Cedar County, in Iowa, sits in USDA hardiness zone 5a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Among the crops suited to this profile: cabbage, cranberry, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Cedar County holds more than one microclimate.
Soils and elevations shift across Cedar County, so your frost dates and drainage aren't the county average. 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 Cedar County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Cedar County — the short answer
Cedar County, Iowa: USDA zone 5a, about 190 days between hard freezes, across 371K acres.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 13
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 20
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~190
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 371K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 Cedar County's average, not your lot's — a low corner or a tree line moves it. Against Cedar County's 190-day season, see what your own ground reads.
Heat in Cedar County
Across a year, Cedar County accumulates about 2,739 growing degree days above 50°F, about 5 fewer than the middle Iowa county — ahead of 48 of Iowa’s 99 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Cedar County
Across Cedar County, the ground is predominantly Mollisols, where Tama, Fayette, and Downs are the most extensive named soil series. The soil is generally well drained with a silty clay loam surface. Topsoil pH runs about 6.2–6.5, slightly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
44%
Hydric soils
14%
Soil still varies lot by lot — soil types explained.
How the ground varies across Cedar County
The USDA soil survey maps 56% of Cedar County as well drained — but another 43% drains differently: 17% somewhat poorly drained, 16% poorly drained.
Tama is the most extensive named soil at 19% of mapped acres, then Fayette (16%) and Downs (10%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Cedar County
Each reading below is measured for Cedar County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Cedar County are well drained, in hydrologic group C — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Cedar County runs about pH 6.2–6.5, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredCedar County runs about 190 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
MeasuredCedar County 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 Cedar County is in
Cedar County sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. One consistent ecological setting across the whole county.
What Grows in Cedar County
We scored all 1,086 plants against Cedar County's own USDA zone 5a and its own 190-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Iowa profile.
Is it too late to plant in Cedar County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 20 — 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.
Documented around Cedar County
- monarch butterfly466 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Cedar County
USGS estimates 271,014 lb of Glyphosate on Cedar County farmland in 2019, its largest by weight, ahead of Atrazine (160,871 lb) and Metolachlor & Metolachlor-s (106,312 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Cedar County — and how to grow with it.
We checked the federal record across Cedar County — 241 documented sites across 5 of the 9 source types we track.
The most significant on record: 1 Superfund site (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Cedar County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Cedar County
Closest first, across Cedar County. Listing isn't leaking, and distance isn't exposure.
- CEDAR-JOHNSON FARM SERVICEUnderground Storage Tanks · 500 ft
- FORMER SQUEALERUnderground Storage Tanks · 650 ft
- 080N02W06BC 1966Tipton 6Nitrate · 850 ft
- 080N02W06BBB 03214 1948Tipton 4Nitrate · 850 ft
- 080N02W06BBB 02027 1945Tipton 3Nitrate · 850 ft
- MANATTS INCUnderground Storage Tanks · 1200 ft
- CITY OF TIPTONUnderground Storage Tanks · 1300 ft
- TIPTON COMMUNITY SCHOOLUnderground Storage Tanks · 1400 ft
- CEDAR COUNTY TIREUnderground Storage Tanks · 1500 ft
- 080N02W06BBCA TiptonNitrate · 1500 ft
- 080N02W06BBCA 1930Tipton 2Nitrate · 1500 ft
- 080N02W06BBCA 00002 1889Tipton 1Nitrate · 1500 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Cedar County'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 Cedar County.
Total Sites
241
across Cedar County
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
across Cedar County
Severity Distribution
across Cedar County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Cedar County, Nitrate runs higher than the national average — 84 sites across Cedar County. 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 Cedar County
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 Cedar County average
Your land is one point inside Cedar County
Everything above resolves to Cedar County as a whole — one PHZM band and one county frost record, read across 371K 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 county 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 county average.
Your Lot vs the Cedar County Average
Cedar County Average
- ●USDA Zones 5a, averaged across Cedar County
- ●One soil character for all of Cedar County
- ●Frost dates read at Cedar County's scale: Apr 13 to Oct 20
YOUR Parcel
- ✓Your exact zone, not Cedar County's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Cedar County
Pull a site-specific report for your exact address in Cedar County, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Cedar County averages can't show:
We read public map data around Cedar County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Cedar County average
How we know this about Cedar County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Cedar County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Cedar County
When does frost risk typically end in Cedar County?
The last hard freeze (28°F) in Cedar County typically lands around Apr 13, 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 4.
How long is the growing season in Cedar County?
Measured between 28°F hard freezes, Cedar County sees about 190 frost-free days — roughly Apr 13 through Oct 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 4 to Oct 6, about 155 days.
Is the soil safe to grow vegetables in Cedar County?
The federal record around Cedar County is a meaningful one — 241 documented sites, mostly Underground Storage Tanks entries (120), the nearest Underground Storage Tanks 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.
Everything above is measured at Cedar County's scale — its 5a band and its 190-day season. Your yard writes its own version of Cedar County's numbers: 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.
What this page reads at Cedar County’s own scale
9 of the readings below were taken at Cedar County's own scale — its own ~190-day span between 28°F freezes, the 3 most extensive soil series mapped here and 241 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Cedar County's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Cedar County's own 28°F hard-freeze dates and its ~190-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Cedar CountyUSDA NRCS SSURGO
- 241 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record under a tenth of a mile outFederal environmental registers
- Cedar County's boundary and the 370,855 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~190-day seasonGrowable Ground crop-matching engine
- Cedar County sitting wholly inside the Western Corn Belt PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Cedar County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Cedar County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Iowa grower plans around — written at state scale, so they stay on the state guidefrom Iowa
What this page can’t tell you
- How the season shifts across Cedar County — the ~190 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Cedar County's 370,855 acreswhy one lot differs from the next →
- Which of those 241 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Cedar Countyread your own land →