The San Joaquin Valley spans USDA hardiness zones 9a-9b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
The hot southern half of California's Central Valley — deep soils and intense sun behind almonds, stone fruit, grapes, and row crops at vast scale. Growers here do well with tomato, artichoke, fig, and california poppy — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
The San Joaquin Valley spans California.
Your yard isn't all of the San Joaquin Valley.
The San Joaquin Valley spans USDA zones 9a-9b, but your parcel sits in exactly one — and slope, tree cover, and low spots nudge it further. 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 Valley — soil, climate, flood, and parcel records. How we handle your address.
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The San Joaquin Valley — the short answer
The San Joaquin Valley: USDA zones 9a-9b, 296–329 frost-free days depending where in it you stand, in California.
- USDA zones
- 9a-9b
- USDA PHZM 2023, aggregated over the footprint
- Shortest season here
- 296 days
- NOAA Regional Climate Centers ACIS, 1991-2020 — Tulare County
- Counties
- 8
- US Census TIGER/Line 2025
- Region type
- County cluster
- Growable Ground growing-region registry
Region boundary: Growable Ground growing-region registry — curated county clusters, EPA Level III ecoregions, and town clusters drawn finer than any county. The season figure is this region's own record, measured across its 8 member counties, not a state or national average.
Hardiness Zone Range
The San Joaquin Valley is not one growing season
One answer for the San Joaquin Valley averages 8 counties whose growing seasons are 33 days apart — from 296 frost-free days in Tulare County to 329 in Fresno County. That is the same region, measured the same way, in the same years. Which end of it your land sits nearer decides what finishes before the first hard freeze.
The middle half of 8 counties runs 315–322 days, with a median of 320 days — a 33-day span end to end.
Measured across 8 member counties, each carrying its own 28°F normal. NOAA Regional Climate Centers ACIS, 1991-2020. A member with no own record is absent from the range rather than counted as zero — nothing here is interpolated to the region. Your own site sits somewhere inside this range; a parcel report resolves where.
Where the line runs inside the San Joaquin Valley
The middle half of the San Joaquin Valley runs 315–322 frost-free days, and 4 of its 8 counties sit outside that — 2 on the short side, 2 on the long. A regional planting date describes the middle well and the ends poorly, which is worth knowing before you follow one.
Under 315 frost-free days
2 counties
- Tulare County · 296 days
- Madera County · 304 days
The end of the region that sets the planting calendar — start seed indoors here and the season stretches to meet the crop.
315–322 frost-free days
4 counties
0 of 4 shown
The middle half of the region, and the part a single regional season describes well.
Over 322 frost-free days
2 counties
- Fresno County · 329 days
- Kings County · 323 days
Long enough for a second succession of a quick crop after the first comes out.
Each county is placed by its OWN 28°F frost-free normal (NOAA Regional Climate Centers ACIS, 1991-2020), the same figure its own guide page publishes. Elevation, slope and cold-air drainage move a site within its county as well — which is the part only your address resolves.
What Grows in the San Joaquin Valley
All 1 of the plants below that publish a season requirement clear even Tulare County’s 296 frost-free days — so on season alone, this grid works at both ends of the region. The 33-day spread still decides how far past this list you can push, and how early you can start.
Plants matched to the San Joaquin Valley's USDA zones 9a-9b, ordered by how much hardiness margin each has across the region — the ones with room to spare at both ends of this band lead. Each links to its full growing profile.
Native Plants of the San Joaquin Valley
Plants the USDA PLANTS Database documents as native and present in this region’s state, kept only where the published hardiness range meets the San Joaquin Valley’s USDA zones 9a-9b — closest range match first. Presence is recorded by state, so a plant can be documented across the state and still be scarce in your corner of the region.
The ground across the San Joaquin Valley
The USDA soil survey maps this ground county by county. These are those records weighted by land area across eight member counties — this region’s own profile, not a state figure.
The ground is predominantly Entisols, at 28% of mapped acres, followed by Alfisols (21%), Mollisols (19%) and Inceptisols (18%). Eight soil orders appear somewhere inside the footprint, which is the honest reason a regional soil answer only goes so far. The most extensive named soils are Cajon, Kimberlina, and Nord.
