Clemons, Iowa, sits in USDA hardiness zone 5a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
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 Clemons, 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 Clemons 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 Clemons — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Clemons — the short answer
Clemons, Iowa: USDA zone 5a, about 188 days between hard freezes, across 160 acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 14
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 19
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~188
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 160 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 5a is Clemons's average, not your lot's — a low corner or a tree line moves it. Against Clemons's 188-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Clemons
Each reading below is measured for Clemons itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredClemons runs about 188 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredClemons sits in USDA hardiness zone 5a.
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 Clemons is in
Clemons sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Clemons's own centroid rather than borrowed from Marshall County.
What Grows in Clemons
Every plant below cleared Clemons's own zone 5a and its 188-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Clemons?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 17; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 14 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 19 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What's on the federal record near Clemons
Closest first, within ~10 miles of Clemons. Listing isn't leaking, and distance isn't exposure.
- CLEMONS GRAIN & SUPPLY COUnderground Storage Tanks · 800 ft
- Not KnownUnderground Storage Tanks · 850 ft
- MARCIA''S PIT STOPUnderground Storage Tanks · 950 ft
- MARSHALL COUNTY SHEDUnderground Storage Tanks · 2.1 mi
- 085N20W32DCC 00171 1934Saint Anthony 1Nitrate · 2.1 mi
- MARSHALL COUNTY MAINTENANCE YARDUnderground Storage Tanks · 3.6 mi
- LEO DUNNUnderground Storage Tanks · 4.5 mi
- 084N20W35BBCNitrate · 4.6 mi
- MARA FARMS LTDUnderground Storage Tanks · 5.2 mi
- STORY COUNTY WIND ENERGY CENTERBrownfields · 6.0 mi
- ITC MIDWEST STORYBrownfields · 6.1 mi
- NORTHERN NATURAL GAS - STATE CENTER TBSBrownfields · 6.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Clemons'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 Clemons.
Sources Checked
within ~10 miles of Clemons
Severity Distribution
within ~10 miles of Clemons
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Clemons, Underground Storage Tanks runs higher than the national average — 43 sites within ~10 miles of Clemons. 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.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Clemons
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 Clemons average
Your land is one point inside Clemons
Everything above resolves to Clemons as a whole — one PHZM band and one 28°F frost record, read across 160 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 Clemons Average
Clemons Average
- ●USDA Zones 5a, averaged across Clemons
- ●One soil character for all of Clemons
- ●Frost dates read at Clemons's scale: Apr 14 to Oct 19
YOUR Parcel
- ✓Your exact zone, not Clemons's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Clemons
Pull a site-specific report for your exact address in Clemons, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Clemons averages can't show:
We read public map data around Clemons — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Clemons average
How we know this about Clemons
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 Clemons’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 Clemons
When does frost risk typically end in Clemons?
The last hard freeze (28°F) in Clemons typically lands around Apr 14, 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 5.
When is the first frost in Clemons?
The first hard freeze (28°F) in Clemons typically arrives around Oct 19, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 5, so the watching starts about Sep 19 — about 188 days after the spring freeze cleared.
How long is the growing season in Clemons?
Measured between 28°F hard freezes, Clemons sees about 188 frost-free days — roughly Apr 14 through Oct 19, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 5 to Oct 5, about 153 days.
Is the soil safe to grow vegetables in Clemons?
The federal record around Clemons shows 66 documented sites, mostly Underground Storage Tanks entries (43), the nearest Underground Storage Tanks record about 0.2 miles 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 Clemons?
From about Sep 19 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 19 (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 19. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Clemons's scale — its 5a band and its 188-day season. Your yard writes its own version of Clemons'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 Clemons’s own scale
6 of the readings below were taken at Clemons's own scale — its own ~188-day season between 28°F freezes, the 160 acres it covers and 66 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Clemons's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Clemons's own 28°F hard-freeze dates, about Apr 14 and Oct 19 and the ~188-day span between themNOAA 1991–2020 Climate Normals
- 66 documented contamination sites on the federal record near Clemons, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Clemons's boundary and the 160 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~188-day seasonGrowable Ground crop-matching engine
- The ecoregion at Clemons'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 Clemons's 160 acres read through its county's SSURGO summaryfrom Marshall County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Marshall 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 Marshall County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Clemons's 160 acreswhy one lot differs from the next →
- Which side of Clemons you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 160 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 Clemons-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaClemons sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides