Milton, 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.
Growers here do well with cabbage, blueberry, lavender, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Milton, 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 Milton 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 Milton — soil, climate, flood, and parcel records. How we handle your address.
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Milton — the short answer
Milton, Iowa: USDA zone 5b, about 208 days between hard freezes, across 2K acres of city.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 30
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~208
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 2K 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 Milton's average, not your lot's — a low corner or a tree line moves it. Against Milton's 208-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Milton
Each reading below is measured for Milton itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMilton runs about 208 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredMilton 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 Milton is in
Milton sits in the Central Irregular Plains — EPA Level III, inside the wider Great Plains. That is read at Milton's own centroid rather than borrowed from Van Buren County.
What Grows in Milton
Every plant below cleared Milton's own zone 5b and its 208-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Milton?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Mar 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 30 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
What's on the federal record near Milton
Closest first, within ~10 miles of Milton. Listing isn't leaking, and distance isn't exposure.
- OIL CITY PLUSUnderground Storage Tanks · 300 ft
- 068N11W30ABBB 34981 1961Milton 2Nitrate · 1300 ft
- CITY MAINTENANCE BLDGUnderground Storage Tanks · 1400 ft
- MID-STATES MANUFACTURING AND ENGINEERING INCBrownfields · 1400 ft
- LEBANON STOREUnderground Storage Tanks · 2600 ft
- ITC MIDWEST - MILTONBrownfields · 0.5 mi
- CEDARS TRUCK STOPUnderground Storage Tanks · 0.8 mi
- 068N11W30D 40852 1967Milton 3Nitrate · 1.0 mi
- 068N11W30AACB 10282 1957MiltonNitrate · 1.0 mi
- 067N11W04CAB 00859 1938Nitrate · 3.1 mi
- 068N11W23ACAC 18562 1966Nitrate · 3.9 mi
- MID-AMERICA PIPELINE CO., LLC - CANTRIL STATIONBrownfields · 4.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Milton'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 Milton.
Total Sites
37
within ~10 miles of Milton
Risk Level
Low
Highest-severity
2 concentrated animal feeding operations
Sources Checked
within ~10 miles of Milton
Severity Distribution
within ~10 miles of Milton
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Milton, Nitrate runs higher than the national average — 18 sites within ~10 miles of Milton. That's not a problem with your land — it's information about 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 Milton
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 Milton average
Your land is one point inside Milton
Everything above resolves to Milton as a whole — one PHZM band and one 28°F frost record, read across 2K 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 Milton Average
Milton Average
- ●USDA Zones 5b, averaged across Milton
- ●One soil character for all of Milton
- ●Frost dates read at Milton's scale: Apr 5 to Oct 30
YOUR Parcel
- ✓Your exact zone, not Milton's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Milton
Pull a site-specific report for your exact address in Milton, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Milton averages can't show:
We read public map data around Milton — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Milton average
How we know this about Milton
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 Milton’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 Milton
When does frost risk typically end in Milton?
The last hard freeze (28°F) in Milton typically lands around Apr 5, 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 26.
When is the first frost in Milton?
The first hard freeze (28°F) in Milton typically arrives around Oct 30, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 16, so the watching starts about Sep 30 — about 208 days after the spring freeze cleared.
How long is the growing season in Milton?
Measured between 28°F hard freezes, Milton sees about 208 frost-free days — roughly Apr 5 through Oct 30, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 26 to Oct 16, about 173 days.
Is the soil safe to grow vegetables in Milton?
The federal record around Milton is light — 37 documented sites across the 9 federal source types we checked, mostly Nitrate entries (18), the nearest Underground Storage Tanks record under a tenth of a mile out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do I protect my plants from frost in Milton?
From about Sep 30 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 30 (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 30. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Milton's scale — its 5b band and its 208-day season. Your yard writes its own version of Milton'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 Milton’s own scale
6 of the readings below were taken at Milton's own scale — its own ~208-day season between 28°F freezes, the 1,723 acres it covers and 37 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Milton's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Milton's own 28°F hard-freeze dates, about Apr 5 and Oct 30 and the ~208-day span between themNOAA 1991–2020 Climate Normals
- 37 documented contamination sites on the federal record near Milton, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Milton's boundary and the 1,723 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~208-day seasonGrowable Ground crop-matching engine
- The ecoregion at Milton's own centroid, the Central Irregular PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Milton's 1,723 acres read through its county's SSURGO summaryfrom Van Buren County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Van Buren 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 Van Buren County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Milton's 1,723 acreswhy one lot differs from the next →
- Which side of Milton you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,723 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 Milton-wide figureread your own land →