58% of those acres are well drained, and another 12% somewhat excessively drained, 8% moderately well drained. Topsoil pH runs 5.8–8.3 between the lowest and the highest county on record.
Soil order
Entisols
Drainage
Well drained
Topsoil pH
5.8–8.3
Hydric soils
9%
Soil changes across a driveway, so which of these your own ground sits on is a parcel question rather than a regional one. Kings County holds the most wetland ground here, at 41% — soil types explained.
USDA NRCS SSURGO via Soil Data Access
What this means for growing in the San Joaquin Valley
The soil survey reads this ground county by county, and the readings above are those records summed across the San Joaquin Valley. Here is what they mean for a garden here — and the move an experienced grower makes about each one.
Drainage
From county records58% of the mapped acres across the San Joaquin Valley are well drained — ground that drains quickly. That is area-weighted across all eight of its mapped counties.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
From county recordsTopsoil across the San Joaquin Valley runs pH 5.8–8.3 — near neutral in six of its eight counties.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Safe to Grow Here?
What the federal record shows across the San Joaquin Valley — and how to grow with it.
Across the San Joaquin Valley's 8 counties the federal record holds 32,386 documented sites, mostly Brownfields (20,059), Nitrate (8,882) and Underground Storage Tanks (1,819). The heaviest single county is Kern County, with 8,118.
That is a regional count, not a reading of any one lot — proximity to a documented site is information, not a diagnosis. Open the map outlined to the San Joaquin Valley to see which records sit where you actually grow.
Sources Checked
Summed across the 8 counties in the San Joaquin Valley
A note from Gnorman
What an experienced grower watches for around here
In and around the San Joaquin Valley, two things run higher than the national average across the 8 counties in the San Joaquin Valley — Brownfields (20,059 sites) and Nitrate (8,882 sites). 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.
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).
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
Your land is one point inside the San Joaquin Valley
Everything above resolves to the San Joaquin Valley as a whole — a footprint whose own counties record seasons 33 days apart, and hardiness across zones 9a-9b. Your parcel sits at one point in that range, not in the middle of it. 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 region 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 regional average.
Your Lot vs the San Joaquin Valley Average
San Joaquin Valley Average
- ●USDA Zones 9a-9b, averaged across San Joaquin Valley
- ●One soil character for all of San Joaquin Valley
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not San Joaquin Valley's 9a-9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in the San Joaquin Valley
Pull a site-specific report for your exact address in the San Joaquin Valley — soil, sun, drainage, frost risk, contamination, and scored plant recommendations.
Three things about your lot that San Joaquin Valley averages can't show:
We read public map data around The San Joaquin Valley — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the San Joaquin Valley average
How we know this about the San Joaquin Valley
The boundary: a cluster of neighboring counties. Growing regions have no official boundary, so this footprint is our published one, and every figure on this page was measured over the counties inside it rather than borrowed from the state around it.
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, aggregated across the footprint; the growing season from NOAA Regional Climate Centers ACIS 1991–2020 28°F normals, read at each member’s own record; boundaries from US Census TIGER/Line 2025; the contamination record from the federal sources named in that beat above; the soil from the USDA NRCS SSURGO survey, read at each member county’s own record and weighted to this footprint by land area. Where a member carries no record of its own, it is absent from the figure rather than filled in.
Common questions about the San Joaquin Valley
What hardiness zone is the San Joaquin Valley?
The San Joaquin Valley spans USDA hardiness zones 9a-9b, aggregated from the USDA Agricultural Research Service Plant Hardiness Zone Map 2023 across the region's counties. Zones reflect average annual extreme minimum temperatures from 1991–2020 data.
How long is the growing season in the San Joaquin Valley?
Measured between 28°F hard freezes, the San Joaquin Valley's counties mostly run 315 to 322 frost-free days, median 320 (NOAA Regional Climate Centers ACIS, 1991–2020, over 8 member counties). That 7-day spread is the honest read — no single season describes 8 counties, and each county guide below carries its own.
When does frost risk end in the San Joaquin Valley?
