Whitley Gardens, California, sits in USDA hardiness zone 9a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Well-matched crops include tomato, artichoke, fig, and california poppy, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Whitley Gardens, 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 Whitley Gardens 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 Whitley Gardens — soil, climate, flood, and parcel records. How we handle your address.
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Whitley Gardens — the short answer
Whitley Gardens, California: USDA zone 9a, about 228 days between hard freezes, across 840 acres of town.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 1
- San Luis Obispo County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 15
- San Luis Obispo County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~228
- San Luis Obispo County normal — NOAA 1991–2020, nearest to this town
- Town area
- 840 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 Luis Obispo County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9a is Whitley Gardens's average, not your lot's — a low corner or a tree line moves it. Against Whitley Gardens's 228-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Whitley Gardens
Each reading below is measured for Whitley Gardens itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsWhitley Gardens runs about 228 days between hard freezes (read from San Luis Obispo County, the closest normal to Whitley Gardens) — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredWhitley Gardens 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 Whitley Gardens is in
Whitley Gardens sits in the Central California Foothills and Coastal Mountains — EPA Level III, inside the wider Mediterranean California. That is read at Whitley Gardens's own centroid rather than borrowed from San Luis Obispo County.
What Grows in Whitley Gardens
Plants matched to Whitley Gardens's USDA zones 9a, 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 Whitley Gardens?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 15 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
What's on the federal record near Whitley Gardens
Closest first, within ~10 miles of Whitley Gardens. Listing isn't leaking, and distance isn't exposure.
- 026S014E19F003MNitrate · 1400 ft
- ESTRELLA RANCHBrownfields · 1.1 mi
- SAN LUIS OBISPO COUNTY INTEGRATED WASTE MANAGEMENT AUTHORITYBrownfields · 1.4 mi
- COASTAL RESEARCH SERVICESBrownfields · 1.8 mi
- JOSEPH CARRASCO VINEYARDSBrownfields · 3.0 mi
- MERIDIAN VINEYARDSBrownfields · 3.5 mi
- MERIDIAN VINEYARDSToxics Release Inventory · 3.5 mi
- CIPCO INC DBA DERBY WINE ESTATES LAURES VINEYARDBrownfields · 5.0 mi
- DIAMOND WEST FARMINGBrownfields · 5.1 mi
- SRAN VINEYARDS LLCBrownfields · 5.1 mi
- 025S013E34D001MNitrate · 5.3 mi
- DRY CREEK VINEYARDBrownfields · 5.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Whitley Gardens'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 Whitley Gardens.
Total Sites
169
within ~10 miles of Whitley Gardens
Risk Level
Moderate
Highest-severity
7 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Whitley Gardens
Severity Distribution
within ~10 miles of Whitley Gardens
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Whitley Gardens, Brownfields runs higher than the national average — 134 sites within ~10 miles of Whitley Gardens. 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 Whitley Gardens
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 Whitley Gardens average
Your land is one point inside Whitley Gardens
Everything above resolves to Whitley Gardens as a whole — one PHZM band, read across 840 acres, with hard-freeze dates borrowed from San Luis Obispo 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 Whitley Gardens Average
Whitley Gardens Average
- ●USDA Zones 9a, averaged across Whitley Gardens
- ●One soil character for all of Whitley Gardens
- ●Frost dates read at Whitley Gardens's scale: Apr 1 to Nov 15
YOUR Parcel
- ✓Your exact zone, not Whitley Gardens's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Whitley Gardens
Pull a site-specific report for your exact address in Whitley Gardens, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Whitley Gardens averages can't show:
We read public map data around Whitley Gardens — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Whitley Gardens average
How we know this about Whitley Gardens
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 Luis Obispo 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 Whitley Gardens
When does frost risk typically end in Whitley Gardens?
The last hard freeze (28°F) in Whitley Gardens typically lands around Apr 1, 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 Apr 22.
When is the first frost in Whitley Gardens?
The first hard freeze (28°F) in Whitley Gardens typically arrives around Nov 15, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 1, so the watching starts about Oct 16 — about 228 days after the spring freeze cleared.
How long is the growing season in Whitley Gardens?
Measured between 28°F hard freezes, Whitley Gardens sees about 228 frost-free days — roughly Apr 1 through Nov 15, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 22 to Nov 1, about 193 days.
Is the soil safe to grow vegetables in Whitley Gardens?
The federal record around Whitley Gardens shows 169 documented sites, mostly Brownfields entries (134), the nearest Nitrate record about 0.3 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do I protect my plants from frost in Whitley Gardens?
From about Oct 16 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 Nov 15 (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 Nov 15. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Whitley Gardens's scale — its 9a band and its 228-day season. Your yard writes its own version of Whitley Gardens'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 Whitley Gardens’s own scale
4 of the readings below were taken at Whitley Gardens's own scale — the 840 acres it covers and 169 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- Whitley Gardens's own USDA hardiness band, zones 9aUSDA PHZM 2023
- 169 documented contamination sites on the federal record near Whitley Gardens, the closest Nitrate record about 0.3 miles out from the town centreFederal environmental registers
- Whitley Gardens's boundary and the 840 acres inside itUS Census TIGER/Line 2025
- The ecoregion at Whitley Gardens's own centroid, the Central California Foothills and Coastal MountainsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Whitley Gardens has no normal of its own, so its county's is the closest measured readfrom San Luis Obispo County
- Soil character — no town-scale survey exists, so Whitley Gardens's 840 acres read through its county's SSURGO summaryfrom San Luis Obispo 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 San Luis Obispo 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 Luis Obispo County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Whitley Gardens's 840 acreswhy one lot differs from the next →
- Which side of Whitley Gardens you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 840 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate 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 Whitley Gardens-wide figureread your own land →