El Rio, California, sits in USDA hardiness zone 10a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
On paper, artichoke, meyer lemon, california poppy, and cabbage all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in El Rio, 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 Rio 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 Rio — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
El Rio — the short answer
El Rio, California: USDA zone 10a, no 28°F killing freeze on record — the season is year-round, across 1K acres of town.
- USDA zone
- 10a
- USDA PHZM 2023
- Killing freeze
- None on record
- NOAA RCC ACIS 1991–2020, this town’s own record
- Town area
- 1K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. The year-round finding is measured — a 30-year record with no 28°F killing freeze in it — never inferred from missing dates.
Hardiness Zone Range
Zone 10a is El Rio's average, not your lot's — a low corner or a tree line moves it. Against El Rio's no killing freeze on record, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in El Rio
Each reading below is measured for El Rio itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Winter hardiness
MeasuredEl Rio 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 Rio is in
El Rio sits in the Southern California/Northern Baja Coast — EPA Level III, inside the wider Mediterranean California. That is read at El Rio's own centroid, and it is not what its county reads: Ventura County is mostly Southern California Mountains. The wider page above you is answering a different question about different ground.
What Grows in El Rio
Every plant below cleared El Rio's own zone 10a. Each card opens that plant's California profile. How we score.
What's on the federal record near El Rio
Closest first, within ~10 miles of El Rio. Listing isn't leaking, and distance isn't exposure.
- OXNARD WATER DEPTPFAS · 1400 ft
- SOUTHERN COUNTIES OIL CO., LP D.B.A. SC FUELSToxics Release Inventory · 1700 ft
- BARON INDUSTRIESBrownfields · 1700 ft
- 002N022W23B007SNitrate · 1800 ft
- 002N022W23B006SNitrate · 1800 ft
- 002N022W23B005SNitrate · 1800 ft
- 002N022W23B003SNitrate · 1800 ft
- 002N022W23B004SNitrate · 1800 ft
- HANSON AGGREGATES WEST INCBrownfields · 1900 ft
- COUNTY OF VENTURA - DEPT OF ENV & ENERGY RSRCSBrownfields · 1900 ft
- SOUTHERN COUNTIES OIL COMPANY, A CALIFORNIA LP DBA SC FUELSBrownfields · 1900 ft
- Southern Counties Oil, DBA SC FuelsUnderground Storage Tanks · 1900 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from El Rio'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 Rio.
Sources Checked
within ~10 miles of El Rio
Severity Distribution
within ~10 miles of El Rio
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around El Rio, Brownfields runs higher than the national average — 2,639 sites within ~10 miles of El Rio. 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.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in El Rio
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 Rio average
Your land is one point inside El Rio
Everything above resolves to El Rio as a whole — one PHZM band and one 28°F frost record, read across 1K 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 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 Rio Average
El Rio Average
- ●USDA Zones 10a, averaged across El Rio
- ●One soil character for all of El Rio
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not El Rio's 10a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in El Rio
Pull a site-specific report for your exact address in El Rio, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that El Rio averages can't show:
We read public map data around El Rio — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the El Rio average
How we know this about El Rio
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, with the labelled statewide window where none resolves; 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 Rio
Is it too late to plant in El Rio?
No — El Rio has no 28°F killing freeze in the 30-year station record, so the growing season is year-round and there is no last-frost date to wait for. Planting is paced by rainfall, heat and daylength instead of by frost: start heat-lovers any month, and time cool-season crops (lettuce, brassicas, peas) for the cooler, wetter half of the year or for higher ground. Succession sowing every few weeks works all year, so the limit is what you can keep watered and harvested, not the calendar.
When does frost risk typically end in El Rio?
It doesn't — El Rio records no 28°F killing freeze at all across the 1991–2020 station record, so there is no spring frost date to plant after. Cold still matters with elevation: the higher you garden, the cooler the nights, and a few tropical crops sulk below about 60°F even where they never freeze.
How long is the growing season in El Rio?
Year-round — the 1991–2020 station record for El Rio contains no 28°F killing freeze, so there is no season to measure between freezes. What paces planting instead is heat, rainfall and daylength: the hottest, wettest stretch is the hard part for cool-season crops, not winter. Elevation is the one real exception — the higher you garden, the colder the nights get.
Is the soil safe to grow vegetables in El Rio?
The federal record around El Rio is a meaningful one — 3,191 documented sites, mostly Brownfields entries (2,639), the nearest PFAS record about 0.3 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.
Everything above is measured at El Rio's scale — its 10a band and its no killing freeze on record. Your yard writes its own version of El Rio'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 Rio’s own scale
6 of the readings below were taken at El Rio's own scale — the 1,290 acres it covers and 3,191 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- El Rio's own USDA hardiness band, zones 10aUSDA PHZM 2023
- No 28°F killing freeze in the 30-year station record covering El Rio — a year-round growing seasonNOAA Regional Climate Centers ACIS, 1991-2020
- 3,191 documented contamination sites on the federal record near El Rio, the closest PFAS record about 0.3 miles out from the town centreFederal environmental registers
- El Rio's boundary and the 1,290 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear El Rio's hardiness zoneGrowable Ground crop-matching engine
- El Rio sits in the Southern California/Northern Baja Coast — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so El Rio's 1,290 acres read through its county's SSURGO summaryfrom Ventura County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Ventura 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 Ventura County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among El Rio's 1,290 acreswhy one lot differs from the next →
- Which side of El Rio you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,290 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest PFAS record about 0.3 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 Rio-wide figureread your own land →