Calaveras County, in California, sits in USDA hardiness zone 9a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
A short list that earns its place here — artichoke, fig, california poppy, and cabbage — with any one site's soil, sun, and drainage making the final cut.
Calaveras 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
Calaveras County holds more than one microclimate.
Soils and elevations shift across Calaveras 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 Calaveras County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Calaveras County — the short answer
Calaveras County, California: USDA zone 9a, about 288 days between hard freezes, across 653K acres.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 21
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Dec 6
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~288
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 653K 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 9a is Calaveras County's average, not your lot's — a low corner or a tree line moves it. Against Calaveras County's 288-day season, see what your own ground reads.
One county, several growing seasons
Calaveras County's hard-freeze record runs about 288 days between freezes — but that is the county-wide average, and several towns inside it carry a markedly different season in their own 30-year record: Avery at about 246 days and Hathaway Pines at 246 (against the county's ~288).
Those are measured records, not estimates. If you garden in one of these pockets, plant against your own town's season rather than the county's ~288-day average.
NOAA Regional Climate Centers ACIS (1991–2020), 30-year daily minimum record. Only held-out towns carrying their own record are named — a town with no record of its own is absent rather than estimated, and a county with nothing qualifying shows no spread at all.
Heat and winter chill in Calaveras County
Across a year, Calaveras County accumulates about 3,780 growing degree days above 50°F, about 23 more than the middle California county — ahead of 30 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.
Winter banks about 1,637 hours below 45°F, 450 more than the California middle of 1,187. Chill is what tells a fruit tree its dormancy is over, and it is set by climate rather than by anything you can build.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Calaveras County
Across Calaveras County, the ground is predominantly Alfisols, where Loafercreek, Nedsgulch, and Bonanza are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 6.0–6.5, slightly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Alfisols
Drainage
Well drained
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Calaveras County
The USDA soil survey maps 91% of Calaveras County as well drained — but another 4% drains differently: 3% excessively drained, 1% moderately well drained.
Loafercreek is the most extensive named soil at 12% of mapped acres, then Nedsgulch (8%) and Bonanza (6%).
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 Calaveras County
Each reading below is measured for Calaveras 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 Calaveras County are well drained, in hydrologic group C — 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 Calaveras County runs about pH 6.0–6.5, 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
MeasuredCalaveras County runs about 288 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
MeasuredCalaveras County 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 Calaveras County is in
Calaveras County spans 2 EPA Level III ecoregions — Central California Foothills and Coastal Mountains (52%) and Sierra Nevada (48%). 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 Calaveras County
We scored all 1,086 plants against Calaveras County's own USDA zone 9a and its own 288-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 Calaveras County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Jan 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 6 — long-season crops need about 90 days of runway, quick greens only 30. In a climate this gentle, “too late” hardly applies — the question becomes which crops prefer the cooler months ahead.
What gets applied to farmland in Calaveras County
USGS estimates 1,816 lb of Glyphosate on Calaveras County farmland in 2019, its largest by weight, ahead of Malathion (207 lb) and Tebuconazole (75 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 Calaveras County — and how to grow with it.
We checked the federal record across Calaveras County — 530 documented sites across 7 of the 9 source types we track.
The most significant on record: 5 Superfund sites (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Calaveras 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 Calaveras County
Closest first, across Calaveras County. Listing isn't leaking, and distance isn't exposure.
- Mar John Mines Co.Mining · 2200 ft
- WinchesterMining · 0.5 mi
- AlpineMining · 0.7 mi
- EAGLE AUTOMOTIVE EQUIPMENTBrownfields · 1.3 mi
- PAUL DE ANGELISBrownfields · 1.3 mi
- RITE OF PASSAGE/SIERRA RIDGE-SLOW SAND FILTERS & DISINFECTIONBrownfields · 1.6 mi
- CRAIG TRUCKING COBrownfields · 2.5 mi
- CHATOM VINEYARDSBrownfields · 2.6 mi
- Big John's Gas StationUnderground Storage Tanks · 2.6 mi
- CALAVERAS COUNTY-USED OIL COLLECTIONBrownfields · 2.6 mi
- BIG JOHN'SBrownfields · 2.6 mi
- PENN MINEBrownfields · 2.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Calaveras 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 Calaveras County.
Total Sites
530
across Calaveras County
Risk Level
High
Highest-severity
5 Superfund sites (none NPL-listed)
Sources Checked
across Calaveras County
Severity Distribution
across Calaveras County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Calaveras County, two things run higher than the national average across Calaveras County — Mining (245 sites) and PFAS (6 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.
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 Calaveras 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 Calaveras County average
Your land is one point inside Calaveras County
Everything above resolves to Calaveras County as a whole — one PHZM band and one county frost record, read across 653K 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 Calaveras County Average
Calaveras County Average
- ●USDA Zones 9a, averaged across Calaveras County
- ●One soil character for all of Calaveras County
- ●Frost dates read at Calaveras County's scale: Feb 21 to Dec 6
YOUR Parcel
- ✓Your exact zone, not Calaveras County's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Calaveras County
Pull a site-specific report for your exact address in Calaveras County, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Calaveras County averages can't show:
We read public map data around Calaveras County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Calaveras County average
How we know this about Calaveras 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 Calaveras County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Calaveras County
When does frost risk typically end in Calaveras County?
The last hard freeze (28°F) in Calaveras County typically lands around Feb 21, 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 Mar 14.
How long is the growing season in Calaveras County?
Measured between 28°F hard freezes, Calaveras County sees about 288 frost-free days — roughly Feb 21 through Dec 6, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 14 to Nov 22, about 253 days.
Is the soil safe to grow vegetables in Calaveras County?
The federal record around Calaveras County runs heavier than most — 530 documented sites, mostly Mining entries (245), the nearest Mining record about 0.4 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 Calaveras County's scale — its 9a band and its 288-day season. Your yard writes its own version of Calaveras 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 Calaveras County’s own scale
8 of the readings below were taken at Calaveras County's own scale — its own ~288-day span between 28°F freezes, the 3 most extensive soil series mapped here and 530 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Calaveras County's own USDA hardiness band, zones 9aUSDA PHZM 2023
- Calaveras County's own 28°F hard-freeze dates and its ~288-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Calaveras CountyUSDA NRCS SSURGO
- 530 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Mining record about 0.4 miles outFederal environmental registers
- Calaveras County's boundary and the 652,810 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~288-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Calaveras County spans, Central California Foothills and Coastal Mountains the largestUS EPA Level III Ecoregions
- Which agricultural compounds go onto Calaveras 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 Calaveras County — the ~288 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 Calaveras County's 652,810 acreswhy one lot differs from the next →
- Which of those 530 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 Calaveras Countyread your own land →