Tuolumne County, in California, sits in USDA hardiness zone 8a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Growers here do well with cabbage, fig, california poppy, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Tuolumne County lies within the Sierra Nevada Foothills — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Tuolumne County holds more than one microclimate.
Soils and elevations shift across Tuolumne County, so your frost dates and drainage aren't the county average. 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 Tuolumne County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Tuolumne County — the short answer
Tuolumne County, California: USDA zone 8a, about 183 days between hard freezes, across 1.4M acres.
- USDA zone
- 8a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 5
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 4
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~183
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 1.4M acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 8a is Tuolumne County's average, not your lot's — a low corner or a tree line moves it. Against Tuolumne County's 183-day season, see what your own ground reads.
Heat in Tuolumne County
Across a year, Tuolumne County accumulates about 1,744 growing degree days above 50°F, about 2,013 fewer than the middle California county — ahead of 6 of California’s 57 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Tuolumne County
Across Tuolumne County, the ground is predominantly Alfisols, where Loafercreek, Canisrocks, and Nedsgulch are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 5.8–6.2, moderately acidic. Rainfall drains through hydrologic group D soils.
Soil order
Alfisols
Drainage
Well drained
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Tuolumne County
The USDA soil survey maps 59% of Tuolumne County as well drained — but another 25% drains differently: 15% excessively drained, 9% somewhat excessively drained.
Loafercreek is the most extensive named soil at 7% of mapped acres, then Canisrocks (5%) and Nedsgulch (5%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Tuolumne County
Each reading below is measured for Tuolumne County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Tuolumne County are well drained, in hydrologic group D — ground that drains quickly.
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
MeasuredTopsoil across Tuolumne County runs about pH 5.8–6.2, close to neutral.
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
Season length
MeasuredTuolumne County runs about 183 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredTuolumne County sits in USDA hardiness zone 8a.
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 Tuolumne County is in
Tuolumne County spans 2 EPA Level III ecoregions — Sierra Nevada (84%) and Central California Foothills and Coastal Mountains (16%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Tuolumne County
We scored all 1,086 plants against Tuolumne County's own USDA zone 8a and its own 183-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's California profile.
Is it too late to plant in Tuolumne County?
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 Apr 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 4 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
Documented around Tuolumne County
- monarch butterfly2 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Tuolumne County
USGS estimates 120 lb of Glyphosate on Tuolumne County farmland in 2019, its largest by weight, ahead of Triclopyr (12 lb) and Chlorantraniliprole (5 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Tuolumne County — and how to grow with it.
We checked the federal record across Tuolumne County — 536 documented sites across 7 of the 9 source types we track.
The most significant on record: 6 Superfund sites (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Tuolumne County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Tuolumne County
Closest first, across Tuolumne County. Listing isn't leaking, and distance isn't exposure.
- Casa MaderaMining · 5.1 mi
- WashingtonMining · 8.8 mi
- GemMining · 9.6 mi
- 003N017E02G001MNitrate · 10.5 mi
- CALIF SOUTHERN BAPTIST CONVENTION/JENNESBrownfields · 10.6 mi
- ERIC BREWERBrownfields · 10.6 mi
- CCSF-R&P CAMP MATHERBrownfields · 10.6 mi
- Sierra Energy #40Underground Storage Tanks · 10.9 mi
- TOMS SIERRA CO INC/DBA SIERRA ENERGY #40Brownfields · 10.9 mi
- TIMBERLINE ENVIRONMENTAL SERVICESBrownfields · 10.9 mi
- CALIFORNIA ALUMNI ASSOCIATIONBrownfields · 11.3 mi
- 001S018E13F001MNitrate · 11.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Tuolumne County'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 Tuolumne County.
Total Sites
536
across Tuolumne County
Risk Level
High
Highest-severity
6 Superfund sites (none NPL-listed)
Sources Checked
across Tuolumne County
Severity Distribution
across Tuolumne County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Tuolumne County, two things run higher than the national average across Tuolumne County — Mining (182 sites) and PFAS (5 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around 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.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Tuolumne County
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 Tuolumne County average
Your land is one point inside Tuolumne County
Everything above resolves to Tuolumne County as a whole — one PHZM band and one county frost record, read across 1.4M 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 county 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 county average.
Your Lot vs the Tuolumne County Average
Tuolumne County Average
- ●USDA Zones 8a, averaged across Tuolumne County
- ●One soil character for all of Tuolumne County
- ●Frost dates read at Tuolumne County's scale: May 5 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Tuolumne County's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Tuolumne County
Pull a site-specific report for your exact address in Tuolumne County, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Tuolumne County averages can't show:
We read public map data around Tuolumne County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Tuolumne County average
How we know this about Tuolumne County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Tuolumne County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Tuolumne County
When does frost risk typically end in Tuolumne County?
The last hard freeze (28°F) in Tuolumne County typically lands around May 5, 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 May 26.
How long is the growing season in Tuolumne County?
Measured between 28°F hard freezes, Tuolumne County sees about 183 frost-free days — roughly May 5 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 26 to Oct 21, about 148 days.
Is the soil safe to grow vegetables in Tuolumne County?
The federal record around Tuolumne County runs heavier than most — 536 documented sites, mostly Brownfields entries (294), the nearest Mining record about 5.1 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
Everything above is measured at Tuolumne County's scale — its 8a band and its 183-day season. Your yard writes its own version of Tuolumne County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads California's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Tuolumne County’s own scale
9 of the readings below were taken at Tuolumne County's own scale — its own ~183-day span between 28°F freezes, the 3 most extensive soil series mapped here and 536 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Tuolumne County's own USDA hardiness band, zones 8aUSDA PHZM 2023
- Tuolumne County's own 28°F hard-freeze dates and its ~183-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Tuolumne CountyUSDA NRCS SSURGO
- 536 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Mining record about 5.1 miles outFederal environmental registers
- Tuolumne County's boundary and the 1,421,382 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~183-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Tuolumne County spans, Sierra Nevada the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Tuolumne County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Tuolumne County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every California grower plans around — written at state scale, so they stay on the state guidefrom California
What this page can’t tell you
- How the season shifts across Tuolumne County — the ~183 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Tuolumne County's 1,421,382 acreswhy one lot differs from the next →
- Which of those 536 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Tuolumne Countyread your own land →