Center Junction, Iowa, sits in USDA hardiness zone 5a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
The conditions favor cabbage, cranberry, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Center 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 Center 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 Center Junction — soil, climate, flood, and parcel records. How we handle your address.
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Center Junction — the short answer
Center Junction, Iowa: USDA zone 5a, about 184 days between hard freezes, across 470 acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 18
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~184
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 470 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 Center Junction's average, not your lot's — a low corner or a tree line moves it. Against Center Junction's 184-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Center Junction
Each reading below is measured for Center Junction itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredCenter Junction runs about 184 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
MeasuredCenter 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 Center Junction is in
Center Junction sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Center Junction's own centroid rather than borrowed from Jones County.
What Grows in Center Junction
Every plant below cleared Center Junction's own zone 5a and its 184-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Center Junction?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 20; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 17 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 18 — 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 Center Junction
Closest first, within ~10 miles of Center Junction. Listing isn't leaking, and distance isn't exposure.
- JONES COUNTY PROPERTYUnderground Storage Tanks · 500 ft
- 084N02W04CBB Center JuntionNitrate · 700 ft
- KENTS D-XUnderground Storage Tanks · 1200 ft
- 084N02W04CACC 00218 1939Center Junction 1Nitrate · 1300 ft
- ITC MIDWEST - WYOMINGBrownfields · 2.3 mi
- JONES COUNTY SOLID WASTEToxics Release Inventory · 2.6 mi
- WELTY TRUCK LINESUnderground Storage Tanks · 3.8 mi
- MIDLAND COMMUNITY SCHOOLUnderground Storage Tanks · 3.8 mi
- TAYLOR D-XUnderground Storage Tanks · 3.9 mi
- 084N01W07BBBC 34653 1913Onslow 1Nitrate · 4.0 mi
- BALSTER IMPLEMENT AND PARTS COUnderground Storage Tanks · 4.0 mi
- Balster''s Implement and Parts CompanyUnderground Storage Tanks · 4.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Center 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 Center Junction.
Total Sites
126
within ~10 miles of Center Junction
Risk Level
Moderate
Highest-severity
4 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Center Junction
Severity Distribution
within ~10 miles of Center Junction
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
Check your specific parcel in Center 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 Center Junction average
Your land is one point inside Center Junction
Everything above resolves to Center Junction as a whole — one PHZM band and one 28°F frost record, read across 470 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 town 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 Center Junction Average
Center Junction Average
- ●USDA Zones 5a, averaged across Center Junction
- ●One soil character for all of Center Junction
- ●Frost dates read at Center Junction's scale: Apr 17 to Oct 18
YOUR Parcel
- ✓Your exact zone, not Center Junction's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Center Junction
Pull a site-specific report for your exact address in Center Junction, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Center Junction averages can't show:
We read public map data around Center Junction — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Center Junction average
How we know this about Center Junction
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Center 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 town grain anywhere on this page — there is no town-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 Center Junction
When does frost risk typically end in Center Junction?
The last hard freeze (28°F) in Center Junction typically lands around Apr 17, 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 8.
When is the first frost in Center Junction?
The first hard freeze (28°F) in Center Junction typically arrives around Oct 18, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 4, so the watching starts about Sep 18 — about 184 days after the spring freeze cleared.
How long is the growing season in Center Junction?
Measured between 28°F hard freezes, Center Junction sees about 184 frost-free days — roughly Apr 17 through Oct 18, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 8 to Oct 4, about 149 days.
Is the soil safe to grow vegetables in Center Junction?
The federal record around Center Junction shows 126 documented sites, mostly Underground Storage Tanks entries (73), the nearest Underground Storage Tanks record under a tenth of a mile 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 Center Junction?
From about Sep 18 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 18 (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 18. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Center Junction's scale — its 5a band and its 184-day season. Your yard writes its own version of Center 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 Center Junction’s own scale
6 of the readings below were taken at Center Junction's own scale — its own ~184-day season between 28°F freezes, the 470 acres it covers and 126 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Center Junction's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Center Junction's own 28°F hard-freeze dates, about Apr 17 and Oct 18 and the ~184-day span between themNOAA 1991–2020 Climate Normals
- 126 documented contamination sites on the federal record near Center Junction, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Center Junction's boundary and the 470 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~184-day seasonGrowable Ground crop-matching engine
- The ecoregion at Center 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 Center Junction's 470 acres read through its county's SSURGO summaryfrom Jones County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Jones 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 Jones County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Center Junction's 470 acreswhy one lot differs from the next →
- Which side of Center 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 470 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 Center Junction-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaCenter Junction sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides