Oakville, California, sits in USDA hardiness zone 9b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Among the crops suited to this profile: okra, meyer lemon, california poppy, and artichoke. 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, California: USDA zone 9b, about 327 days between hard freezes, across 870 acres of town.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 23
- Napa County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 16
- Napa County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~327
- Napa County normal — NOAA 1991–2020, nearest to this town
- Town area
- 870 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are Napa County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9b is Oakville's average, not your lot's — a low corner or a tree line moves it. Against Oakville's 327-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
From county recordsOakville runs about 327 days between hard freezes (read from Napa County, the closest normal to Oakville) — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredOakville sits in USDA hardiness zone 9b.
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 Central California Foothills and Coastal Mountains — EPA Level III, inside the wider Mediterranean California. That is read at Oakville's own centroid rather than borrowed from Napa County.
What Grows in Oakville
Every plant below cleared Oakville's own zone 9b and its 327-day season. Each card opens that plant's California 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 Jan 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jan 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 16 — long-season crops need about 90 days of runway, quick greens only 30. Here the calendar nearly circles: cool-season crops take the winter shift, and the next window is always close.
What's on the federal record near Oakville
Closest first, within ~10 miles of Oakville. Listing isn't leaking, and distance isn't exposure.
- OAKVILLE PUMP SERVICE INCBrownfields · 1200 ft
- NAPA WINE COMPANYBrownfields · 1600 ft
- CONSTELLATION BRANDS US OPERATIONS INCBrownfields · 1600 ft
- NICKEL & NICKEL WINERYBrownfields · 1700 ft
- FN VITICULTURE, LLCBrownfields · 1700 ft
- OPUS ONE WINERYBrownfields · 2300 ft
- ROBERT MONDAVI WINERYToxics Release Inventory · 2300 ft
- ROBERT MONDAVI WINERYBrownfields · 2300 ft
- SWANSON VINEYARD & WINERYBrownfields · 0.8 mi
- CALTRANS DIST 4Brownfields · 0.8 mi
- PACIFIC BELLBrownfields · 0.8 mi
- TITAN COBrownfields · 0.8 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
441
within ~10 miles of Oakville
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
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, two things run higher than the national average within ~10 miles of Oakville — Brownfields (309 sites) and Mining (31 sites). That's not a problem with your land — it's information about it.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
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, read across 870 acres, with hard-freeze dates borrowed from Napa County’s record because no 30-year normal resolves at this town’s own centroid. 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 Oakville Average
Oakville Average
- ●USDA Zones 9b, averaged across Oakville
- ●One soil character for all of Oakville
- ●Frost dates read at Oakville's scale: Jan 23 to Dec 16
YOUR Parcel
- ✓Your exact zone, not Oakville's 9b
- ✓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, California — 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 town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Napa County’s record, because none resolves here; 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 Oakville
When does frost risk typically end in Oakville?
The last hard freeze (28°F) in Oakville typically lands around Jan 23, 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 Feb 13.
When is the first frost in Oakville?
The first hard freeze (28°F) in Oakville typically arrives around Dec 16, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Dec 2, so the watching starts about Nov 16 — about 327 days after the spring freeze cleared.
How long is the growing season in Oakville?
Measured between 28°F hard freezes, Oakville sees about 327 frost-free days — roughly Jan 23 through Dec 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 13 to Dec 2, about 292 days.
Is the soil safe to grow vegetables in Oakville?
The federal record around Oakville is a meaningful one — 441 documented sites, mostly Brownfields entries (309), the nearest Brownfields record about 0.2 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 Oakville?
From about Nov 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 Dec 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 Dec 16. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Oakville's scale — its 9b band and its 327-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
5 of the readings below were taken at Oakville's own scale — the 870 acres it covers and 441 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Oakville's own USDA hardiness band, zones 9bUSDA PHZM 2023
- 441 documented contamination sites on the federal record near Oakville, the closest Brownfields record about 0.2 miles out from the town centreFederal environmental registers
- Oakville's boundary and the 870 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~327-day seasonGrowable Ground crop-matching engine
- The ecoregion at Oakville's own centroid, the Central California Foothills and Coastal MountainsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Oakville has no normal of its own, so its county's is the closest measured readfrom Napa County
- Soil character — no town-scale survey exists, so Oakville's 870 acres read through its county's SSURGO summaryfrom Napa County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Napa County
- The growing challenges every California grower plans around — written at state scale, so they stay on the state guidefrom California
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Napa County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Oakville's 870 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 870 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.2 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 Oakville-wide figureread your own land →
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