Across the San Joaquin Valley, the middle half of member counties see their last 28°F hard freeze between Jan 20 and Jan 27 (median Jan 23), and their first fall freeze between Dec 6 and Dec 10. Those are hard freezes, not the last light frost: tender transplants wait for about Feb 13, and elevation decides which end of a 7-day spread you garden in.
What grows well in the San Joaquin Valley?
The San Joaquin Valley's conditions suit plants such as Tomato, Artichoke, Fig, California Poppy, Rosemary, Olive. What actually thrives on any one site still turns on its specific soil, sun, and drainage — we score each plant against the real conditions at your address.
How is the San Joaquin Valley defined?
The San Joaquin Valley is defined here as a curated cluster of 8 neighboring counties that share a growing character. Growing regions have no official boundary, so this footprint is our published one — every county in it is named on this page.
Which states does the San Joaquin Valley cover?
The San Joaquin Valley spans California. Each state's full growing guide is linked on this page.
What other growing regions cover the same states?
Pacific Northwest, California Central Valley, Sacramento Valley, Sierra Nevada Foothills, Sonoran Desert, and California Delta share at least one state with the San Joaquin Valley. Growing regions overlap and interlock — a single address can sit inside more than one, which is why the precise read is always the parcel, not the region.
What this page reads at the San Joaquin Valley’s own scale
6 of the readings below were taken at the San Joaquin Valley's own scale — the zone 9a-9b band across its footprint, a median 320-day season across its 8 counties and 32,386 documented federal contamination records across its 8 counties, 8,118 of them in Kern County alone; one is borrowed from a wider read, named and linked below.
Measured here
- The USDA hardiness band 9a-9b aggregated across all 8 counties in the footprintUSDA PHZM 2023
- The boundary itself — the 8 counties this region is curated fromGrowable Ground subregion registry
- The growing character that makes this region distinct from the states it crossesGrowable Ground subregion registry
- The 28°F season across the footprint — the middle half of its 8 counties run 315 to 322 frost-free days, median 320NOAA Regional Climate Centers ACIS, 1991-2020
- The federal contamination record over the whole footprint — 32,386 documented federal contamination records across its 8 counties, 8,118 of them in Kern County aloneEPA, USGS and USDA federal site records
- The soil order mix across the footprint — 28% Entisols, topsoil pH 5.8–8.3, area-weighted across its 8 mapped countiesUSDA NRCS SSURGO
Inherited from a wider read
- The candidate plant list — its state's curated sets, merged and filtered to zones 9a-9bfrom California
What this page can’t tell you
- Which end of the 7-day range your ground sits at — 315 days at one extreme, 322 at the other, decided mostly by elevationfrost dates explained →
- Which of those soils your own ground sits on — the survey maps them county-wide, and they change across a drivewaysoil types explained →
- The soil pH, drainage, sun hours, and frost pockets on one specific lotwhy one lot differs from the next →
Explore the San Joaquin Valley
State growing guides
Counties in this region
Other growing regions across California
The maritime Northwest west of the Cascade crest — mild, wet winters and dry summers behind berries, tree fruit, and lush cool-season gardens. (Union of the west-side ecoregions.)
A vast flat alluvial trough with hot dry summers and rich soils — one of the most productive agricultural regions on earth, from almonds and stone fruit to row crops.
The cooler, wetter northern half of the Central Valley — rice, walnuts, tomatoes, and orchard fruit on rich alluvial bottomland.
California's Gold Country foothills — rocky, well-drained slopes and warm days that suit wine grapes, olives, and Mediterranean orchard crops.
A warm desert of saguaro and palo verde with mild winters that allow desert citrus, dates, and prickly pear alongside intensive irrigated gardening.
Where the Sacramento and San Joaquin rivers braid into a maze of levee-ringed islands, the afternoon "Delta breeze" draws cool marine air off San Francisco Bay through the Carquinez Strait — tempering the interior valley's heat and stretching the frost-free season past 330 days in the western Delta (Solano and Contra Costa counties, per county_data.json). Behind the levees lie the black organic peat and muck soils of the reclaimed islands, the ground that made this California's historic Bartlett-pear and asparagus country and now grows cool-loving Clarksburg-AVA wine grapes like Chenin Blanc. It is the one corner of the Central Valley where a maritime influence, not just the sun, sets the growing rules.