Guthrie County, in 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.
Reliable performers under these conditions include cabbage, cranberry, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Guthrie County holds more than one microclimate.
Soils and elevations shift across Guthrie 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 Guthrie County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Guthrie County — the short answer
Guthrie County, Iowa: USDA zone 5a, about 179 days between hard freezes, across 378K acres.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 18
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 14
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~179
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 378K 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 Guthrie County's average, not your lot's — a low corner or a tree line moves it. Against Guthrie County's 179-day season, see what your own ground reads.
Heat in Guthrie County
Across a year, Guthrie County accumulates about 2,825 growing degree days above 50°F, about 81 more than the middle Iowa county — ahead of 57 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 Guthrie County
Across Guthrie County, the ground is predominantly Alfisols, where Colo, Clarion, and Gara are the most extensive named soil series. The soil is generally well drained with a silty clay loam surface. Topsoil pH runs about 6.0–6.5, slightly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
19%
Hydric soils
20%
Soil still varies lot by lot — soil types explained.
How the ground varies across Guthrie County
The USDA soil survey maps 37% of Guthrie County as well drained — but another 62% drains differently: 34% moderately well drained, 18% poorly drained.
Colo is the most extensive named soil at 10% of mapped acres, then Clarion (9%) and Gara (9%).
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 Guthrie County
Each reading below is measured for Guthrie 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 Guthrie 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 Guthrie County runs about pH 6.0–6.5, 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
Wet ground
MeasuredAbout 20% of Guthrie County is mapped as hydric — wetland — soil.
If your lot falls in one of those pockets, a standard in-ground bed will fight waterlogging all season, and roots that need air will struggle.
Check how your own ground drains before you dig; raised beds or moisture-loving plantings turn a wet corner from a problem into a niche.
USDA NRCS SSURGO
Season length
MeasuredGuthrie County runs about 179 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
The kind of country Guthrie County is in
Guthrie 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 Guthrie County
We scored all 1,086 plants against Guthrie County's own USDA zone 5a and its own 179-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 Guthrie County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 21; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 18 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 14 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
Documented around Guthrie County
- monarch butterfly79 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Guthrie County
USGS estimates 230,592 lb of Glyphosate on Guthrie County farmland in 2019, its largest by weight, ahead of Acetochlor (85,248 lb) and Metolachlor & Metolachlor-s (74,486 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 Guthrie County — and how to grow with it.
We checked the federal record across Guthrie County — 130 documented sites across 4 of the 9 source types we track.
The most significant on record: 5 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
The federal record across Guthrie County is a modest one — a typical footprint for a growing area. Nothing here calls for alarm; it's worth knowing which recorded sites sit closest to where you grow, and each one on the map carries its type and location. If one turns out to be a near neighbor, a one-time soil test settles the question.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Guthrie County
Closest first, across Guthrie County. Listing isn't leaking, and distance isn't exposure.
- GUTHRIE COUNTY PROPERTYUnderground Storage Tanks · 1400 ft
- UNITED PARCEL SERVICEUnderground Storage Tanks · 1400 ft
- CENTRAL IOWA FS INCUnderground Storage Tanks · 1400 ft
- WELLS VETERINARY CLINICUnderground Storage Tanks · 1400 ft
- IDOTUnderground Storage Tanks · 1400 ft
- GOLDMINE COUNTRY STOREUnderground Storage Tanks · 1800 ft
- CASEY''S GENERAL STORE 1534Underground Storage Tanks · 2200 ft
- CASEY''S GENERAL STOREUnderground Storage Tanks · 2300 ft
- SPARKY''S ONE STOP #17Underground Storage Tanks · 2300 ft
- FORMER GUTHRIE CENTER SCHOOL BUS GARAGEUnderground Storage Tanks · 2300 ft
- FORMER WARDROBE CLEANERSUnderground Storage Tanks · 2400 ft
- 079N31W06CDBC 1984Guthrie Center 1Nitrate · 2500 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Guthrie 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 Guthrie County.
Total Sites
130
across Guthrie County
Risk Level
Moderate
Highest-severity
5 Toxics Release Inventory facilities
Sources Checked
across Guthrie County
Severity Distribution
across Guthrie County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Guthrie County, Nitrate runs higher than the national average — 44 sites across Guthrie County. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Guthrie 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 Guthrie County average
Your land is one point inside Guthrie County
Everything above resolves to Guthrie County as a whole — one PHZM band and one county frost record, read across 378K 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 Guthrie County Average
Guthrie County Average
- ●USDA Zones 5a, averaged across Guthrie County
- ●One soil character for all of Guthrie County
- ●Frost dates read at Guthrie County's scale: Apr 18 to Oct 14
YOUR Parcel
- ✓Your exact zone, not Guthrie County's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Guthrie County
Pull a site-specific report for your exact address in Guthrie County, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Guthrie County averages can't show:
We read public map data around Guthrie County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Guthrie County average
How we know this about Guthrie 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 Guthrie County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Guthrie County
When does frost risk typically end in Guthrie County?
The last hard freeze (28°F) in Guthrie County typically lands around Apr 18, 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 9.
How long is the growing season in Guthrie County?
Measured between 28°F hard freezes, Guthrie County sees about 179 frost-free days — roughly Apr 18 through Oct 14, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 9 to Sep 30, about 144 days.
Is the soil safe to grow vegetables in Guthrie County?
The federal record around Guthrie County shows 130 documented sites, mostly Underground Storage Tanks entries (63), the nearest Underground Storage Tanks record about 0.3 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.
Everything above is measured at Guthrie County's scale — its 5a band and its 179-day season. Your yard writes its own version of Guthrie 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 Guthrie County’s own scale
9 of the readings below were taken at Guthrie County's own scale — its own ~179-day span between 28°F freezes, the 3 most extensive soil series mapped here and 130 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Guthrie County's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Guthrie County's own 28°F hard-freeze dates and its ~179-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Guthrie CountyUSDA NRCS SSURGO
- 130 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.3 miles outFederal environmental registers
- Guthrie County's boundary and the 377,993 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~179-day seasonGrowable Ground crop-matching engine
- Guthrie County sitting wholly inside the Western Corn Belt PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Guthrie County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Guthrie 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 Guthrie County — the ~179 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 Guthrie County's 377,993 acreswhy one lot differs from the next →
- Which of those 130 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 Guthrie Countyread your own land →