Allamakee 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.
Growers here do well with cabbage, cranberry, lavender, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Allamakee County lies within the Driftless Area — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Allamakee County holds more than one microclimate.
Soils and elevations shift across Allamakee 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 Allamakee County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Allamakee County — the short answer
Allamakee County, Iowa: USDA zone 5a, about 189 days between hard freezes, across 409K acres.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 16
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 22
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~189
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 409K 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 Allamakee County's average, not your lot's — a low corner or a tree line moves it. Against Allamakee County's 189-day season, see what your own ground reads.
Heat in Allamakee County
Across a year, Allamakee County accumulates about 2,426 growing degree days above 50°F, about 318 fewer than the middle Iowa county — ahead of 5 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 Allamakee County
Across Allamakee County, the ground is predominantly Alfisols, where Fayette, Downs, and Lacrescent are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 6.2–6.7, slightly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
13%
Hydric soils
4%
Soil still varies lot by lot — soil types explained.
How the ground varies across Allamakee County
The USDA soil survey maps 83% of Allamakee County as well drained — but another 13% drains differently: 5% moderately well drained, 4% poorly drained.
Fayette is the most extensive named soil at 25% of mapped acres, then Downs (14%) and Lacrescent (14%).
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 Allamakee County
Each reading below is measured for Allamakee 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 Allamakee 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 Allamakee County runs about pH 6.2–6.7, 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
MeasuredAllamakee County runs about 189 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
MeasuredAllamakee 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 Allamakee County is in
Allamakee County sits in the Driftless Area — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Allamakee County
We scored all 1,086 plants against Allamakee County's own USDA zone 5a and its own 189-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 Allamakee County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 19; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 16 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 22 — 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 Allamakee County
- monarch butterfly56 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Allamakee County
USGS estimates 121,899 lb of Glyphosate on Allamakee County farmland in 2019, its largest by weight, ahead of Acetochlor (67,641 lb) and Atrazine (41,723 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 Allamakee County — and how to grow with it.
We checked the federal record across Allamakee County — 160 documented sites across 7 of the 9 source types we track.
The most significant on record: 9 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
There's a meaningful federal record across Allamakee 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 Allamakee County
Closest first, across Allamakee County. Listing isn't leaking, and distance isn't exposure.
- 097N04W05ADAD 08327 1957Nitrate · 3.2 mi
- AVEKA NUTRA PROCESSINGBrownfields · 4.2 mi
- AVEKA NUTRA PROCESSINGToxics Release Inventory · 4.2 mi
- BIG G AUTO BODY REPAIRBrownfields · 4.2 mi
- NORTHEAST AUTOBODYBrownfields · 4.2 mi
- REGANCREST HOLSTEIN INC.CAFO · 4.3 mi
- IDOT MAINT GARAGEUnderground Storage Tanks · 4.4 mi
- WISCONSIN DAIRIES COOPUnderground Storage Tanks · 4.4 mi
- CROELL REDI-MIX, INC - WAUKONToxics Release Inventory · 4.5 mi
- GUNDERSEN LUTHERAN WAUKON CLINICBrownfields · 4.5 mi
- WAUKON GOLF & COUNTRY CLUBUnderground Storage Tanks · 4.6 mi
- 098N05W30ACDC 08170 1957Waukon 4Nitrate · 4.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Allamakee 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 Allamakee County.
Total Sites
160
across Allamakee County
Risk Level
Elevated
Highest-severity
9 Toxics Release Inventory facilities
Sources Checked
across Allamakee County
Severity Distribution
across Allamakee County
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
Check your specific parcel in Allamakee 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 Allamakee County average
Your land is one point inside Allamakee County
Everything above resolves to Allamakee County as a whole — one PHZM band and one county frost record, read across 409K 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 Allamakee County Average
Allamakee County Average
- ●USDA Zones 5a, averaged across Allamakee County
- ●One soil character for all of Allamakee County
- ●Frost dates read at Allamakee County's scale: Apr 16 to Oct 22
YOUR Parcel
- ✓Your exact zone, not Allamakee County's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Allamakee County
Pull a site-specific report for your exact address in Allamakee County, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Allamakee County averages can't show:
We read public map data around Allamakee County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Allamakee County average
How we know this about Allamakee 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 Allamakee County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Allamakee County
When does frost risk typically end in Allamakee County?
The last hard freeze (28°F) in Allamakee County typically lands around Apr 16, 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 7.
How long is the growing season in Allamakee County?
Measured between 28°F hard freezes, Allamakee County sees about 189 frost-free days — roughly Apr 16 through Oct 22, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 7 to Oct 8, about 154 days.
Is the soil safe to grow vegetables in Allamakee County?
The federal record around Allamakee County is a meaningful one — 160 documented sites, mostly Underground Storage Tanks entries (85), the nearest Nitrate record about 3.2 miles 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 Allamakee County's scale — its 5a band and its 189-day season. Your yard writes its own version of Allamakee 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 Allamakee County’s own scale
9 of the readings below were taken at Allamakee County's own scale — its own ~189-day span between 28°F freezes, the 3 most extensive soil series mapped here and 160 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Allamakee County's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Allamakee County's own 28°F hard-freeze dates and its ~189-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Allamakee CountyUSDA NRCS SSURGO
- 160 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 3.2 miles outFederal environmental registers
- Allamakee County's boundary and the 409,005 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~189-day seasonGrowable Ground crop-matching engine
- Allamakee County sitting wholly inside the Driftless AreaUS EPA Level III Ecoregions
- Open occurrence records documented in Allamakee County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Allamakee 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 Allamakee County — the ~189 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 Allamakee County's 409,005 acreswhy one lot differs from the next →
- Which of those 160 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 Allamakee Countyread your own land →