South Amana, Iowa, sits in USDA hardiness zone 5a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
On paper, cabbage, cranberry, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in South Amana, 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 South Amana 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 South Amana — soil, climate, flood, and parcel records. How we handle your address.
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South Amana — the short answer
South Amana, Iowa: USDA zone 5a, about 188 days between hard freezes, across 890 acres of town.
- 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 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~188
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 890 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 South Amana's average, not your lot's — a low corner or a tree line moves it. Against South Amana's 188-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in South Amana
Each reading below is measured for South Amana itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSouth Amana 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
MeasuredSouth Amana 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 South Amana is in
South Amana sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at South Amana's own centroid rather than borrowed from Iowa County.
What Grows in South Amana
Every plant below cleared South Amana'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 South Amana?
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 20 — 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 South Amana
Closest first, within ~10 miles of South Amana. Listing isn't leaking, and distance isn't exposure.
- 081N10W36CCCC 02092 1945South Amana (13) 12Nitrate · 1800 ft
- FLOYD''S REPAIRUnderground Storage Tanks · 1900 ft
- 081N10W35DAAD 1979South Amana (12) 120Nitrate · 1900 ft
- 080N10W01BBBA 20253 1968South Amana 1Nitrate · 2000 ft
- 080N10W01BBB South AmanaNitrate · 2300 ft
- 081N10W36CCCC 06371 1953South Amana 12Nitrate · 0.5 mi
- 081N10W36CCCC 00971 1939South Amana 2Nitrate · 0.5 mi
- AMANA SOCIETYUnderground Storage Tanks · 0.6 mi
- KRAUSS FURNITURE SHOPUnderground Storage Tanks · 0.6 mi
- 081N09W30BBAB 1969High Amana 10Nitrate · 2.4 mi
- A-42 AMANA FARMS INC.Toxics Release Inventory · 2.4 mi
- 081N10W24CCAC 1954West Amana 11Nitrate · 2.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from South Amana'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 South Amana.
Total Sites
251
within ~10 miles of South Amana
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of South Amana
Severity Distribution
within ~10 miles of South Amana
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around South Amana, Nitrate runs higher than the national average — 142 sites within ~10 miles of South Amana. 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 South Amana
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 South Amana average
Your land is one point inside South Amana
Everything above resolves to South Amana as a whole — one PHZM band and one 28°F frost record, read across 890 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 South Amana Average
South Amana Average
- ●USDA Zones 5a, averaged across South Amana
- ●One soil character for all of South Amana
- ●Frost dates read at South Amana's scale: Apr 15 to Oct 20
YOUR Parcel
- ✓Your exact zone, not South Amana's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in South Amana
Pull a site-specific report for your exact address in South Amana, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that South Amana averages can't show:
We read public map data around South Amana — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the South Amana average
How we know this about South Amana
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 South Amana’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 South Amana
When does frost risk typically end in South Amana?
The last hard freeze (28°F) in South Amana 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 South Amana?
The first hard freeze (28°F) in South Amana typically arrives around Oct 20, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 6, so the watching starts about Sep 20 — about 188 days after the spring freeze cleared.
How long is the growing season in South Amana?
Measured between 28°F hard freezes, South Amana sees about 188 frost-free days — roughly Apr 15 through Oct 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 6 to Oct 6, about 153 days.
Is the soil safe to grow vegetables in South Amana?
The federal record around South Amana is a meaningful one — 251 documented sites, mostly Nitrate entries (142), the nearest Nitrate record about 0.3 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in South Amana?
From about Sep 20 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 20 (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 20. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at South Amana's scale — its 5a band and its 188-day season. Your yard writes its own version of South Amana'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 South Amana’s own scale
6 of the readings below were taken at South Amana's own scale — its own ~188-day season between 28°F freezes, the 890 acres it covers and 251 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- South Amana's own USDA hardiness band, zones 5aUSDA PHZM 2023
- South Amana's own 28°F hard-freeze dates, about Apr 15 and Oct 20 and the ~188-day span between themNOAA 1991–2020 Climate Normals
- 251 documented contamination sites on the federal record near South Amana, the closest Nitrate record about 0.3 miles out from the town centreFederal environmental registers
- South Amana's boundary and the 890 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 South Amana'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 South Amana's 890 acres read through its county's SSURGO summaryfrom Iowa County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Iowa 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 Iowa County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among South Amana's 890 acreswhy one lot differs from the next →
- Which side of South Amana you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 890 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.3 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 South Amana-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaSouth Amana sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides