Gray, Iowa, sits in USDA hardiness zone 5a — a zone band wide enough that plant choice, not possibility, is the interesting question.
These conditions suit cabbage, cranberry, lavender, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Gray, 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 Gray 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 Gray — soil, climate, flood, and parcel records. How we handle your address.
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Gray — the short answer
Gray, Iowa: USDA zone 5a, about 188 days between hard freezes, across 637 acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 14
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 19
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~188
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 637 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 Gray's average, not your lot's — a low corner or a tree line moves it. Against Gray's 188-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Gray
Each reading below is measured for Gray itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGray runs about 188 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
MeasuredGray 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 Gray is in
Gray sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Gray's own centroid rather than borrowed from Audubon County.
What Grows in Gray
Every plant below cleared Gray's own zone 5a and its 188-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Gray?
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 17; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 14 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 19 — 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 Gray
Closest first, within ~10 miles of Gray. Listing isn't leaking, and distance isn't exposure.
- 081N36W12DBBA 14964 1961Gray 2Nitrate · 650 ft
- EARL STEFFESUnderground Storage Tanks · 1100 ft
- AUDUBON COMM SCHOOLUnderground Storage Tanks · 1400 ft
- KENDLE OIL COUnderground Storage Tanks · 1400 ft
- 081N36W12CBCA 26351 1981IGS & USGS WC-18Nitrate · 2400 ft
- 082N35W17CDBA 1952Templeton 2Nitrate · 5.0 mi
- AUD-EX FEED SERVICE COUnderground Storage Tanks · 5.3 mi
- PUCK IMPLEMENT COMPANYUnderground Storage Tanks · 5.3 mi
- AGRILAND FS INCUnderground Storage Tanks · 5.3 mi
- KUM & GO #232Underground Storage Tanks · 5.3 mi
- AUDUBON TRACTOR PARTSUnderground Storage Tanks · 5.3 mi
- MANNING COMMUNITY SCHOOLBrownfields · 5.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Gray'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 Gray.
Total Sites
128
within ~10 miles of Gray
Risk Level
Moderate
Highest-severity
6 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Gray
Severity Distribution
within ~10 miles of Gray
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Gray, Nitrate runs higher than the national average — 68 sites within ~10 miles of Gray. 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 Gray
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 Gray average
Your land is one point inside Gray
Everything above resolves to Gray as a whole — one PHZM band and one 28°F frost record, read across 637 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 Gray Average
Gray Average
- ●USDA Zones 5a, averaged across Gray
- ●One soil character for all of Gray
- ●Frost dates read at Gray's scale: Apr 14 to Oct 19
YOUR Parcel
- ✓Your exact zone, not Gray's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Gray
Pull a site-specific report for your exact address in Gray, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Gray averages can't show:
We read public map data around Gray — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Gray average
How we know this about Gray
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 Gray’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 Gray
When does frost risk typically end in Gray?
The last hard freeze (28°F) in Gray typically lands around Apr 14, 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 5.
When is the first frost in Gray?
The first hard freeze (28°F) in Gray typically arrives around Oct 19, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 5, so the watching starts about Sep 19 — about 188 days after the spring freeze cleared.
How long is the growing season in Gray?
Measured between 28°F hard freezes, Gray sees about 188 frost-free days — roughly Apr 14 through Oct 19, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 5 to Oct 5, about 153 days.
Is the soil safe to grow vegetables in Gray?
The federal record around Gray shows 128 documented sites, mostly Nitrate entries (68), the nearest Nitrate record about 0.1 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 Gray?
From about Sep 19 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 19 (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 19. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Gray's scale — its 5a band and its 188-day season. Your yard writes its own version of Gray'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 Gray’s own scale
6 of the readings below were taken at Gray's own scale — its own ~188-day season between 28°F freezes, the 637 acres it covers and 128 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Gray's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Gray's own 28°F hard-freeze dates, about Apr 14 and Oct 19 and the ~188-day span between themNOAA 1991–2020 Climate Normals
- 128 documented contamination sites on the federal record near Gray, the closest Nitrate record about 0.1 miles out from the town centreFederal environmental registers
- Gray's boundary and the 637 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~188-day seasonGrowable Ground crop-matching engine
- The ecoregion at Gray'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 Gray's 637 acres read through its county's SSURGO summaryfrom Audubon County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Audubon 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 Audubon County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Gray's 637 acreswhy one lot differs from the next →
- Which side of Gray you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 637 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate 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 Gray-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaGray sits outside our named growing regions, so Iowa as a whole is its closest context here.