What Grows in Cerro Gordo County, Iowa

USDA Zones 5a · 364K acres

Cerro Gordo County, in Iowa, sits in USDA hardiness zone 5a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.

Expect sweet corn, tomato, apple, and hosta to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.

Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals

Score your parcel · free

Cerro Gordo County holds more than one microclimate.

Soils and elevations shift across Cerro Gordo County, so your frost dates and drainage aren't the county average. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

No card required · your full report in seconds

Quick Facts

USDA Zones

5a

Last Hard Freeze (28°F)

Apr 5

County normal — light frosts run a few weeks later

First Hard Freeze (28°F)

Nov 1

County normal — light frosts arrive a few weeks earlier

County Area

364K acres

Hardiness Zone Range

5a5a
3a (Cold)13b (Hot)

Zone maps are averages across Cerro Gordo County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.

Soil in Cerro Gordo County

Across Cerro Gordo County, the ground is predominantly Mollisols, where Clyde, Webster, and Kenyon are the most extensive named soil series. The soil is generally poorly drained with a loam surface. Topsoil pH runs about 6.2–6.7, slightly acidic. Rainfall drains through hydrologic group C/D soils.

Soil order

Mollisols

Drainage

Poorly drained

Prime farmland

48%

Hydric soils

37%

Soil still varies lot by lot — soil types explained.

Is it too late to plant in Cerro Gordo County?

Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 1 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.

Growing Challenges in Iowa

What an experienced grower plans around here — each one has a move.

Cold winters reaching -20F or below

Choose perennials rated a zone hardier than yours — Iowa winters test the margins, and the margin is where plants are lost.

Variable spring weather delays planting

Let soil temperature and your local frost normal call the start, not the calendar — a two-week wait beats a replant.

Wind exposure on open prairies desiccates plants

Even a simple windbreak — a shrub row, a snow fence, a tall cover crop — cuts wind desiccation dramatically.

For cultivar selection, pest pressure, and planting-time guidance specific to Iowa, the Iowa State University Extension and Outreach is the authoritative local source.

Safe to Grow Here?

What the federal record shows across Cerro Gordo County — and how to grow with it.

Federal record: High

We checked the federal record across Cerro Gordo County553 documented sites across 6 of the 9 source types we track.

The most significant on record: 5 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Cerro Gordo County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.

Sources: EPA, USGS1.8M documented sites tracked nationwide across 9 federal source types.

Environmental Intelligence

Understanding what's nearby helps you make informed decisions about where and how to grow.

Total Sites

553

across Cerro Gordo County

Risk Level

High

Highest-severity

5 Superfund sites

Severity Distribution

across Cerro Gordo County

High7Moderate197Low349

Highest-Severity Sites

Clear Lake Water Department
PFAS Sampling · PFAS Detected
Heidelberg Materials US Cement LLC
Superfund · Superfund (Non-NPL)
Mason City Coal Gasification Plant
Superfund · Superfund NPL
Mason City Water Department
PFAS Sampling · PFAS Detected
Northwestern States Portland Cement CO.
Superfund · Superfund NPL

Know Before You Grow

  • Underground tanks can leak petroleum products. Soil testing near former gas stations is recommended.
  • Test well water for nitrates if you rely on a private well. Levels above 10 mg/L require treatment.
  • Raised beds with imported soil can reduce exposure risk near brownfield sites.
Free Report

Check your specific parcel in Cerro Gordo County

Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.

Three things about your exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources analyzed in seconds

Your Specific Parcel Matters

Cerro Gordo County Average

  • USDA Zones 5a
  • Generic soil type for the area
  • State-average frost dates

YOUR Parcel

  • Your exact hardiness zone
  • Your SSURGO soil type & pH
  • Your sun exposure, cast in 3D

See MY Growing Report

Free Report

Read your parcel in Cerro Gordo County

Pull a site-specific report for your exact address in Cerro Gordo County, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.

Three things about your exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources analyzed in seconds

Key Growing Facts for Cerro Gordo County, Iowa

  • USDA Hardiness Zones: 5a (USDA PHZM 2023)
  • Last Hard Freeze (28°F): Apr 5 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
  • First Hard Freeze (28°F): Nov 1 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
  • Days Between Hard Freezes: ~210 (county normal, NOAA 1991–2020 Climate Normals)
  • County Land Area: 364K acres (US Census TIGER 2025)

Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. County boundaries: US Census TIGER/Line 2025.

Frost dates here are the Cerro Gordo County average. Low spots and tree cover move them by days on any one yard — see your exact frost windows.

Frequently Asked Questions

What hardiness zone is Cerro Gordo County, Iowa?

Cerro Gordo County sits in USDA hardiness zone 5a, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.

Is it too late to plant in Cerro Gordo County?

Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 1 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.

When does frost risk typically end in Cerro Gordo County?

The last hard freeze (28°F) in Cerro Gordo County typically lands around Apr 5, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.

How long is the growing season in Cerro Gordo County?

Measured between 28°F hard freezes, Cerro Gordo County sees about 210 frost-free days — roughly Apr 5 through Nov 1, per NOAA 1991–2020 climate normals. Tender crops get a somewhat shorter practical window, since lighter frosts reach a few weeks past the hard-freeze dates on both ends.

What vegetables grow in Cerro Gordo County?

Cerro Gordo County's zone 5a supports a wide range — strong performers include Sweet Corn, Tomato, Apple, and Hosta. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.

Which hardiness zone is Cerro Gordo County, really?

Officially, Cerro Gordo County sits in USDA zone 5a (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.

Is the soil safe to grow vegetables in Cerro Gordo County?

The federal record around Cerro Gordo County runs heavier than most — 553 documented sites — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.

Just moved to Cerro Gordo County — what should I know before planting?

Start with three facts. Cerro Gordo County sits in USDA zone 5a, which sets what survives winter; the last 28°F hard freeze typically clears around Apr 5, with about 210 frost-free days to work with (NOAA 1991–2020 climate normals); and 553 documented sites sit on the federal record here, so a soil test before food beds is the smart first step. From there, matching plants to your actual soil and sun is the fun part.

Everything on this page is a Cerro Gordo County average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.

Will It Grow Here?

Zone fit is the first question — each answer below reads Iowa's frost window, season length, and soil profile against the plant's real requirements.