Terril, Iowa, sits in USDA hardiness zone 5a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Well-matched crops include cabbage, cranberry, lavender, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Terril, 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 Terril 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 Terril — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Terril — the short answer
Terril, Iowa: USDA zone 5a, about 180 days between hard freezes, across 348 acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 19
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~180
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 348 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 5a is Terril's average, not your lot's — a low corner or a tree line moves it. Against Terril's 180-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Terril
Each reading below is measured for Terril itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredTerril runs about 180 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
MeasuredTerril 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 Terril is in
Terril sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Terril's own centroid rather than borrowed from Dickinson County.
What Grows in Terril
Every plant below cleared Terril's own zone 5a and its 180-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Terril?
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 22; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 19 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 16 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
What's on the federal record near Terril
Closest first, within ~10 miles of Terril. Listing isn't leaking, and distance isn't exposure.
- C L TORRESONUnderground Storage Tanks · 550 ft
- DICKINSON COUNTYUnderground Storage Tanks · 550 ft
- FARMERS COOPUnderground Storage Tanks · 1100 ft
- 098N35W15CBBB 1981Terril 2Nitrate · 1100 ft
- GREEN PLAINS ENERGYUnderground Storage Tanks · 1200 ft
- TERRIL COMMUNITY SCHOOL DISTRICTBrownfields · 1200 ft
- 098N35W16ADDD 1947Terril 1Nitrate · 1400 ft
- DON KRIEGERUnderground Storage Tanks · 1400 ft
- 099N35W30DDB 06960 1954Nitrate · 4.3 mi
- 098N36W24BCC 02909 1947Nitrate · 4.4 mi
- MARLERS RESORTUnderground Storage Tanks · 6.4 mi
- DEWEYS PASTUREUnderground Storage Tanks · 6.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Terril'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 Terril.
Total Sites
166
within ~10 miles of Terril
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Terril
Severity Distribution
within ~10 miles of Terril
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Terril, Underground Storage Tanks runs higher than the national average — 103 sites within ~10 miles of Terril. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Terril
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 Terril average
Your land is one point inside Terril
Everything above resolves to Terril as a whole — one PHZM band and one 28°F frost record, read across 348 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 Terril Average
Terril Average
- ●USDA Zones 5a, averaged across Terril
- ●One soil character for all of Terril
- ●Frost dates read at Terril's scale: Apr 19 to Oct 16
YOUR Parcel
- ✓Your exact zone, not Terril's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Terril
Pull a site-specific report for your exact address in Terril, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Terril averages can't show:
We read public map data around Terril — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Terril average
How we know this about Terril
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 Terril’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 Terril
When does frost risk typically end in Terril?
The last hard freeze (28°F) in Terril typically lands around Apr 19, 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 10.
When is the first frost in Terril?
The first hard freeze (28°F) in Terril typically arrives around Oct 16, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 2, so the watching starts about Sep 16 — about 180 days after the spring freeze cleared.
How long is the growing season in Terril?
Measured between 28°F hard freezes, Terril sees about 180 frost-free days — roughly Apr 19 through Oct 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 10 to Oct 2, about 145 days.
Is the soil safe to grow vegetables in Terril?
The federal record around Terril is a meaningful one — 166 documented sites, mostly Underground Storage Tanks entries (103), the nearest Underground Storage Tanks record about 0.1 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.
How do I protect my plants from frost in Terril?
From about Sep 16 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 16 (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 16. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Terril's scale — its 5a band and its 180-day season. Your yard writes its own version of Terril'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 Terril’s own scale
6 of the readings below were taken at Terril's own scale — its own ~180-day season between 28°F freezes, the 348 acres it covers and 166 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Terril's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Terril's own 28°F hard-freeze dates, about Apr 19 and Oct 16 and the ~180-day span between themNOAA 1991–2020 Climate Normals
- 166 documented contamination sites on the federal record near Terril, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Terril's boundary and the 348 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~180-day seasonGrowable Ground crop-matching engine
- The ecoregion at Terril'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 Terril's 348 acres read through its county's SSURGO summaryfrom Dickinson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Dickinson 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 Dickinson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Terril's 348 acreswhy one lot differs from the next →
- Which side of Terril you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 348 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 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 Terril-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaTerril sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides