Campo Seco, California, sits in USDA hardiness zone 9b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Reliable performers under these conditions include okra, meyer lemon, california poppy, and artichoke; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Campo Seco, 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 Campo Seco 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 Campo Seco — soil, climate, flood, and parcel records. How we handle your address.
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Campo Seco — the short answer
Campo Seco, California: USDA zone 9b, about 288 days between hard freezes, across 835 acres of town.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 21
- Calaveras County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 6
- Calaveras County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~288
- Calaveras County normal — NOAA 1991–2020, nearest to this town
- Town area
- 835 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 Calaveras County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9b is Campo Seco's average, not your lot's — a low corner or a tree line moves it. Against Campo Seco's 288-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Campo Seco
Each reading below is measured for Campo Seco itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsCampo Seco runs about 288 days between hard freezes (read from Calaveras County, the closest normal to Campo Seco) — 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
MeasuredCampo Seco sits in USDA hardiness zone 9b.
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 Campo Seco is in
Campo Seco sits in the Central California Foothills and Coastal Mountains — EPA Level III, inside the wider Mediterranean California. That is read at Campo Seco's own centroid rather than borrowed from Calaveras County.
What Grows in Campo Seco
Every plant below cleared Campo Seco's own zone 9b and its 288-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in Campo Seco?
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 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's on the federal record near Campo Seco
Closest first, within ~10 miles of Campo Seco. Listing isn't leaking, and distance isn't exposure.
- EdnaMining · 2300 ft
- PENN MINESuperfund · 0.8 mi
- HolmesMining · 0.8 mi
- CaldwellMining · 0.9 mi
- Grey EagleMining · 1.0 mi
- Campo SecoMining · 1.0 mi
- ConstellationMining · 1.0 mi
- Penn MineMining · 1.0 mi
- PennMining · 1.1 mi
- Bell PrinceMining · 1.3 mi
- EBMUD - PARDEE CENTERBrownfields · 1.8 mi
- Missinger RanchMining · 1.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Campo Seco'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 Campo Seco.
Sources Checked
within ~10 miles of Campo Seco
Severity Distribution
within ~10 miles of Campo Seco
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Campo Seco, two things run higher than the national average within ~10 miles of Campo Seco — Mining (100 sites) and PFAS (5 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 Campo Seco
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 Campo Seco average
Your land is one point inside Campo Seco
Everything above resolves to Campo Seco as a whole — one PHZM band, read across 835 acres, with hard-freeze dates borrowed from Calaveras County’s record because no 30-year normal resolves at this town’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 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 Campo Seco Average
Campo Seco Average
- ●USDA Zones 9b, averaged across Campo Seco
- ●One soil character for all of Campo Seco
- ●Frost dates read at Campo Seco's scale: Feb 21 to Dec 6
YOUR Parcel
- ✓Your exact zone, not Campo Seco's 9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Campo Seco
Pull a site-specific report for your exact address in Campo Seco, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Campo Seco averages can't show:
We read public map data around Campo Seco — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Campo Seco average
How we know this about Campo Seco
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 Calaveras 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 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 Campo Seco
When does frost risk typically end in Campo Seco?
The last hard freeze (28°F) in Campo Seco 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.
When is the first frost in Campo Seco?
The first hard freeze (28°F) in Campo Seco typically arrives around Dec 6, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 22, so the watching starts about Nov 6 — about 288 days after the spring freeze cleared.
How long is the growing season in Campo Seco?
Measured between 28°F hard freezes, Campo Seco 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 Campo Seco?
The federal record around Campo Seco runs heavier than most — 281 documented sites, mostly Brownfields entries (117), 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.
How do I protect my plants from frost in Campo Seco?
From about Nov 6 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 6 (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 6. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Campo Seco's scale — its 9b band and its 288-day season. Your yard writes its own version of Campo Seco'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 Campo Seco’s own scale
5 of the readings below were taken at Campo Seco's own scale — the 835 acres it covers and 281 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Campo Seco's own USDA hardiness band, zones 9bUSDA PHZM 2023
- 281 documented contamination sites on the federal record near Campo Seco, the closest Mining record about 0.4 miles out from the town centreFederal environmental registers
- Campo Seco's boundary and the 835 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~288-day seasonGrowable Ground crop-matching engine
- The ecoregion at Campo Seco's own centroid, the Central California Foothills and Coastal MountainsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Campo Seco has no normal of its own, so its county's is the closest measured readfrom Calaveras County
- Soil character — no town-scale survey exists, so Campo Seco's 835 acres read through its county's SSURGO summaryfrom Calaveras County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Calaveras 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 Calaveras County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Campo Seco's 835 acreswhy one lot differs from the next →
- Which side of Campo Seco you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 835 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Mining record about 0.4 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 Campo Seco-wide figureread your own land →