San Lorenzo, California, sits in USDA hardiness zone 10a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
These conditions suit avocado, meyer lemon, tomato, and artichoke — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in San Lorenzo, 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 San Lorenzo 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 San Lorenzo — soil, climate, flood, and parcel records. How we handle your address.
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San Lorenzo — the short answer
San Lorenzo, California: USDA zone 10a, about 334 days between hard freezes, across 2K acres of town.
- USDA zone
- 10a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 12
- Alameda County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 12
- Alameda County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~334
- Alameda County normal — NOAA 1991–2020, nearest to this town
- Town area
- 2K 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 Alameda County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 10a is San Lorenzo's average, not your lot's — a low corner or a tree line moves it. Against San Lorenzo's 334-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in San Lorenzo
Each reading below is measured for San Lorenzo itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsSan Lorenzo runs about 334 days between hard freezes (read from Alameda County, the closest normal to San Lorenzo) — 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
MeasuredSan Lorenzo 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 San Lorenzo is in
San Lorenzo sits in the Central California Foothills and Coastal Mountains — EPA Level III, inside the wider Mediterranean California. That is read at San Lorenzo's own centroid rather than borrowed from Alameda County.
What Grows in San Lorenzo
Plants matched to San Lorenzo'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 San Lorenzo?
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 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jan 12 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 12 — 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.
Documented around San Lorenzo
Spotted lanternfly documented 7 miles from San Lorenzo, first recorded 2023. What to watch for.
What's on the federal record near San Lorenzo
Closest first, within ~10 miles of San Lorenzo. Listing isn't leaking, and distance isn't exposure.
- BARBOUR, TONYBrownfields · 250 ft
- 003S003W13A005MNitrate · 650 ft
- SHEILA FLORYBrownfields · 950 ft
- BRIAN ANDERSONBrownfields · 1100 ft
- SUSAN WAREBrownfields · 1200 ft
- SANDRA ARELLANOBrownfields · 1400 ft
- CHEVRON STATION #5630Brownfields · 1400 ft
- LUBE BOYS 10 MINUTE OIL CHANGEBrownfields · 1500 ft
- TUNEUP MASTERS 327Brownfields · 1500 ft
- GRANT ELEMENTARY SCHOOLBrownfields · 1600 ft
- SAN LORENZO UNIFIED SBrownfields · 1600 ft
- SIMPSON CLEANERSBrownfields · 1700 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from San Lorenzo'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 San Lorenzo.
Total Sites
4,661
within ~10 miles of San Lorenzo
Risk Level
Elevated
Highest-severity
19 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of San Lorenzo
Severity Distribution
within ~10 miles of San Lorenzo
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around San Lorenzo, Brownfields runs higher than the national average — 4,104 sites within ~10 miles of San Lorenzo. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 San Lorenzo
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 San Lorenzo average
Your land is one point inside San Lorenzo
Everything above resolves to San Lorenzo as a whole — one PHZM band, read across 2K acres, with hard-freeze dates borrowed from Alameda 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 San Lorenzo Average
San Lorenzo Average
- ●USDA Zones 10a, averaged across San Lorenzo
- ●One soil character for all of San Lorenzo
- ●Frost dates read at San Lorenzo's scale: Jan 12 to Dec 12
YOUR Parcel
- ✓Your exact zone, not San Lorenzo's 10a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in San Lorenzo
Pull a site-specific report for your exact address in San Lorenzo, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that San Lorenzo averages can't show:
We read public map data around San Lorenzo — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the San Lorenzo average
How we know this about San Lorenzo
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 Alameda 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 San Lorenzo
When does frost risk typically end in San Lorenzo?
The last hard freeze (28°F) in San Lorenzo typically lands around Jan 12, 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 2.
When is the first frost in San Lorenzo?
The first hard freeze (28°F) in San Lorenzo typically arrives around Dec 12, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 28, so the watching starts about Nov 12 — about 334 days after the spring freeze cleared.
How long is the growing season in San Lorenzo?
Measured between 28°F hard freezes, San Lorenzo sees about 334 frost-free days — roughly Jan 12 through Dec 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 2 to Nov 28, about 299 days.
Is the soil safe to grow vegetables in San Lorenzo?
The federal record around San Lorenzo is a meaningful one — 4,661 documented sites, mostly Brownfields entries (4,104), the nearest Brownfields record under a tenth of a mile 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 San Lorenzo?
From about Nov 12 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 12 (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 12. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at San Lorenzo's scale — its 10a band and its 334-day season. Your yard writes its own version of San Lorenzo'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 San Lorenzo’s own scale
5 of the readings below were taken at San Lorenzo's own scale — the 1,949 acres it covers and 4,661 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- San Lorenzo's own USDA hardiness band, zones 10aUSDA PHZM 2023
- 4,661 documented contamination sites on the federal record near San Lorenzo, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- San Lorenzo's boundary and the 1,949 acres inside itUS Census TIGER/Line 2025
- The ecoregion at San Lorenzo's own centroid, the Central California Foothills and Coastal MountainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of San Lorenzolydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- The 28°F hard-freeze dates — San Lorenzo has no normal of its own, so its county's is the closest measured readfrom Alameda County
- Soil character — no town-scale survey exists, so San Lorenzo's 1,949 acres read through its county's SSURGO summaryfrom Alameda 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 Alameda 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 Alameda County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among San Lorenzo's 1,949 acreswhy one lot differs from the next →
- Which side of San Lorenzo you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,949 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record under a tenth of a mile 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 San Lorenzo-wide figureread your own land →