Jewell Junction, Iowa, sits in USDA hardiness zone 5a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
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 Jewell Junction, 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 Jewell Junction 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 Jewell Junction — soil, climate, flood, and parcel records. How we handle your address.
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Jewell Junction — the short answer
Jewell Junction, Iowa: USDA zone 5a, about 187 days between hard freezes, across 2K acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 15
- 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
- ~187
- 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 5a is Jewell Junction's average, not your lot's — a low corner or a tree line moves it. Against Jewell Junction's 187-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Jewell Junction
Each reading below is measured for Jewell Junction itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredJewell Junction runs about 187 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
MeasuredJewell Junction 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 Jewell Junction is in
Jewell Junction sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Jewell Junction's own centroid rather than borrowed from Hamilton County.
What Grows in Jewell Junction
Every plant below cleared Jewell Junction's own zone 5a and its 187-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Jewell Junction?
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 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 15 (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. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Jewell Junction
Closest first, within ~10 miles of Jewell Junction. Listing isn't leaking, and distance isn't exposure.
- FARM BUREAUUnderground Storage Tanks · 750 ft
- CENTRAL IOWA COOPUnderground Storage Tanks · 1400 ft
- 087N24W34BBC 05758 1951Jewell 2Nitrate · 1400 ft
- 087N24W34BBCC 40480 1932Jewell 1Nitrate · 1400 ft
- DANS 66Underground Storage Tanks · 1700 ft
- COUNTRY CORNER CONVENIENCE STOUnderground Storage Tanks · 1800 ft
- CITY OF JEWELLUnderground Storage Tanks · 2100 ft
- HAMILTON COUNTY MAINTENANCE SHEDUnderground Storage Tanks · 0.6 mi
- CASEY''S GENERAL STORE 2300Underground Storage Tanks · 0.6 mi
- SOUTH HAMILTON SCHOOLUnderground Storage Tanks · 0.6 mi
- NORTHGATE D-XUnderground Storage Tanks · 0.9 mi
- ITC MIDWEST - LYONS TOWNSHIPBrownfields · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Jewell Junction'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 Jewell Junction.
Total Sites
113
within ~10 miles of Jewell Junction
Risk Level
Moderate
Highest-severity
7 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Jewell Junction
Severity Distribution
within ~10 miles of Jewell Junction
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Jewell Junction, Toxics Release Inventory runs higher than the national average — 7 sites within ~10 miles of Jewell Junction. That's not a problem with your land — it's information about it.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Jewell Junction
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 Jewell Junction average
Your land is one point inside Jewell Junction
Everything above resolves to Jewell Junction 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 Jewell Junction Average
Jewell Junction Average
- ●USDA Zones 5a, averaged across Jewell Junction
- ●One soil character for all of Jewell Junction
- ●Frost dates read at Jewell Junction's scale: Apr 15 to Oct 19
YOUR Parcel
- ✓Your exact zone, not Jewell Junction's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Jewell Junction
Pull a site-specific report for your exact address in Jewell Junction, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Jewell Junction averages can't show:
We read public map data around Jewell Junction — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Jewell Junction average
How we know this about Jewell Junction
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 Jewell Junction’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 Jewell Junction
When does frost risk typically end in Jewell Junction?
The last hard freeze (28°F) in Jewell Junction typically lands around Apr 15, 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 6.
When is the first frost in Jewell Junction?
The first hard freeze (28°F) in Jewell Junction 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 187 days after the spring freeze cleared.
How long is the growing season in Jewell Junction?
Measured between 28°F hard freezes, Jewell Junction sees about 187 frost-free days — roughly Apr 15 through Oct 19, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 6 to Oct 5, about 152 days.
Is the soil safe to grow vegetables in Jewell Junction?
The federal record around Jewell Junction shows 113 documented sites, mostly Underground Storage Tanks entries (63), the nearest Underground Storage Tanks 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 Jewell Junction?
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 Jewell Junction's scale — its 5a band and its 187-day season. Your yard writes its own version of Jewell Junction'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 Jewell Junction’s own scale
6 of the readings below were taken at Jewell Junction's own scale — its own ~187-day season between 28°F freezes, the 2,477 acres it covers and 113 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Jewell Junction's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Jewell Junction's own 28°F hard-freeze dates, about Apr 15 and Oct 19 and the ~187-day span between themNOAA 1991–2020 Climate Normals
- 113 documented contamination sites on the federal record near Jewell Junction, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Jewell Junction's boundary and the 2,477 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~187-day seasonGrowable Ground crop-matching engine
- The ecoregion at Jewell Junction'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 Jewell Junction's 2,477 acres read through its county's SSURGO summaryfrom Hamilton County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Hamilton 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 Hamilton County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Jewell Junction's 2,477 acreswhy one lot differs from the next →
- Which side of Jewell Junction you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 2,477 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 Jewell Junction-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaJewell Junction sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides