Boonville, California, sits in USDA hardiness zone 9b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Reliable performers under these conditions include tomato, artichoke, fig, and california poppy; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Boonville, 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 Boonville 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 Boonville — soil, climate, flood, and parcel records. How we handle your address.
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Boonville — the short answer
Boonville, California: USDA zone 9b, about 304 days between hard freezes, across 4K acres of town.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 5
- Mendocino County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 6
- Mendocino County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~304
- Mendocino County normal — NOAA 1991–2020, nearest to this town
- Town area
- 4K 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 Mendocino County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9b is Boonville's average, not your lot's — a low corner or a tree line moves it. Against Boonville's 304-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Boonville
Each reading below is measured for Boonville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsBoonville runs about 304 days between hard freezes (read from Mendocino County, the closest normal to Boonville) — 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
MeasuredBoonville 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 Boonville is in
Boonville sits in the Central California Foothills and Coastal Mountains — EPA Level III, inside the wider Mediterranean California. That is read at Boonville's own centroid, and it is not what its county reads: Mendocino County is mostly Klamath Mountains/California High North Coast Range. The wider page above you is answering a different question about different ground.
What Grows in Boonville
Plants matched to Boonville's USDA zones 9b, ordered by how much hardiness margin each has here — the ones with room to spare at both ends of this town's band lead. Each links to its full growing profile.
Is it too late to plant in Boonville?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Jan 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 6 — long-season crops need about 90 days of runway, quick greens only 30. In a climate this gentle, “too late” hardly applies — the question becomes which crops prefer the cooler months ahead.
What's on the federal record near Boonville
Closest first, within ~10 miles of Boonville. Listing isn't leaking, and distance isn't exposure.
- 013N014W02L001MNitrate · 700 ft
- Redwood Drive InUnderground Storage Tanks · 1300 ft
- REDWOOD DRIVE INN INCBrownfields · 1400 ft
- HIATT LOGGING INCBrownfields · 1700 ft
- CAL TRANS BOONVILLE MSBrownfields · 2300 ft
- PACIFIC BELLBrownfields · 0.6 mi
- TITUS LAND CONSTRUCTIONBrownfields · 0.8 mi
- ROBERT PARDINI LOGGINGBrownfields · 0.8 mi
- MENDOCINO SOLID WASTE MANAGEMENT AUTHORITYBrownfields · 0.9 mi
- ANDERSON VINEYARDS INCBrownfields · 0.9 mi
- ANDERSON VALLEY UNIFIED SCHOOL DISTRICTBrownfields · 1.4 mi
- NEW CINGULAR WIRELESS PCS LLCBrownfields · 2.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Boonville'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 Boonville.
Sources Checked
within ~10 miles of Boonville
Severity Distribution
within ~10 miles of Boonville
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Boonville, two things run higher than the national average within ~10 miles of Boonville — Mining (7 sites) and Brownfields (21 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in Boonville
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 Boonville average
Your land is one point inside Boonville
Everything above resolves to Boonville as a whole — one PHZM band, read across 4K acres, with hard-freeze dates borrowed from Mendocino 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 Boonville Average
Boonville Average
- ●USDA Zones 9b, averaged across Boonville
- ●One soil character for all of Boonville
- ●Frost dates read at Boonville's scale: Feb 5 to Dec 6
YOUR Parcel
- ✓Your exact zone, not Boonville's 9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Boonville
Pull a site-specific report for your exact address in Boonville, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Boonville averages can't show:
We read public map data around Boonville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Boonville average
How we know this about Boonville
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 Mendocino 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 Boonville
When does frost risk typically end in Boonville?
The last hard freeze (28°F) in Boonville typically lands around Feb 5, 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 26.
When is the first frost in Boonville?
The first hard freeze (28°F) in Boonville typically arrives around Dec 6, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 22, so the watching starts about Nov 6 — about 304 days after the spring freeze cleared.
How long is the growing season in Boonville?
Measured between 28°F hard freezes, Boonville sees about 304 frost-free days — roughly Feb 5 through Dec 6, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 26 to Nov 22, about 269 days.
Is the soil safe to grow vegetables in Boonville?
The federal record around Boonville shows 32 documented sites, mostly Brownfields entries (21), the nearest Nitrate record about 0.1 miles 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 Boonville?
From about Nov 6 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 6 (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 6. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Boonville's scale — its 9b band and its 304-day season. Your yard writes its own version of Boonville'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 Boonville’s own scale
4 of the readings below were taken at Boonville's own scale — the 3,548 acres it covers and 32 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- Boonville's own USDA hardiness band, zones 9bUSDA PHZM 2023
- 32 documented contamination sites on the federal record near Boonville, the closest Nitrate record about 0.1 miles out from the town centreFederal environmental registers
- Boonville's boundary and the 3,548 acres inside itUS Census TIGER/Line 2025
- Boonville sits in the Central California Foothills and Coastal Mountains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Boonville has no normal of its own, so its county's is the closest measured readfrom Mendocino County
- Soil character — no town-scale survey exists, so Boonville's 3,548 acres read through its county's SSURGO summaryfrom Mendocino County
- The candidate plant list — California's curated set, filtered to this zone band and re-ordered by how much margin each has herefrom California
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Mendocino 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 Mendocino County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Boonville's 3,548 acreswhy one lot differs from the next →
- Which side of Boonville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,548 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.1 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 Boonville-wide figureread your own land →