Jackson Junction, Iowa, sits in USDA hardiness zone 5a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Among the crops suited to this profile: cabbage, cranberry, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Jackson 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 Jackson 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 Jackson Junction — soil, climate, flood, and parcel records. How we handle your address.
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Jackson Junction — the short answer
Jackson Junction, Iowa: USDA zone 5a, about 181 days between hard freezes, across 4K acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 18
- 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
- ~181
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 4K 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 Jackson Junction's average, not your lot's — a low corner or a tree line moves it. Against Jackson Junction's 181-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Jackson Junction
Each reading below is measured for Jackson Junction itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredJackson Junction runs about 181 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
MeasuredJackson 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 Jackson Junction is in
Jackson Junction sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Jackson Junction's own centroid, and it is not what its county reads: Winneshiek County is mostly Driftless Area. The wider page above you is answering a different question about different ground.
What Grows in Jackson Junction
Every plant below cleared Jackson Junction's own zone 5a and its 181-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Jackson Junction?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 21; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 18 (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. 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 Jackson Junction
Closest first, within ~10 miles of Jackson Junction. Listing isn't leaking, and distance isn't exposure.
- TURKEY VALLEY COMMUNITY SCHOOLUnderground Storage Tanks · 1.1 mi
- SCHMITT FERTILIZER CORPUnderground Storage Tanks · 1.2 mi
- TURKEY VALLEY COMM SCHOOLUnderground Storage Tanks · 1.5 mi
- LYNCH L/S INCUnderground Storage Tanks · 2.9 mi
- 095N10W09CABD 1978Waucoma 1Nitrate · 3.0 mi
- M & M CONVENIENCE STOREUnderground Storage Tanks · 3.2 mi
- THE LITTLE STATIONUnderground Storage Tanks · 3.2 mi
- FAYETTE COUNTY ENGINEERUnderground Storage Tanks · 3.2 mi
- FORMER LAWLER OILUnderground Storage Tanks · 3.5 mi
- 095N10W16BCDA 19577 1965Nitrate · 3.8 mi
- FARMERS COOP PRODUCE COUnderground Storage Tanks · 4.2 mi
- HOMELAND ENERGY SOLUTIONS, LLCToxics Release Inventory · 5.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Jackson 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 Jackson Junction.
Total Sites
54
within ~10 miles of Jackson Junction
Risk Level
Moderate
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Jackson Junction
Severity Distribution
within ~10 miles of Jackson Junction
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Jackson Junction, Nitrate runs higher than the national average — 18 sites within ~10 miles of Jackson Junction. 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 Jackson 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 Jackson Junction average
Your land is one point inside Jackson Junction
Everything above resolves to Jackson Junction as a whole — one PHZM band and one 28°F frost record, read across 4K 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 Jackson Junction Average
Jackson Junction Average
- ●USDA Zones 5a, averaged across Jackson Junction
- ●One soil character for all of Jackson Junction
- ●Frost dates read at Jackson Junction's scale: Apr 18 to Oct 16
YOUR Parcel
- ✓Your exact zone, not Jackson Junction's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Jackson Junction
Pull a site-specific report for your exact address in Jackson Junction, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Jackson Junction averages can't show:
We read public map data around Jackson Junction — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Jackson Junction average
How we know this about Jackson 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 Jackson 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 Jackson Junction
When does frost risk typically end in Jackson Junction?
The last hard freeze (28°F) in Jackson Junction typically lands around Apr 18, 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 9.
When is the first frost in Jackson Junction?
The first hard freeze (28°F) in Jackson Junction 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 181 days after the spring freeze cleared.
How long is the growing season in Jackson Junction?
Measured between 28°F hard freezes, Jackson Junction sees about 181 frost-free days — roughly Apr 18 through Oct 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 9 to Oct 2, about 146 days.
Is the soil safe to grow vegetables in Jackson Junction?
The federal record around Jackson Junction shows 54 documented sites, mostly Underground Storage Tanks entries (30), the nearest Underground Storage Tanks record about 1.1 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 Jackson Junction?
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 Jackson Junction's scale — its 5a band and its 181-day season. Your yard writes its own version of Jackson 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 Jackson Junction’s own scale
6 of the readings below were taken at Jackson Junction's own scale — its own ~181-day season between 28°F freezes, the 3,812 acres it covers and 54 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Jackson Junction's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Jackson Junction's own 28°F hard-freeze dates, about Apr 18 and Oct 16 and the ~181-day span between themNOAA 1991–2020 Climate Normals
- 54 documented contamination sites on the federal record near Jackson Junction, the closest Underground Storage Tanks record about 1.1 miles out from the town centreFederal environmental registers
- Jackson Junction's boundary and the 3,812 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~181-day seasonGrowable Ground crop-matching engine
- Jackson Junction sits in the Western Corn Belt Plains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Jackson Junction's 3,812 acres read through its county's SSURGO summaryfrom Winneshiek County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Winneshiek 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 Winneshiek County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Jackson Junction's 3,812 acreswhy one lot differs from the next →
- Which side of Jackson 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 3,812 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 1.1 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 Jackson Junction-wide figureread your own land →
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