Earlville, Iowa, sits in USDA hardiness zone 5a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Expect cabbage, cranberry, lavender, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Earlville, 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 Earlville 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 Earlville — soil, climate, flood, and parcel records. How we handle your address.
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Earlville — the short answer
Earlville, Iowa: USDA zone 5a, about 176 days between hard freezes, across 353 acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 19
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~176
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 353 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 Earlville's average, not your lot's — a low corner or a tree line moves it. Against Earlville's 176-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Earlville
Each reading below is measured for Earlville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredEarlville runs about 176 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
MeasuredEarlville 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 Earlville is in
Earlville sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Earlville's own centroid rather than borrowed from Delaware County.
What Grows in Earlville
Every plant below cleared Earlville's own zone 5a and its 176-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Earlville?
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 22; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 19 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 12 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
What's on the federal record near Earlville
Closest first, within ~10 miles of Earlville. Listing isn't leaking, and distance isn't exposure.
- THREE RIVERS FS COMPANY EARLVILLE NH3Brownfields · 400 ft
- PERDUE AGRIBUSINESSToxics Release Inventory · 450 ft
- ALS TEXACOUnderground Storage Tanks · 550 ft
- 088N04W36BCBB 1960Earlville 2Nitrate · 700 ft
- THREE RIVERS FS COMPANYUnderground Storage Tanks · 700 ft
- 088N04W36BCBB 1905Earlville 1Nitrate · 800 ft
- EARLVILLE OIL COUnderground Storage Tanks · 950 ft
- EARLVILLE CORNER STOPUnderground Storage Tanks · 1000 ft
- MILLER''S AUTO & REPAIRUnderground Storage Tanks · 1100 ft
- DELAWARE COUNTYUnderground Storage Tanks · 0.6 mi
- DEL-CO VET PHARMUnderground Storage Tanks · 2.4 mi
- FAUST GARAGE & GROCERYUnderground Storage Tanks · 3.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Earlville'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 Earlville.
Total Sites
214
within ~10 miles of Earlville
Risk Level
Elevated
Highest-severity
17 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Earlville
Severity Distribution
within ~10 miles of Earlville
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Earlville, Toxics Release Inventory runs higher than the national average — 17 sites within ~10 miles of Earlville. That's not a problem with your land — it's information about it.
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 Earlville
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 Earlville average
Your land is one point inside Earlville
Everything above resolves to Earlville as a whole — one PHZM band and one 28°F frost record, read across 353 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 Earlville Average
Earlville Average
- ●USDA Zones 5a, averaged across Earlville
- ●One soil character for all of Earlville
- ●Frost dates read at Earlville's scale: Apr 19 to Oct 12
YOUR Parcel
- ✓Your exact zone, not Earlville's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Earlville
Pull a site-specific report for your exact address in Earlville, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Earlville averages can't show:
We read public map data around Earlville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Earlville average
How we know this about Earlville
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 Earlville’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 Earlville
When does frost risk typically end in Earlville?
The last hard freeze (28°F) in Earlville typically lands around Apr 19, 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 10.
When is the first frost in Earlville?
The first hard freeze (28°F) in Earlville typically arrives around Oct 12, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 28, so the watching starts about Sep 12 — about 176 days after the spring freeze cleared.
How long is the growing season in Earlville?
Measured between 28°F hard freezes, Earlville sees about 176 frost-free days — roughly Apr 19 through Oct 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 10 to Sep 28, about 141 days.
Is the soil safe to grow vegetables in Earlville?
The federal record around Earlville is a meaningful one — 214 documented sites, mostly Underground Storage Tanks entries (126), the nearest Brownfields record under a tenth of a mile 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 Earlville?
From about Sep 12 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 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 Oct 12. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Earlville's scale — its 5a band and its 176-day season. Your yard writes its own version of Earlville'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 Earlville’s own scale
6 of the readings below were taken at Earlville's own scale — its own ~176-day season between 28°F freezes, the 353 acres it covers and 214 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Earlville's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Earlville's own 28°F hard-freeze dates, about Apr 19 and Oct 12 and the ~176-day span between themNOAA 1991–2020 Climate Normals
- 214 documented contamination sites on the federal record near Earlville, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Earlville's boundary and the 353 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~176-day seasonGrowable Ground crop-matching engine
- The ecoregion at Earlville'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 Earlville's 353 acres read through its county's SSURGO summaryfrom Delaware County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Delaware 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 Delaware County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Earlville's 353 acreswhy one lot differs from the next →
- Which side of Earlville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 353 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 Earlville-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaEarlville sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides