Chelsea, Oklahoma, sits in USDA hardiness zone 7a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
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 Chelsea, 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 Chelsea 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 Chelsea — soil, climate, flood, and parcel records. How we handle your address.
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Chelsea — the short answer
Chelsea, Oklahoma: USDA zone 7a, about 234 days between hard freezes, across 1K acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 23
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~234
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 1K 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 Chelsea's average, not your lot's — a low corner or a tree line moves it. Against Chelsea's 234-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Chelsea
Each reading below is measured for Chelsea itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredChelsea runs about 234 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
MeasuredChelsea 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 Chelsea is in
Chelsea sits in the Central Irregular Plains — EPA Level III, inside the wider Great Plains. That is read at Chelsea's own centroid rather than borrowed from Rogers County.
What Grows in Chelsea
Every plant below cleared Chelsea's own zone 7a and its 234-day season. Each card opens that plant's Oklahoma profile. How we score.
Is it too late to plant in Chelsea?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 23; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 12 — 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 Chelsea
Closest first, within ~10 miles of Chelsea. Listing isn't leaking, and distance isn't exposure.
- Eloms DxUnderground Storage Tanks · 1000 ft
- Former Green Country FuelUnderground Storage Tanks · 1300 ft
- Perfect Food And Gas 8Underground Storage Tanks · 1400 ft
- Dons Auto RepairUnderground Storage Tanks · 1900 ft
- GERBER COLLISION & GLASS - CLAREMOREBrownfields · 2000 ft
- Former Service StationUnderground Storage Tanks · 2300 ft
- Chelsea High SchoolUnderground Storage Tanks · 2400 ft
- Casey's General Store #3453Underground Storage Tanks · 2400 ft
- Pat's Full ServiceUnderground Storage Tanks · 2600 ft
- Family AffairUnderground Storage Tanks · 0.8 mi
- Grigsby's True Value HardwareUnderground Storage Tanks · 0.8 mi
- AAA GALVANIZING CHE/CHELSEA FACILITYToxics Release Inventory · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Chelsea'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 Chelsea.
Total Sites
24
within ~10 miles of Chelsea
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Chelsea
Severity Distribution
within ~10 miles of Chelsea
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •TRI facilities report what they release. Check the wind — downwind beds catch more of it.
Check your specific parcel in Chelsea
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 Chelsea average
Your land is one point inside Chelsea
Everything above resolves to Chelsea as a whole — one PHZM band and one 28°F frost record, read across 1K 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 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 Chelsea Average
Chelsea Average
- ●USDA Zones 7a, averaged across Chelsea
- ●One soil character for all of Chelsea
- ●Frost dates read at Chelsea's scale: Mar 23 to Nov 12
YOUR Parcel
- ✓Your exact zone, not Chelsea's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Chelsea
Pull a site-specific report for your exact address in Chelsea, Oklahoma — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Chelsea averages can't show:
We read public map data around Chelsea — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Chelsea average
How we know this about Chelsea
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 Chelsea’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 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 Chelsea
When does frost risk typically end in Chelsea?
The last hard freeze (28°F) in Chelsea typically lands around Mar 23, 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 13.
When is the first frost in Chelsea?
The first hard freeze (28°F) in Chelsea typically arrives around Nov 12, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 29, so the watching starts about Oct 13 — about 234 days after the spring freeze cleared.
How long is the growing season in Chelsea?
Measured between 28°F hard freezes, Chelsea sees about 234 frost-free days — roughly Mar 23 through Nov 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 13 to Oct 29, about 199 days.
Is the soil safe to grow vegetables in Chelsea?
The federal record around Chelsea is a meaningful one — 24 documented sites, mostly Underground Storage Tanks entries (17), 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 Chelsea?
From about Oct 13 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 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 Nov 12. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Chelsea's scale — its 7a band and its 234-day season. Your yard writes its own version of Chelsea'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 Chelsea’s own scale
6 of the readings below were taken at Chelsea's own scale — its own ~234-day season between 28°F freezes, the 1,137 acres it covers and 24 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Chelsea's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Chelsea's own 28°F hard-freeze dates, about Mar 23 and Nov 12 and the ~234-day span between themNOAA 1991–2020 Climate Normals
- 24 documented contamination sites on the federal record near Chelsea, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Chelsea's boundary and the 1,137 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~234-day seasonGrowable Ground crop-matching engine
- The ecoregion at Chelsea's own centroid, the Central Irregular PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Chelsea's 1,137 acres read through its county's SSURGO summaryfrom Rogers County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Rogers 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 Rogers County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Chelsea's 1,137 acreswhy one lot differs from the next →
- Which side of Chelsea you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,137 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 Chelsea-wide figureread your own land →
More in Oklahoma
Wider growing context
What grows across OklahomaChelsea sits outside our named growing regions, so Oklahoma as a whole is its closest context here.
Nearby growing guides