Tripoli, 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.
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 Tripoli, 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 Tripoli 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 Tripoli — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Tripoli — the short answer
Tripoli, Iowa: USDA zone 5a, about 184 days between hard freezes, across 891 acres of city.
- 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
- City area
- 891 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 Tripoli's average, not your lot's — a low corner or a tree line moves it. Against Tripoli's 184-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Tripoli
Each reading below is measured for Tripoli itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredTripoli 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
MeasuredTripoli 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 Tripoli is in
Tripoli sits in the Western Corn Belt Plains — EPA Level III, inside the wider Great Plains. That is read at Tripoli's own centroid rather than borrowed from Bremer County.
What Grows in Tripoli
Every plant below cleared Tripoli'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 Tripoli?
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 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 Tripoli
Closest first, within ~10 miles of Tripoli. Listing isn't leaking, and distance isn't exposure.
- BUHR CHEVROLET-BUICKBrownfields · 250 ft
- FIGANBAUM GRAIN, INCBrownfields · 300 ft
- KEVINS AUTO REPAIRUnderground Storage Tanks · 400 ft
- GUPPYS ON THE GOUnderground Storage Tanks · 400 ft
- TONNE SERVICE STATIONUnderground Storage Tanks · 400 ft
- BREMER COUNTY HIGHWAY DEPTUnderground Storage Tanks · 900 ft
- CEDAR VALLEY F SUnderground Storage Tanks · 1000 ft
- 092N12W04AADD 04694 1950Tripoli 2Nitrate · 1000 ft
- DICK'S TRUCK SHOPBrownfields · 1200 ft
- DICK'S PETROLEUMBrownfields · 1500 ft
- BREMER COUNTY CONSERVATION BOARDUnderground Storage Tanks · 1600 ft
- FIGANBAUM TRUCKING INCUnderground Storage Tanks · 1800 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Tripoli'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 Tripoli.
Total Sites
88
within ~10 miles of Tripoli
Risk Level
Moderate
Highest-severity
2 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Tripoli
Severity Distribution
within ~10 miles of Tripoli
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Tripoli, Nitrate runs higher than the national average — 28 sites within ~10 miles of Tripoli. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around 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 Tripoli
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 Tripoli average
Your land is one point inside Tripoli
Everything above resolves to Tripoli as a whole — one PHZM band and one 28°F frost record, read across 891 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 Tripoli Average
Tripoli Average
- ●USDA Zones 5a, averaged across Tripoli
- ●One soil character for all of Tripoli
- ●Frost dates read at Tripoli's scale: Apr 17 to Oct 18
YOUR Parcel
- ✓Your exact zone, not Tripoli's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Tripoli
Pull a site-specific report for your exact address in Tripoli, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Tripoli averages can't show:
We read public map data around Tripoli — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Tripoli average
How we know this about Tripoli
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 Tripoli’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 Tripoli
When does frost risk typically end in Tripoli?
The last hard freeze (28°F) in Tripoli 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 Tripoli?
The first hard freeze (28°F) in Tripoli 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 Tripoli?
Measured between 28°F hard freezes, Tripoli 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 Tripoli?
The federal record around Tripoli shows 88 documented sites, mostly Underground Storage Tanks entries (47), the nearest Brownfields 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 Tripoli?
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 Tripoli's scale — its 5a band and its 184-day season. Your yard writes its own version of Tripoli'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 Tripoli’s own scale
6 of the readings below were taken at Tripoli's own scale — its own ~184-day season between 28°F freezes, the 891 acres it covers and 88 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Tripoli's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Tripoli's own 28°F hard-freeze dates, about Apr 17 and Oct 18 and the ~184-day span between themNOAA 1991–2020 Climate Normals
- 88 documented contamination sites on the federal record near Tripoli, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Tripoli's boundary and the 891 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 Tripoli'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 Tripoli's 891 acres read through its county's SSURGO summaryfrom Bremer County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Bremer 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 Bremer County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Tripoli's 891 acreswhy one lot differs from the next →
- Which side of Tripoli you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 891 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Tripoli-wide figureread your own land →
More in Iowa
Wider growing context
What grows across IowaTripoli sits outside our named growing regions, so Iowa as a whole is its closest context here.
Nearby growing guides