from the town centreFederal environmental registers
- Knollwood's boundary and the 208 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~274-day seasonGrowable Ground crop-matching engine
- The ecoregion at Knollwood's own centroid, the Texas Blackland PrairiesUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Knollwood 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 Knollwood's 208 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 Knollwood's 208 acreswhy one lot differs from the next →
- Which side of Knollwood you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 208 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.7 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 Knollwood-wide figureread your own land →
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