San Martin, California, sits in USDA hardiness zone 9b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
On paper, okra, meyer lemon, california poppy, and artichoke all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in San Martin, 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 Martin 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 Martin — soil, climate, flood, and parcel records. How we handle your address.
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San Martin — the short answer
San Martin, California: USDA zone 9b, about 331 days between hard freezes, across 7K acres of town.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 17
- Santa Clara County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 14
- Santa Clara County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~331
- Santa Clara 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 Santa Clara County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9b is San Martin's average, not your lot's — a low corner or a tree line moves it. Against San Martin's 331-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in San Martin
Each reading below is measured for San Martin itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsSan Martin runs about 331 days between hard freezes (read from Santa Clara County, the closest normal to San Martin) — 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 Martin 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 San Martin is in
San Martin sits in the Central California Foothills and Coastal Mountains — EPA Level III, inside the wider Mediterranean California. That is read at San Martin's own centroid rather than borrowed from Santa Clara County.
What Grows in San Martin
Every plant below cleared San Martin's own zone 9b and its 331-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in San Martin?
Almost never — the real question is what to plant next. 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 17 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 14 — 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 San Martin
Closest first, within ~10 miles of San Martin. Listing isn't leaking, and distance isn't exposure.
- TRINCHERO CONSTRUCTIONBrownfields · 750 ft
- SANTA CLARA ROADS & AIRPORTS - SOUTH COUNTY AIRPORTBrownfields · 1300 ft
- MAGNUM AVIATIONBrownfields · 1300 ft
- ROSA MANLEYBrownfields · 1400 ft
- GAVILAN COMMUNITY COLLEGE DISTRICTBrownfields · 1400 ft
- PETERSON TRACTOR COBrownfields · 1900 ft
- 010S003E12M001MNitrate · 0.5 mi
- COPART INC DBA COPARTBrownfields · 0.5 mi
- KW VONG FARMBrownfields · 0.5 mi
- PRIVATE SPRING WATERBrownfields · 0.5 mi
- County of Santa Clara FAF - South Yard Fleet FacilityUnderground Storage Tanks · 0.6 mi
- SAN MARTIN WINERYBrownfields · 0.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from San Martin'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 Martin.
Total Sites
821
within ~10 miles of San Martin
Risk Level
Elevated
Highest-severity
20 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of San Martin
Severity Distribution
within ~10 miles of San Martin
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around San Martin, Brownfields runs higher than the national average — 678 sites within ~10 miles of San Martin. 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 San Martin
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 Martin average
Your land is one point inside San Martin
Everything above resolves to San Martin as a whole — one PHZM band, read across 7K acres, with hard-freeze dates borrowed from Santa Clara 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 Martin Average
San Martin Average
- ●USDA Zones 9b, averaged across San Martin
- ●One soil character for all of San Martin
- ●Frost dates read at San Martin's scale: Jan 17 to Dec 14
YOUR Parcel
- ✓Your exact zone, not San Martin's 9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in San Martin
Pull a site-specific report for your exact address in San Martin, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that San Martin averages can't show:
We read public map data around San Martin — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the San Martin average
How we know this about San Martin
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 Santa Clara 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 Martin
When does frost risk typically end in San Martin?
The last hard freeze (28°F) in San Martin typically lands around Jan 17, 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 7.
When is the first frost in San Martin?
The first hard freeze (28°F) in San Martin typically arrives around Dec 14, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 30, so the watching starts about Nov 14 — about 331 days after the spring freeze cleared.
How long is the growing season in San Martin?
Measured between 28°F hard freezes, San Martin sees about 331 frost-free days — roughly Jan 17 through Dec 14, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 7 to Nov 30, about 296 days.
Is the soil safe to grow vegetables in San Martin?
The federal record around San Martin is a meaningful one — 821 documented sites, mostly Brownfields entries (678), the nearest Brownfields record about 0.1 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 San Martin?
From about Nov 14 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 14 (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 14. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at San Martin's scale — its 9b band and its 331-day season. Your yard writes its own version of San Martin'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 Martin’s own scale
5 of the readings below were taken at San Martin's own scale — the 7,424 acres it covers and 821 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- San Martin's own USDA hardiness band, zones 9bUSDA PHZM 2023
- 821 documented contamination sites on the federal record near San Martin, the closest Brownfields record about 0.1 miles out from the town centreFederal environmental registers
- San Martin's boundary and the 7,424 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~331-day seasonGrowable Ground crop-matching engine
- The ecoregion at San Martin'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 — San Martin has no normal of its own, so its county's is the closest measured readfrom Santa Clara County
- Soil character — no town-scale survey exists, so San Martin's 7,424 acres read through its county's SSURGO summaryfrom Santa Clara County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Santa Clara 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 Santa Clara County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among San Martin's 7,424 acreswhy one lot differs from the next →
- Which side of San Martin you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 7,424 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.1 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 San Martin-wide figureread your own land →
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