El Sobrante, California, sits in USDA hardiness zone 10a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
On paper, avocado, meyer lemon, tomato, and artichoke all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in El Sobrante, 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 El Sobrante 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 El Sobrante — soil, climate, flood, and parcel records. How we handle your address.
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El Sobrante — the short answer
El Sobrante, California: USDA zone 10a, about 303 days between hard freezes, across 5K acres of town.
- USDA zone
- 10a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 13
- Riverside County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 13
- Riverside County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~303
- Riverside County normal — NOAA 1991–2020, nearest to this town
- Town area
- 5K 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 Riverside County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 10a is El Sobrante's average, not your lot's — a low corner or a tree line moves it. Against El Sobrante's 303-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in El Sobrante
Each reading below is measured for El Sobrante itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsEl Sobrante runs about 303 days between hard freezes (read from Riverside County, the closest normal to El Sobrante) — 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
MeasuredEl Sobrante 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 El Sobrante is in
El Sobrante sits in the Southern California/Northern Baja Coast — EPA Level III, inside the wider Mediterranean California. That is read at El Sobrante's own centroid, and it is not what its county reads: Riverside County is mostly Sonoran Basin and Range. The wider page above you is answering a different question about different ground.
What Grows in El Sobrante
Plants matched to El Sobrante's USDA zones 10a, 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 El Sobrante?
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 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 13 — 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 El Sobrante
Closest first, within ~10 miles of El Sobrante. Listing isn't leaking, and distance isn't exposure.
- GEORGE KANALYBrownfields · 0.9 mi
- MICHEAL HUGHESBrownfields · 1.0 mi
- AY NURSERY INCBrownfields · 1.4 mi
- WILD BEAR RANCHBrownfields · 1.4 mi
- MWD - Lake Mathews Reservoir FacilityUnderground Storage Tanks · 1.4 mi
- LAKE MATHEWS RESERVOIRBrownfields · 1.4 mi
- PIPPIN AND SON TRUCKINGBrownfields · 1.6 mi
- CALIFORNIA OIL REFINERY INCBrownfields · 1.7 mi
- WEST COAST DENTAL OF RIVERSIDEBrownfields · 1.7 mi
- LA SIERRA VERDE CLEANERSBrownfields · 1.7 mi
- Chevron Station# 200734/1485Underground Storage Tanks · 1.7 mi
- CHEVRON STATION NO 200734Brownfields · 1.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from El Sobrante'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 El Sobrante.
Sources Checked
within ~10 miles of El Sobrante
Severity Distribution
within ~10 miles of El Sobrante
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around El Sobrante, Brownfields runs higher than the national average — 2,874 sites within ~10 miles of El Sobrante. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
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 El Sobrante
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 El Sobrante average
Your land is one point inside El Sobrante
Everything above resolves to El Sobrante as a whole — one PHZM band, read across 5K acres, with hard-freeze dates borrowed from Riverside 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 El Sobrante Average
El Sobrante Average
- ●USDA Zones 10a, averaged across El Sobrante
- ●One soil character for all of El Sobrante
- ●Frost dates read at El Sobrante's scale: Feb 13 to Dec 13
YOUR Parcel
- ✓Your exact zone, not El Sobrante's 10a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in El Sobrante
Pull a site-specific report for your exact address in El Sobrante, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that El Sobrante averages can't show:
We read public map data around El Sobrante — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the El Sobrante average
How we know this about El Sobrante
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 Riverside 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 El Sobrante
When does frost risk typically end in El Sobrante?
The last hard freeze (28°F) in El Sobrante typically lands around Feb 13, 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 Mar 6.
When is the first frost in El Sobrante?
The first hard freeze (28°F) in El Sobrante typically arrives around Dec 13, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 29, so the watching starts about Nov 13 — about 303 days after the spring freeze cleared.
How long is the growing season in El Sobrante?
Measured between 28°F hard freezes, El Sobrante sees about 303 frost-free days — roughly Feb 13 through Dec 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 6 to Nov 29, about 268 days.
Is the soil safe to grow vegetables in El Sobrante?
The federal record around El Sobrante runs heavier than most — 3,328 documented sites, mostly Brownfields entries (2,874), the nearest Brownfields record about 0.9 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in El Sobrante?
From about Nov 13 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 13 (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 13. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at El Sobrante's scale — its 10a band and its 303-day season. Your yard writes its own version of El Sobrante'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 El Sobrante’s own scale
4 of the readings below were taken at El Sobrante's own scale — the 4,629 acres it covers and 3,328 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- El Sobrante's own USDA hardiness band, zones 10aUSDA PHZM 2023
- 3,328 documented contamination sites on the federal record near El Sobrante, the closest Brownfields record about 0.9 miles out from the town centreFederal environmental registers
- El Sobrante's boundary and the 4,629 acres inside itUS Census TIGER/Line 2025
- El Sobrante sits in the Southern California/Northern Baja Coast — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — El Sobrante has no normal of its own, so its county's is the closest measured readfrom Riverside County
- Soil character — no town-scale survey exists, so El Sobrante's 4,629 acres read through its county's SSURGO summaryfrom Riverside 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 Riverside 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 Riverside County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among El Sobrante's 4,629 acreswhy one lot differs from the next →
- Which side of El Sobrante you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 4,629 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.9 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 El Sobrante-wide figureread your own land →
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