Bonsall, California, sits in USDA hardiness zone 10a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
The conditions favor okra, meyer lemon, california poppy, and artichoke, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Bonsall, 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 Bonsall 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 Bonsall — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Bonsall — the short answer
Bonsall, California: USDA zone 10a, about 311 days between hard freezes, across 9K acres of town.
- USDA zone
- 10a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 3
- San Diego County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 11
- San Diego County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~311
- San Diego County normal — NOAA 1991–2020, nearest to this town
- Town area
- 9K 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 San Diego County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 10a is Bonsall's average, not your lot's — a low corner or a tree line moves it. Against Bonsall's 311-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Bonsall
Each reading below is measured for Bonsall itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsBonsall runs about 311 days between hard freezes (read from San Diego County, the closest normal to Bonsall) — 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
MeasuredBonsall sits in USDA hardiness zone 10a.
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 Bonsall is in
Bonsall sits in the Southern California/Northern Baja Coast — EPA Level III, inside the wider Mediterranean California. That is read at Bonsall's own centroid rather than borrowed from San Diego County.
What Grows in Bonsall
Every plant below cleared Bonsall's own zone 10a and its 311-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in Bonsall?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Jan 6; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 3 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 11 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.
Documented around Bonsall
Spotted lanternfly documented 8 miles from Bonsall, first recorded 2022. What to watch for.
What's on the federal record near Bonsall
Closest first, within ~10 miles of Bonsall. Listing isn't leaking, and distance isn't exposure.
- MOODY CREEK FARMS LLCBrownfields · 2300 ft
- BROOKSIDE FARMSBrownfields · 0.6 mi
- SLR FARMSBrownfields · 0.9 mi
- Camino del Rey LLC-HMDUnderground Storage Tanks · 0.9 mi
- CROUDY, JAMESBrownfields · 1.2 mi
- SLR TRAINING CENTER INCBrownfields · 1.3 mi
- BONSALL UNIFIED SCHOOL DISTRICTBrownfields · 1.8 mi
- 010S003W29C001SNitrate · 1.8 mi
- 010S003W29C002SNitrate · 1.9 mi
- 010S003W20P004SNitrate · 1.9 mi
- 010S003W20P003SNitrate · 1.9 mi
- VVCC HAVENS LP DBA VISTA VALLEY COUNTRY CLUBBrownfields · 1.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Bonsall'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 Bonsall.
Sources Checked
within ~10 miles of Bonsall
Severity Distribution
within ~10 miles of Bonsall
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Bonsall, Brownfields runs higher than the national average — 1,645 sites within ~10 miles of Bonsall. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in Bonsall
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 Bonsall average
Your land is one point inside Bonsall
Everything above resolves to Bonsall as a whole — one PHZM band, read across 9K acres, with hard-freeze dates borrowed from San Diego 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 Bonsall Average
Bonsall Average
- ●USDA Zones 10a, averaged across Bonsall
- ●One soil character for all of Bonsall
- ●Frost dates read at Bonsall's scale: Feb 3 to Dec 11
YOUR Parcel
- ✓Your exact zone, not Bonsall's 10a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Bonsall
Pull a site-specific report for your exact address in Bonsall, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Bonsall averages can't show:
We read public map data around Bonsall — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Bonsall average
How we know this about Bonsall
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 San Diego 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 Bonsall
When does frost risk typically end in Bonsall?
The last hard freeze (28°F) in Bonsall typically lands around Feb 3, 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 24.
When is the first frost in Bonsall?
The first hard freeze (28°F) in Bonsall typically arrives around Dec 11, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 27, so the watching starts about Nov 11 — about 311 days after the spring freeze cleared.
How long is the growing season in Bonsall?
Measured between 28°F hard freezes, Bonsall sees about 311 frost-free days — roughly Feb 3 through Dec 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 24 to Nov 27, about 276 days.
Is the soil safe to grow vegetables in Bonsall?
The federal record around Bonsall is a meaningful one — 2,201 documented sites, mostly Brownfields entries (1,645), the nearest Brownfields record about 0.4 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 Bonsall?
From about Nov 11 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 11 (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 11. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Bonsall's scale — its 10a band and its 311-day season. Your yard writes its own version of Bonsall'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 Bonsall’s own scale
6 of the readings below were taken at Bonsall's own scale — the 8,719 acres it covers and 2,201 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Bonsall's own USDA hardiness band, zones 10aUSDA PHZM 2023
- 2,201 documented contamination sites on the federal record near Bonsall, the closest Brownfields record about 0.4 miles out from the town centreFederal environmental registers
- Bonsall's boundary and the 8,719 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 10a and a ~311-day seasonGrowable Ground crop-matching engine
- The ecoregion at Bonsall's own centroid, the Southern California/Northern Baja CoastUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Bonsalllydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- The 28°F hard-freeze dates — Bonsall has no normal of its own, so its county's is the closest measured readfrom San Diego County
- Soil character — no town-scale survey exists, so Bonsall's 8,719 acres read through its county's SSURGO summaryfrom San Diego County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom San Diego 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 San Diego County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Bonsall's 8,719 acreswhy one lot differs from the next →
- Which side of Bonsall you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 8,719 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.4 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 Bonsall-wide figureread your own land →
More in California
Wider growing context
What grows across CaliforniaBonsall sits outside our named growing regions, so California as a whole is its closest context here.
Nearby growing guides