San Joaquin, California, sits in USDA hardiness zone 9a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
These conditions suit tomato, artichoke, fig, and california poppy — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in San Joaquin, 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 Joaquin 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 Joaquin — soil, climate, flood, and parcel records. How we handle your address.
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San Joaquin — the short answer
San Joaquin, California: USDA zone 9a, about 329 days between hard freezes, across 746 acres of city.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 16
- Fresno County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 11
- Fresno County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~329
- Fresno County normal — NOAA 1991–2020, nearest to this town
- City area
- 746 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 Fresno County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9a is San Joaquin's average, not your lot's — a low corner or a tree line moves it. Against San Joaquin's 329-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in San Joaquin
Each reading below is measured for San Joaquin itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsSan Joaquin runs about 329 days between hard freezes (read from Fresno County, the closest normal to San Joaquin) — 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 Joaquin 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 San Joaquin is in
San Joaquin sits in the Central California Valley — EPA Level III, inside the wider Mediterranean California. That is read at San Joaquin's own centroid rather than borrowed from Fresno County.
What Grows in San Joaquin
Plants matched to San Joaquin'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 San Joaquin?
Rarely: the season closes in stages, not all at once, and each stage has its crops. 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 16 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 11 — long-season crops need about 90 days of runway, quick greens only 30. Here the calendar nearly circles: cool-season crops take the winter shift, and the next window is always close.
What's on the federal record near San Joaquin
Closest first, within ~10 miles of San Joaquin. Listing isn't leaking, and distance isn't exposure.
- 015S016E23R001MNitrate · 400 ft
- JAMES IRRIGATION DISTRICTBrownfields · 450 ft
- 015S016E23J001MNitrate · 500 ft
- CIRCLE K STORES INCBrownfields · 750 ft
- CIRCLE K STORES INC 2703608Brownfields · 750 ft
- D's Mini MartUnderground Storage Tanks · 750 ft
- WEST HILL OIL, INC., SAN JOAQUINBrownfields · 850 ft
- Circle K Store #2703608Underground Storage Tanks · 850 ft
- OPC FARMS INCBrownfields · 1400 ft
- FREEDOM AUTOMOTIVEBrownfields · 1800 ft
- WILBUR-ELLIS RNA-SAN JOAQUINToxics Release Inventory · 2200 ft
- WILBUR-ELLIS RNA-SAN JOAQUINBrownfields · 2200 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from San Joaquin'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 Joaquin.
Total Sites
301
within ~10 miles of San Joaquin
Risk Level
Elevated
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of San Joaquin
Severity Distribution
within ~10 miles of San Joaquin
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around San Joaquin, Nitrate runs higher than the national average — 216 sites within ~10 miles of San Joaquin. 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.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in San Joaquin
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 Joaquin average
Your land is one point inside San Joaquin
Everything above resolves to San Joaquin as a whole — one PHZM band, read across 746 acres, with hard-freeze dates borrowed from Fresno County’s record because no 30-year normal resolves at this city’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 city 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 Joaquin Average
San Joaquin Average
- ●USDA Zones 9a, averaged across San Joaquin
- ●One soil character for all of San Joaquin
- ●Frost dates read at San Joaquin's scale: Jan 16 to Dec 11
YOUR Parcel
- ✓Your exact zone, not San Joaquin's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in San Joaquin
Pull a site-specific report for your exact address in San Joaquin, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that San Joaquin averages can't show:
We read public map data around San Joaquin — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the San Joaquin average
How we know this about San Joaquin
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Fresno 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 city grain anywhere on this page — there is no city-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 Joaquin
When does frost risk typically end in San Joaquin?
The last hard freeze (28°F) in San Joaquin typically lands around Jan 16, 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 6.
When is the first frost in San Joaquin?
The first hard freeze (28°F) in San Joaquin typically arrives around Dec 11, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 27, so the watching starts about Nov 11 — about 329 days after the spring freeze cleared.
How long is the growing season in San Joaquin?
Measured between 28°F hard freezes, San Joaquin sees about 329 frost-free days — roughly Jan 16 through Dec 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 6 to Nov 27, about 294 days.
Is the soil safe to grow vegetables in San Joaquin?
The federal record around San Joaquin is a meaningful one — 301 documented sites, mostly Nitrate entries (216), the nearest Nitrate 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 Joaquin?
From about Nov 11 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 11 (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 11. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at San Joaquin's scale — its 9a band and its 329-day season. Your yard writes its own version of San Joaquin'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 Joaquin’s own scale
4 of the readings below were taken at San Joaquin's own scale — the 746 acres it covers and 301 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- San Joaquin's own USDA hardiness band, zones 9aUSDA PHZM 2023
- 301 documented contamination sites on the federal record near San Joaquin, the closest Nitrate record under a tenth of a mile out from the town centreFederal environmental registers
- San Joaquin's boundary and the 746 acres inside itUS Census TIGER/Line 2025
- The ecoregion at San Joaquin's own centroid, the Central California ValleyUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — San Joaquin has no normal of its own, so its county's is the closest measured readfrom Fresno County
- Soil character — no town-scale survey exists, so San Joaquin's 746 acres read through its county's SSURGO summaryfrom Fresno 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 Fresno 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 Fresno County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among San Joaquin's 746 acreswhy one lot differs from the next →
- Which side of San Joaquin you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 746 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate 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 Joaquin-wide figureread your own land →