Guymon, Oklahoma, sits in USDA hardiness zone 6b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Growers here do well with cabbage, hazelnut, lavender, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Guymon, 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 Guymon 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 Guymon — soil, climate, flood, and parcel records. How we handle your address.
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Guymon — the short answer
Guymon, Oklahoma: USDA zone 6b, about 203 days between hard freezes, across 5K acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 30
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~203
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 5K 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 6b is Guymon's average, not your lot's — a low corner or a tree line moves it. Against Guymon's 203-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Guymon
Each reading below is measured for Guymon itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGuymon runs about 203 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
MeasuredGuymon sits in USDA hardiness zone 6b.
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 Guymon is in
Guymon sits in the High Plains — EPA Level III, inside the wider Great Plains. That is read at Guymon's own centroid rather than borrowed from Texas County.
What Grows in Guymon
Every plant below cleared Guymon's own zone 6b and its 203-day season. Each card opens that plant's Oklahoma profile. How we score.
Is it too late to plant in Guymon?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 13; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 10 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 30 — 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.
What's on the federal record near Guymon
Closest first, within ~10 miles of Guymon. Listing isn't leaking, and distance isn't exposure.
- QUALITY CLNR GUYMON / 311 NE 12TH QUALITY CLEANERSBrownfields · 500 ft
- UNITED PARCEL SERVICE, INC. (GUYMON)Brownfields · 1000 ft
- Mary Kay's C StoreUnderground Storage Tanks · 1100 ft
- Guymon Town Storage YardUnderground Storage Tanks · 1200 ft
- Dizzy B's Corner MartUnderground Storage Tanks · 1400 ft
- Waynes TexacoUnderground Storage Tanks · 1400 ft
- GUYMON PAINT & BODYBrownfields · 1500 ft
- Yesway #1080Underground Storage Tanks · 1800 ft
- Superior ConcreteUnderground Storage Tanks · 1900 ft
- City WarehouseUnderground Storage Tanks · 2000 ft
- Formerly Bob's TotalUnderground Storage Tanks · 2200 ft
- MASTER CLNR AND LAUNDRY / 712 N MAIN MASTER CLEANERSBrownfields · 2300 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Guymon'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 Guymon.
Total Sites
162
within ~10 miles of Guymon
Risk Level
Moderate
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Guymon
Severity Distribution
within ~10 miles of Guymon
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Guymon, two things run higher than the national average within ~10 miles of Guymon — CAFO (8 sites) and Nitrate (68 sites). That's not a problem with your land — it's information about it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Guymon
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 Guymon average
Your land is one point inside Guymon
Everything above resolves to Guymon as a whole — one PHZM band and one 28°F frost record, read across 5K 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 Guymon Average
Guymon Average
- ●USDA Zones 6b, averaged across Guymon
- ●One soil character for all of Guymon
- ●Frost dates read at Guymon's scale: Apr 10 to Oct 30
YOUR Parcel
- ✓Your exact zone, not Guymon's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Guymon
Pull a site-specific report for your exact address in Guymon, Oklahoma — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Guymon averages can't show:
We read public map data around Guymon — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Guymon average
How we know this about Guymon
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 Guymon’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 Guymon
When does frost risk typically end in Guymon?
The last hard freeze (28°F) in Guymon typically lands around Apr 10, 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 May 1.
When is the first frost in Guymon?
The first hard freeze (28°F) in Guymon typically arrives around Oct 30, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 16, so the watching starts about Sep 30 — about 203 days after the spring freeze cleared.
How long is the growing season in Guymon?
Measured between 28°F hard freezes, Guymon sees about 203 frost-free days — roughly Apr 10 through Oct 30, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 1 to Oct 16, about 168 days.
Is the soil safe to grow vegetables in Guymon?
The federal record around Guymon shows 162 documented sites, mostly Underground Storage Tanks entries (69), the nearest Brownfields record under a tenth of a mile 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 Guymon?
From about Sep 30 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 Oct 30 (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 Oct 30. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Guymon's scale — its 6b band and its 203-day season. Your yard writes its own version of Guymon'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 Guymon’s own scale
6 of the readings below were taken at Guymon's own scale — its own ~203-day season between 28°F freezes, the 4,950 acres it covers and 162 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Guymon's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Guymon's own 28°F hard-freeze dates, about Apr 10 and Oct 30 and the ~203-day span between themNOAA 1991–2020 Climate Normals
- 162 documented contamination sites on the federal record near Guymon, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Guymon's boundary and the 4,950 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~203-day seasonGrowable Ground crop-matching engine
- The ecoregion at Guymon's own centroid, the High PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Guymon's 4,950 acres read through its county's SSURGO summaryfrom Texas County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Texas County
- The growing challenges every Oklahoma grower plans around — written at state scale, so they stay on the state guidefrom Oklahoma
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Texas County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Guymon's 4,950 acreswhy one lot differs from the next →
- Which side of Guymon you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 4,950 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record under a tenth of a mile 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 Guymon-wide figureread your own land →
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