French Valley, 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.
Growers here do well with okra, meyer lemon, california poppy, and artichoke — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in French Valley, 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 French Valley 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 French Valley — soil, climate, flood, and parcel records. How we handle your address.
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French Valley — the short answer
French Valley, California: USDA zone 9b, about 303 days between hard freezes, across 7K acres of town.
- USDA zone
- 9b
- 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
- 7K 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 9b is French Valley's average, not your lot's — a low corner or a tree line moves it. Against French Valley's 303-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in French Valley
Each reading below is measured for French Valley itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsFrench Valley runs about 303 days between hard freezes (read from Riverside County, the closest normal to French Valley) — 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
MeasuredFrench Valley 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 French Valley is in
French Valley sits in the Southern California/Northern Baja Coast — EPA Level III, inside the wider Mediterranean California. That is read at French Valley'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 French Valley
Every plant below cleared French Valley's own zone 9b and its 303-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in French Valley?
Almost never — the real question is what to plant next. 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. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.
What's on the federal record near French Valley
Closest first, within ~10 miles of French Valley. Listing isn't leaking, and distance isn't exposure.
- 007S002W05C001SNitrate · 1300 ft
- 007S002W04D001SNitrate · 0.5 mi
- JUDY WILLIAMSBrownfields · 0.6 mi
- 006S002W32H001SNitrate · 0.7 mi
- O'REILLY AUTO PARTS #6046Brownfields · 0.7 mi
- 006S002W33E001SNitrate · 0.7 mi
- 007S002W05L001SNitrate · 0.8 mi
- 006S002W32A001SNitrate · 0.8 mi
- 006S002W29R001SNitrate · 1.0 mi
- CLASSIC COLLISION - FRENCH VALLEYBrownfields · 1.0 mi
- JIM ANDERSONBrownfields · 1.0 mi
- STATER BROS MARKETS # 177Brownfields · 1.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from French Valley'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 French Valley.
Total Sites
1,851
within ~10 miles of French Valley
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of French Valley
Severity Distribution
within ~10 miles of French Valley
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around French Valley, two things run higher than the national average within ~10 miles of French Valley — Nitrate (622 sites) and Brownfields (1,109 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in French Valley
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 French Valley average
Your land is one point inside French Valley
Everything above resolves to French Valley as a whole — one PHZM band, read across 7K 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 French Valley Average
French Valley Average
- ●USDA Zones 9b, averaged across French Valley
- ●One soil character for all of French Valley
- ●Frost dates read at French Valley's scale: Feb 13 to Dec 13
YOUR Parcel
- ✓Your exact zone, not French Valley's 9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in French Valley
Pull a site-specific report for your exact address in French Valley, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that French Valley averages can't show:
We read public map data around French Valley — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the French Valley average
How we know this about French Valley
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 French Valley
When does frost risk typically end in French Valley?
The last hard freeze (28°F) in French Valley 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 French Valley?
The first hard freeze (28°F) in French Valley 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 French Valley?
Measured between 28°F hard freezes, French Valley 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 French Valley?
The federal record around French Valley is a meaningful one — 1,851 documented sites, mostly Brownfields entries (1,109), the nearest Nitrate 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 French Valley?
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 French Valley's scale — its 9b band and its 303-day season. Your yard writes its own version of French Valley'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 French Valley’s own scale
5 of the readings below were taken at French Valley's own scale — the 6,957 acres it covers and 1,851 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- French Valley's own USDA hardiness band, zones 9bUSDA PHZM 2023
- 1,851 documented contamination sites on the federal record near French Valley, the closest Nitrate record about 0.2 miles out from the town centreFederal environmental registers
- French Valley's boundary and the 6,957 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~303-day seasonGrowable Ground crop-matching engine
- French Valley 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 — French Valley 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 French Valley's 6,957 acres read through its county's SSURGO summaryfrom Riverside County
- 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 French Valley's 6,957 acreswhy one lot differs from the next →
- Which side of French Valley you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 6,957 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate 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 French Valley-wide figureread your own land →
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