Le Roy, Iowa, sits in USDA hardiness zone 5b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
The conditions favor cabbage, cranberry, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Le Roy, 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 Le Roy 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 Le Roy — soil, climate, flood, and parcel records. How we handle your address.
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Le Roy — the short answer
Le Roy, Iowa: USDA zone 5b, about 194 days between hard freezes, across 243 acres of city.
- USDA zone
- 5b
- 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 21
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~194
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 243 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 Le Roy's average, not your lot's — a low corner or a tree line moves it. Against Le Roy's 194-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Le Roy
Each reading below is measured for Le Roy itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredLe Roy runs about 194 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
MeasuredLe Roy 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 Le Roy is in
Le Roy sits in the Central Irregular Plains — EPA Level III, inside the wider Great Plains. That is read at Le Roy's own centroid rather than borrowed from Decatur County.
What Grows in Le Roy
Every plant below cleared Le Roy's own zone 5b and its 194-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Le Roy?
Almost never — the real question is what to plant next. 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 21 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Le Roy
Closest first, within ~10 miles of Le Roy. Listing isn't leaking, and distance isn't exposure.
- MORMON TRAIL JR-SR HIGH SCHOOLBrownfields · 3.6 mi
- MORMON TRAIL COMM SCHOOLUnderground Storage Tanks · 3.6 mi
- TOM MOSERUnderground Storage Tanks · 3.6 mi
- GARDEN GROVE STOREUnderground Storage Tanks · 3.6 mi
- 070N24W34BBBA 09894 1958Garden Grove 1Nitrate · 3.7 mi
- 070N24W34BADA 03346 1948Garden Grove Test 2Nitrate · 3.8 mi
- 071N24W21BDB 1966Nitrate · 4.3 mi
- 071N23W29DBA 20073 1967Nitrate · 4.5 mi
- VANDELL AUTOMOTIVEUnderground Storage Tanks · 4.9 mi
- RAES AUTO REPAIRBrownfields · 4.9 mi
- CASEY''S GENERAL STORE 1125Underground Storage Tanks · 5.0 mi
- 069N26W34BBBD 1971Nitrate · 5.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Le Roy'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 Le Roy.
Sources Checked
within ~10 miles of Le Roy
Severity Distribution
within ~10 miles of Le Roy
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Le Roy, Nitrate runs higher than the national average — 26 sites within ~10 miles of Le Roy. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Le Roy
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 Le Roy average
Your land is one point inside Le Roy
Everything above resolves to Le Roy as a whole — one PHZM band and one 28°F frost record, read across 243 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 Le Roy Average
Le Roy Average
- ●USDA Zones 5b, averaged across Le Roy
- ●One soil character for all of Le Roy
- ●Frost dates read at Le Roy's scale: Apr 10 to Oct 21
YOUR Parcel
- ✓Your exact zone, not Le Roy's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Le Roy
Pull a site-specific report for your exact address in Le Roy, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Le Roy averages can't show:
We read public map data around Le Roy — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Le Roy average
How we know this about Le Roy
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 Le Roy’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 Le Roy
When does frost risk typically end in Le Roy?
The last hard freeze (28°F) in Le Roy 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 Le Roy?
The first hard freeze (28°F) in Le Roy typically arrives around Oct 21, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 7, so the watching starts about Sep 21 — about 194 days after the spring freeze cleared.
How long is the growing season in Le Roy?
Measured between 28°F hard freezes, Le Roy sees about 194 frost-free days — roughly Apr 10 through Oct 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 1 to Oct 7, about 159 days.
Is the soil safe to grow vegetables in Le Roy?
The federal record around Le Roy shows 46 documented sites, mostly Nitrate entries (26), the nearest Brownfields record about 3.6 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 Le Roy?
From about Sep 21 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 21 (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 21. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Le Roy's scale — its 5b band and its 194-day season. Your yard writes its own version of Le Roy'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 Le Roy’s own scale
6 of the readings below were taken at Le Roy's own scale — its own ~194-day season between 28°F freezes, the 243 acres it covers and 46 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Le Roy's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Le Roy's own 28°F hard-freeze dates, about Apr 10 and Oct 21 and the ~194-day span between themNOAA 1991–2020 Climate Normals
- 46 documented contamination sites on the federal record near Le Roy, the closest Brownfields record about 3.6 miles out from the town centreFederal environmental registers
- Le Roy's boundary and the 243 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~194-day seasonGrowable Ground crop-matching engine
- The ecoregion at Le Roy's own centroid, the Central Irregular PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Le Roy's 243 acres read through its county's SSURGO summaryfrom Decatur County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Decatur 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 Decatur County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Le Roy's 243 acreswhy one lot differs from the next →
- Which side of Le Roy you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 243 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 3.6 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 Le Roy-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaLe Roy sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides