Three Rivers, California, sits in USDA hardiness zone 10a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
The conditions favor okra, meyer lemon, california poppy, and artichoke, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Three Rivers, 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 Three Rivers 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 Three Rivers — soil, climate, flood, and parcel records. How we handle your address.
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Three Rivers — the short answer
Three Rivers, California: USDA zone 10a, about 320 days between hard freezes, across 20K acres of town.
- USDA zone
- 10a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 24
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Dec 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~320
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 20K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 10a is Three Rivers's average, not your lot's — a low corner or a tree line moves it. Against Three Rivers's 320-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Three Rivers
Each reading below is measured for Three Rivers itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredThree Rivers runs about 320 days between hard freezes — 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
MeasuredThree Rivers 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 Three Rivers is in
Three Rivers sits in the Central California Foothills and Coastal Mountains — EPA Level III, inside the wider Mediterranean California. That is read at Three Rivers's own centroid, and it is not what its county reads: Tulare County is mostly Sierra Nevada. The wider page above you is answering a different question about different ground.
What Grows in Three Rivers
Every plant below cleared Three Rivers's own zone 10a and its 320-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in Three Rivers?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. 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 24 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 10 — 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 Three Rivers
Closest first, within ~10 miles of Three Rivers. Listing isn't leaking, and distance isn't exposure.
- AT&T MOBILITYBrownfields · 1.0 mi
- 017S029E17E001MNitrate · 1.1 mi
- 017S028E24C001MNitrate · 1.2 mi
- THREE RIVERS UNION SCHOOL DISTRICTBrownfields · 1.2 mi
- DONALD W MOSLEY DDSBrownfields · 1.3 mi
- THREE RIVERS CHEVRONUnderground Storage Tanks · 1.3 mi
- THREE RIVERS MARKETUnderground Storage Tanks · 1.4 mi
- L.E. BRITTEN CONSTRUCTIONBrownfields · 1.5 mi
- 017S028E25D001MNitrate · 1.6 mi
- KAWEAH 1Brownfields · 1.9 mi
- TULARE COUNTY - ENVIRONMENTAL HEALHBrownfields · 2.1 mi
- TULARE COUNTY - ENVIRONMENTAL HEALTHBrownfields · 2.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Three Rivers'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 Three Rivers.
Total Sites
43
within ~10 miles of Three Rivers
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Three Rivers
Severity Distribution
within ~10 miles of Three Rivers
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Three Rivers, two things run higher than the national average within ~10 miles of Three Rivers — Mining (5 sites) and Nitrate (12 sites). That's not a problem with your land — it's information about it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Three Rivers
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 Three Rivers average
Your land is one point inside Three Rivers
Everything above resolves to Three Rivers as a whole — one PHZM band and one 28°F frost record, read across 20K acres. 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 Three Rivers Average
Three Rivers Average
- ●USDA Zones 10a, averaged across Three Rivers
- ●One soil character for all of Three Rivers
- ●Frost dates read at Three Rivers's scale: Jan 24 to Dec 10
YOUR Parcel
- ✓Your exact zone, not Three Rivers's 10a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Three Rivers
Pull a site-specific report for your exact address in Three Rivers, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Three Rivers averages can't show:
We read public map data around Three Rivers — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Three Rivers average
How we know this about Three Rivers
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 Three Rivers’s own record; 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 Three Rivers
When does frost risk typically end in Three Rivers?
The last hard freeze (28°F) in Three Rivers typically lands around Jan 24, 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 14.
When is the first frost in Three Rivers?
The first hard freeze (28°F) in Three Rivers typically arrives around Dec 10, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 26, so the watching starts about Nov 10 — about 320 days after the spring freeze cleared.
How long is the growing season in Three Rivers?
Measured between 28°F hard freezes, Three Rivers sees about 320 frost-free days — roughly Jan 24 through Dec 10, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 14 to Nov 26, about 285 days.
Is the soil safe to grow vegetables in Three Rivers?
The federal record around Three Rivers is a meaningful one — 43 documented sites, mostly Brownfields entries (19), the nearest Brownfields record about 1.0 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 Three Rivers?
From about Nov 10 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 10 (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 10. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Three Rivers's scale — its 10a band and its 320-day season. Your yard writes its own version of Three Rivers'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 Three Rivers’s own scale
6 of the readings below were taken at Three Rivers's own scale — its own ~320-day season between 28°F freezes, the 19,829 acres it covers and 43 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Three Rivers's own USDA hardiness band, zones 10aUSDA PHZM 2023
- Three Rivers's own 28°F hard-freeze dates, about Jan 24 and Dec 10 and the ~320-day span between themNOAA 1991–2020 Climate Normals
- 43 documented contamination sites on the federal record near Three Rivers, the closest Brownfields record about 1.0 miles out from the town centreFederal environmental registers
- Three Rivers's boundary and the 19,829 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 10a and a ~320-day seasonGrowable Ground crop-matching engine
- Three Rivers sits in the Central California Foothills and Coastal Mountains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Three Rivers's 19,829 acres read through its county's SSURGO summaryfrom Tulare County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Tulare 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 Tulare County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Three Rivers's 19,829 acreswhy one lot differs from the next →
- Which side of Three Rivers you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 19,829 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 1.0 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 Three Rivers-wide figureread your own land →
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