Ackworth, Iowa, sits in USDA hardiness zone 5b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
On paper, cabbage, cranberry, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Ackworth, 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 Ackworth 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 Ackworth — soil, climate, flood, and parcel records. How we handle your address.
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Ackworth — the short answer
Ackworth, Iowa: USDA zone 5b, about 198 days between hard freezes, across 352 acres of city.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 9
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 24
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~198
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 352 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 5b is Ackworth's average, not your lot's — a low corner or a tree line moves it. Against Ackworth's 198-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Ackworth
Each reading below is measured for Ackworth itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredAckworth runs about 198 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
MeasuredAckworth sits in USDA hardiness zone 5b.
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 Ackworth is in
Ackworth sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Ackworth's own centroid rather than borrowed from Warren County.
What Grows in Ackworth
Every plant below cleared Ackworth's own zone 5b and its 198-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Ackworth?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 12; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 9 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 24 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What's on the federal record near Ackworth
Closest first, within ~10 miles of Ackworth. Listing isn't leaking, and distance isn't exposure.
- US POST OFFICEUnderground Storage Tanks · 1000 ft
- 076N23W27DCD 22882 1971Nitrate · 1.3 mi
- DOWNING CONSTRUCTIONUnderground Storage Tanks · 1.4 mi
- 076N23W34ABD 23051 1971Nitrate · 1.5 mi
- 076N23W34ADDNitrate · 1.6 mi
- 076N23W36ADA 1943Nitrate · 2.0 mi
- CITY OF INDIANOLAUnderground Storage Tanks · 3.5 mi
- CENTRAL PAVING CORPORATIONUnderground Storage Tanks · 3.6 mi
- 076N22W17ADC 1951Nitrate · 3.6 mi
- CEMEN TECH INCUnderground Storage Tanks · 3.6 mi
- VANDERPOOL CONSTRUCTION INCBrownfields · 3.6 mi
- STERNQUIST CONSTRUCTION INCUnderground Storage Tanks · 3.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Ackworth'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 Ackworth.
Total Sites
195
within ~10 miles of Ackworth
Risk Level
Moderate
Highest-severity
2 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Ackworth
Severity Distribution
within ~10 miles of Ackworth
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Ackworth, Nitrate runs higher than the national average — 70 sites within ~10 miles of Ackworth. 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 Ackworth
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 Ackworth average
Your land is one point inside Ackworth
Everything above resolves to Ackworth as a whole — one PHZM band and one 28°F frost record, read across 352 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 Ackworth Average
Ackworth Average
- ●USDA Zones 5b, averaged across Ackworth
- ●One soil character for all of Ackworth
- ●Frost dates read at Ackworth's scale: Apr 9 to Oct 24
YOUR Parcel
- ✓Your exact zone, not Ackworth's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Ackworth
Pull a site-specific report for your exact address in Ackworth, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Ackworth averages can't show:
We read public map data around Ackworth — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Ackworth average
How we know this about Ackworth
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 Ackworth’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 Ackworth
When does frost risk typically end in Ackworth?
The last hard freeze (28°F) in Ackworth typically lands around Apr 9, 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 Apr 30.
When is the first frost in Ackworth?
The first hard freeze (28°F) in Ackworth typically arrives around Oct 24, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 10, so the watching starts about Sep 24 — about 198 days after the spring freeze cleared.
How long is the growing season in Ackworth?
Measured between 28°F hard freezes, Ackworth sees about 198 frost-free days — roughly Apr 9 through Oct 24, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 30 to Oct 10, about 163 days.
Is the soil safe to grow vegetables in Ackworth?
The federal record around Ackworth shows 195 documented sites, mostly Underground Storage Tanks entries (88), the nearest Underground Storage Tanks record about 0.2 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.
How do I protect my plants from frost in Ackworth?
From about Sep 24 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 24 (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 24. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Ackworth's scale — its 5b band and its 198-day season. Your yard writes its own version of Ackworth'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 Ackworth’s own scale
6 of the readings below were taken at Ackworth's own scale — its own ~198-day season between 28°F freezes, the 352 acres it covers and 195 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Ackworth's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Ackworth's own 28°F hard-freeze dates, about Apr 9 and Oct 24 and the ~198-day span between themNOAA 1991–2020 Climate Normals
- 195 documented contamination sites on the federal record near Ackworth, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Ackworth's boundary and the 352 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~198-day seasonGrowable Ground crop-matching engine
- The ecoregion at Ackworth'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 Ackworth's 352 acres read through its county's SSURGO summaryfrom Warren County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Warren 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 Warren County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Ackworth's 352 acreswhy one lot differs from the next →
- Which side of Ackworth you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 352 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 miles 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 Ackworth-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaAckworth sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides