Clarkson, Kentucky, sits in USDA hardiness zone 7a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Among the crops suited to this profile: cabbage, hazelnut, california poppy, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Clarkson, 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 Clarkson 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 Clarkson — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Clarkson — the short answer
Clarkson, Kentucky: USDA zone 7a, about 218 days between hard freezes, across 681 acres of city.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~218
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 681 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 7a is Clarkson's average, not your lot's — a low corner or a tree line moves it. Against Clarkson's 218-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Clarkson
Each reading below is measured for Clarkson itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredClarkson runs about 218 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredClarkson sits in USDA hardiness zone 7a.
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 Clarkson is in
Clarkson sits in the Interior Plateau — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Clarkson's own centroid, and it is not what its county reads: Grayson County is mostly Interior River Valleys and Hills. The wider page above you is answering a different question about different ground.
What Grows in Clarkson
Every plant below cleared Clarkson's own zone 7a and its 218-day season. Each card opens that plant's Kentucky profile. How we score.
Is it too late to plant in Clarkson?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Mar 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 5 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Documented around Clarkson
Survey cells within 31 miles of Clarkson checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 89 miles off. What to watch for.
What's on the federal record near Clarkson
Closest first, within ~10 miles of Clarkson. Listing isn't leaking, and distance isn't exposure.
- Central Service Station IncUnderground Storage Tanks · 1200 ft
- H15A0011Nitrate · 1300 ft
- One StopUnderground Storage Tanks · 1300 ft
- Hendersons SunocoUnderground Storage Tanks · 1900 ft
- Ready MartUnderground Storage Tanks · 2000 ft
- A & O Gas Co IncUnderground Storage Tanks · 2300 ft
- Lees Welding ServiceUnderground Storage Tanks · 2600 ft
- Former Clarkson Elementary SchoolUnderground Storage Tanks · 0.5 mi
- Midway GasUnderground Storage Tanks · 0.6 mi
- Cps Farm Service CenterUnderground Storage Tanks · 0.6 mi
- Clarkson Home Improvements IncUnderground Storage Tanks · 0.7 mi
- WALTER T KELLEY CO INCToxics Release Inventory · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Clarkson'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 Clarkson.
Total Sites
152
within ~10 miles of Clarkson
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Clarkson
Severity Distribution
within ~10 miles of Clarkson
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Clarkson, two things run higher than the national average within ~10 miles of Clarkson — PFAS (3 sites) and Underground Storage Tanks (107 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Clarkson
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 Clarkson average
Your land is one point inside Clarkson
Everything above resolves to Clarkson as a whole — one PHZM band and one 28°F frost record, read across 681 acres. 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 Clarkson Average
Clarkson Average
- ●USDA Zones 7a, averaged across Clarkson
- ●One soil character for all of Clarkson
- ●Frost dates read at Clarkson's scale: Apr 1 to Nov 5
YOUR Parcel
- ✓Your exact zone, not Clarkson's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Clarkson
Pull a site-specific report for your exact address in Clarkson, Kentucky — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Clarkson averages can't show:
We read public map data around Clarkson — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Clarkson average
How we know this about Clarkson
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 Clarkson’s own record; 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 Clarkson
When does frost risk typically end in Clarkson?
The last hard freeze (28°F) in Clarkson typically lands around Apr 1, 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 Apr 22.
When is the first frost in Clarkson?
The first hard freeze (28°F) in Clarkson typically arrives around Nov 5, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 22, so the watching starts about Oct 6 — about 218 days after the spring freeze cleared.
How long is the growing season in Clarkson?
Measured between 28°F hard freezes, Clarkson sees about 218 frost-free days — roughly Apr 1 through Nov 5, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 22 to Oct 22, about 183 days.
Is the soil safe to grow vegetables in Clarkson?
The federal record around Clarkson is a meaningful one — 152 documented sites, mostly Underground Storage Tanks entries (107), 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 Clarkson?
From about Oct 6 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 5 (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 5. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Clarkson's scale — its 7a band and its 218-day season. Your yard writes its own version of Clarkson'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 Clarkson’s own scale
7 of the readings below were taken at Clarkson's own scale — its own ~218-day season between 28°F freezes, the 681 acres it covers and 152 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Clarkson's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Clarkson's own 28°F hard-freeze dates, about Apr 1 and Nov 5 and the ~218-day span between themNOAA 1991–2020 Climate Normals
- 152 documented contamination sites on the federal record near Clarkson, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Clarkson's boundary and the 681 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~218-day seasonGrowable Ground crop-matching engine
- Clarkson sits in the Interior Plateau — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
- Lanternfly survey cells around Clarkson checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Clarkson's 681 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 Kentucky grower plans around — written at state scale, so they stay on the state guidefrom Kentucky
- 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 Clarkson's 681 acreswhy one lot differs from the next →
- Which side of Clarkson you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 681 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 Clarkson-wide figureread your own land →