Leona Valley, California, sits in USDA hardiness zone 9a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Reliable performers under these conditions include artichoke, fig, california poppy, and cabbage; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Leona 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 Leona 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 Leona Valley — soil, climate, flood, and parcel records. How we handle your address.
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Leona Valley — the short answer
Leona Valley, California: USDA zone 9a, about 309 days between hard freezes, across 12K acres of town.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Dec 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~309
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 12K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 9a is Leona Valley's average, not your lot's — a low corner or a tree line moves it. Against Leona Valley's 309-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Leona Valley
Each reading below is measured for Leona Valley itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredLeona Valley runs about 309 days between hard freezes — 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
MeasuredLeona Valley sits in USDA hardiness zone 9a.
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 Leona Valley is in
Leona Valley sits in the Southern California Mountains — EPA Level III, inside the wider Mediterranean California. That is read at Leona Valley's own centroid, and it is not what its county reads: Los Angeles County is mostly Southern California/Northern Baja Coast. The wider page above you is answering a different question about different ground.
What Grows in Leona Valley
Every plant below cleared Leona Valley's own zone 9a and its 309-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in Leona Valley?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Jan 10; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 7 (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. 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 Leona Valley
Closest first, within ~10 miles of Leona Valley. Listing isn't leaking, and distance isn't exposure.
- COLLINS, ROBERTBrownfields · 0.7 mi
- ERIC ALPERNBrownfields · 0.8 mi
- PACIFIC BELLBrownfields · 0.8 mi
- RANCHERS MARKETUnderground Storage Tanks · 1.0 mi
- LOS ANGELES COUNTY FIRE DEPARTMENTBrownfields · 1.1 mi
- 006N013W04H001SNitrate · 3.4 mi
- ANTELOPE VALLEY E KERN WATER AGENCYBrownfields · 3.6 mi
- STEVEN BANKS DBA SWB TRUCKING COMPANYBrownfields · 3.7 mi
- MAYFLOWER GARDENBrownfields · 4.2 mi
- RETIREMENT HOUSING FOUNDATIONBrownfields · 4.2 mi
- PALM RANCH IRRIGATION DIST.PFAS · 4.4 mi
- QUARTZ HILL WATER DIST.PFAS · 4.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Leona 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 Leona Valley.
Total Sites
633
within ~10 miles of Leona Valley
Risk Level
Elevated
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Leona Valley
Severity Distribution
within ~10 miles of Leona Valley
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Leona Valley, two things run higher than the national average within ~10 miles of Leona Valley — Brownfields (408 sites) and Nitrate (166 sites). 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.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Leona 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 Leona Valley average
Your land is one point inside Leona Valley
Everything above resolves to Leona Valley as a whole — one PHZM band and one 28°F frost record, read across 12K 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 Leona Valley Average
Leona Valley Average
- ●USDA Zones 9a, averaged across Leona Valley
- ●One soil character for all of Leona Valley
- ●Frost dates read at Leona Valley's scale: Feb 7 to Dec 13
YOUR Parcel
- ✓Your exact zone, not Leona Valley's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Leona Valley
Pull a site-specific report for your exact address in Leona Valley, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Leona Valley averages can't show:
We read public map data around Leona Valley — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Leona Valley average
How we know this about Leona 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 Leona Valley’s own record; 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 Leona Valley
When does frost risk typically end in Leona Valley?
The last hard freeze (28°F) in Leona Valley typically lands around Feb 7, 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 28.
When is the first frost in Leona Valley?
The first hard freeze (28°F) in Leona 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 309 days after the spring freeze cleared.
How long is the growing season in Leona Valley?
Measured between 28°F hard freezes, Leona Valley sees about 309 frost-free days — roughly Feb 7 through Dec 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 28 to Nov 29, about 274 days.
Is the soil safe to grow vegetables in Leona Valley?
The federal record around Leona Valley is a meaningful one — 633 documented sites, mostly Brownfields entries (408), the nearest Brownfields record about 0.7 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 Leona 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 Leona Valley's scale — its 9a band and its 309-day season. Your yard writes its own version of Leona 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 Leona Valley’s own scale
6 of the readings below were taken at Leona Valley's own scale — its own ~309-day season between 28°F freezes, the 11,900 acres it covers and 633 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Leona Valley's own USDA hardiness band, zones 9aUSDA PHZM 2023
- Leona Valley's own 28°F hard-freeze dates, about Feb 7 and Dec 13 and the ~309-day span between themNOAA 1991–2020 Climate Normals
- 633 documented contamination sites on the federal record near Leona Valley, the closest Brownfields record about 0.7 miles out from the town centreFederal environmental registers
- Leona Valley's boundary and the 11,900 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~309-day seasonGrowable Ground crop-matching engine
- Leona Valley sits in the Southern California Mountains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Leona Valley's 11,900 acres read through its county's SSURGO summaryfrom Los Angeles County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Los Angeles 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 Los Angeles County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Leona Valley's 11,900 acreswhy one lot differs from the next →
- Which side of Leona 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 11,900 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.7 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 Leona Valley-wide figureread your own land →