Clinton, Iowa, sits in USDA hardiness zone 5b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
On paper, cabbage, cranberry, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Clinton, 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 Clinton 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 Clinton — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Clinton — the short answer
Clinton, Iowa: USDA zone 5b, about 201 days between hard freezes, across 23K acres of city.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 8
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~201
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 23K 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 5b is Clinton's average, not your lot's — a low corner or a tree line moves it. Against Clinton's 201-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Clinton
Each reading below is measured for Clinton itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredClinton runs about 201 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
MeasuredClinton sits in USDA hardiness zone 5b.
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 Clinton is in
Clinton sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Clinton's own centroid rather than borrowed from Clinton County.
What Grows in Clinton
Every plant below cleared Clinton's own zone 5b and its 201-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Clinton?
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 11; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 8 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 26 — 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 Clinton
Closest first, within ~10 miles of Clinton. Listing isn't leaking, and distance isn't exposure.
- B & E MACHINE CO INCBrownfields · 0.9 mi
- 081N06E11CDD 05220 1952Clinton 9Nitrate · 1.1 mi
- ROSE'S WOOD PRODUCTSToxics Release Inventory · 1.1 mi
- BLUFF 76 SERVICEUnderground Storage Tanks · 1.1 mi
- BLUFF 76 SERVICEBrownfields · 1.1 mi
- SWISS VALLEY FARMS COUnderground Storage Tanks · 1.2 mi
- HENRY LANGREHR GEN CONTR INCUnderground Storage Tanks · 1.2 mi
- RINGLAND-JOHNSONUnderground Storage Tanks · 1.2 mi
- COLLIS INC-SSW ENTERPRISESBrownfields · 1.3 mi
- COLLIS INC-SSW ENTERPRISESToxics Release Inventory · 1.3 mi
- NESTLE' PURINA PETCARE COMPANY - CLINTONToxics Release Inventory · 1.3 mi
- NESTLE' PURINA PETCARE COMPANY - CLINTONBrownfields · 1.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Clinton'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 Clinton.
Sources Checked
within ~10 miles of Clinton
Severity Distribution
within ~10 miles of Clinton
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Clinton, Toxics Release Inventory runs higher than the national average — 33 sites within ~10 miles of Clinton. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Clinton
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 Clinton average
Your land is one point inside Clinton
Everything above resolves to Clinton as a whole — one PHZM band and one 28°F frost record, read across 23K 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 Clinton Average
Clinton Average
- ●USDA Zones 5b, averaged across Clinton
- ●One soil character for all of Clinton
- ●Frost dates read at Clinton's scale: Apr 8 to Oct 26
YOUR Parcel
- ✓Your exact zone, not Clinton's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Clinton
Pull a site-specific report for your exact address in Clinton, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Clinton averages can't show:
We read public map data around Clinton — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Clinton average
How we know this about Clinton
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 Clinton’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 Clinton
When does frost risk typically end in Clinton?
The last hard freeze (28°F) in Clinton typically lands around Apr 8, 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 29.
When is the first frost in Clinton?
The first hard freeze (28°F) in Clinton typically arrives around Oct 26, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 12, so the watching starts about Sep 26 — about 201 days after the spring freeze cleared.
How long is the growing season in Clinton?
Measured between 28°F hard freezes, Clinton sees about 201 frost-free days — roughly Apr 8 through Oct 26, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 29 to Oct 12, about 166 days.
Is the soil safe to grow vegetables in Clinton?
The federal record around Clinton is a meaningful one — 355 documented sites, mostly Underground Storage Tanks entries (179), the nearest Brownfields record about 0.9 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 Clinton?
From about Sep 26 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 26 (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 26. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Clinton's scale — its 5b band and its 201-day season. Your yard writes its own version of Clinton'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 Clinton’s own scale
6 of the readings below were taken at Clinton's own scale — its own ~201-day season between 28°F freezes, the 22,784 acres it covers and 355 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Clinton's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Clinton's own 28°F hard-freeze dates, about Apr 8 and Oct 26 and the ~201-day span between themNOAA 1991–2020 Climate Normals
- 355 documented contamination sites on the federal record near Clinton, the closest Brownfields record about 0.9 miles out from the town centreFederal environmental registers
- Clinton's boundary and the 22,784 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~201-day seasonGrowable Ground crop-matching engine
- The ecoregion at Clinton's own centroid, the Western Corn Belt PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Clinton's 22,784 acres read through its county's SSURGO summaryfrom Clinton County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Clinton County
- The growing challenges every Iowa grower plans around — written at state scale, so they stay on the state guidefrom Iowa
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Clinton County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Clinton's 22,784 acreswhy one lot differs from the next →
- Which side of Clinton you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 22,784 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.9 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 Clinton-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaClinton sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides