Oakville, Iowa, sits in USDA hardiness zone 5b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Among the crops suited to this profile: cabbage, blueberry, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Oakville, 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 Oakville 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 Oakville — soil, climate, flood, and parcel records. How we handle your address.
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Oakville — the short answer
Oakville, Iowa: USDA zone 5b, about 215 days between hard freezes, across 267 acres of city.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 2
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 3
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~215
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 267 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 5b is Oakville's average, not your lot's — a low corner or a tree line moves it. Against Oakville's 215-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Oakville
Each reading below is measured for Oakville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredOakville runs about 215 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredOakville sits in USDA hardiness zone 5b.
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 Oakville is in
Oakville sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Oakville's own centroid rather than borrowed from Louisa County.
What Grows in Oakville
Every plant below cleared Oakville's own zone 5b and its 215-day season. Each card opens that plant's Iowa profile. How we score.
Is it too late to plant in Oakville?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Mar 5; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 2 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 3 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
What's on the federal record near Oakville
Closest first, within ~10 miles of Oakville. Listing isn't leaking, and distance isn't exposure.
- FORMER JMC TEXACOUnderground Storage Tanks · 300 ft
- 073N02W25BBCC 1973Oakville 1Nitrate · 450 ft
- TRI OAK FOODSUnderground Storage Tanks · 1200 ft
- TRIOAK FOODS INC - FEED MILLToxics Release Inventory · 1300 ft
- 073N02W11CABD 18353 1966Nitrate · 2.8 mi
- 073N02W33DCDD 14379 1963Nitrate · 2.9 mi
- 073N02W09CCCNitrate · 3.7 mi
- 073N02W09CAB 01657 1943Nitrate · 3.8 mi
- 072N02W14BABC 10743 1954Nitrate · 3.9 mi
- 072N02W08ADC 06911 1954Nitrate · 4.6 mi
- 074N01W31DCB 12527 1960US Army Corps of EngineersNitrate · 4.7 mi
- 072N02W08BBBB 08743 1957Nitrate · 5.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Oakville'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 Oakville.
Total Sites
117
within ~10 miles of Oakville
Risk Level
Moderate
Highest-severity
4 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Oakville
Severity Distribution
within ~10 miles of Oakville
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Oakville, Nitrate runs higher than the national average — 54 sites within ~10 miles of Oakville. That's not a problem with your land — it's information about 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 Oakville
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 Oakville average
Your land is one point inside Oakville
Everything above resolves to Oakville as a whole — one PHZM band and one 28°F frost record, read across 267 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 Oakville Average
Oakville Average
- ●USDA Zones 5b, averaged across Oakville
- ●One soil character for all of Oakville
- ●Frost dates read at Oakville's scale: Apr 2 to Nov 3
YOUR Parcel
- ✓Your exact zone, not Oakville's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Oakville
Pull a site-specific report for your exact address in Oakville, Iowa — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Oakville averages can't show:
We read public map data around Oakville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Oakville average
How we know this about Oakville
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 Oakville’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 Oakville
When does frost risk typically end in Oakville?
The last hard freeze (28°F) in Oakville typically lands around Apr 2, 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 Apr 23.
When is the first frost in Oakville?
The first hard freeze (28°F) in Oakville typically arrives around Nov 3, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 20, so the watching starts about Oct 4 — about 215 days after the spring freeze cleared.
How long is the growing season in Oakville?
Measured between 28°F hard freezes, Oakville sees about 215 frost-free days — roughly Apr 2 through Nov 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 23 to Oct 20, about 180 days.
Is the soil safe to grow vegetables in Oakville?
The federal record around Oakville shows 117 documented sites, mostly Nitrate entries (54), 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 Oakville?
From about Oct 4 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 Nov 3 (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 Nov 3. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Oakville's scale — its 5b band and its 215-day season. Your yard writes its own version of Oakville'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 Oakville’s own scale
6 of the readings below were taken at Oakville's own scale — its own ~215-day season between 28°F freezes, the 267 acres it covers and 117 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Oakville's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Oakville's own 28°F hard-freeze dates, about Apr 2 and Nov 3 and the ~215-day span between themNOAA 1991–2020 Climate Normals
- 117 documented contamination sites on the federal record near Oakville, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Oakville's boundary and the 267 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~215-day seasonGrowable Ground crop-matching engine
- The ecoregion at Oakville's own centroid, the Interior River Valleys and HillsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Oakville's 267 acres read through its county's SSURGO summaryfrom Louisa County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Louisa 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 Louisa County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Oakville's 267 acreswhy one lot differs from the next →
- Which side of Oakville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 267 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 Oakville-wide figureread your own land →