Plumas County, in California, sits in USDA hardiness zone 7b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Expect cabbage, fig, california poppy, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Plumas County lies within the Sierra Nevada High Country / Eastern Sierra — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Plumas County holds more than one microclimate.
Soils and elevations shift across Plumas 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 Plumas County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Plumas County — the short answer
Plumas County, California: USDA zone 7b, about 158 days between hard freezes, across 1.6M acres.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 20
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 25
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~158
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 1.6M 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 7b is Plumas County's average, not your lot's — a low corner or a tree line moves it. Against Plumas County's 158-day season, see what your own ground reads.
One county, several growing seasons
Plumas County's hard-freeze record runs about 158 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: Indian Falls at about 207 days, Paxton at 207, Crescent Mills at 196 and Greenville at 196 (against the county's ~158).
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 ~158-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 in Plumas County
Across a year, Plumas County accumulates about 1,550 growing degree days above 50°F, about 2,207 fewer than the middle California county — ahead of 4 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 Plumas County
Across Plumas County, the ground is predominantly Mollisols, where Devada, Petescreek, and Ravendale are the most extensive named soil series. The soil is generally well drained with a gravelly loam surface. Topsoil pH runs about 6.3–7.0, neutral. Rainfall drains through hydrologic group C soils.
Soil order
Mollisols
Drainage
Well drained
Hydric soils
2%
Soil still varies lot by lot — soil types explained.
How the ground varies across Plumas County
The USDA soil survey maps 74% of Plumas County as well drained — but another 25% drains differently: 8% somewhat excessively drained, 7% moderately well drained.
Devada is the most extensive named soil at 5% of mapped acres, then Petescreek (4%) and Ravendale (3%).
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 Plumas County
Each reading below is measured for Plumas 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 Plumas 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 Plumas County runs about pH 6.3–7.0, 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
MeasuredPlumas County runs about 158 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
MeasuredPlumas County sits in USDA hardiness zone 7b.
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 Plumas County is in
Plumas County spans 2 EPA Level III ecoregions — Sierra Nevada (80%) and Cascades (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 Plumas County
We scored all 1,086 plants against Plumas County's own USDA zone 7b and its own 158-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 Plumas County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 22; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 20 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 25 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
Documented around Plumas County
- monarch butterfly6 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Plumas County
USGS estimates 357 lb of 2,4-d on Plumas County farmland in 2019, its largest by weight, ahead of Imazethapyr (32 lb) and Triclopyr (26 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 Plumas County — and how to grow with it.
We checked the federal record across Plumas County — 406 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.
Plumas 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 Plumas County
Closest first, across Plumas County. Listing isn't leaking, and distance isn't exposure.
- Rossi and Maine LodesMining · 3.4 mi
- OhioMining · 4.4 mi
- HinchmanMining · 4.8 mi
- Polar StarMining · 5.0 mi
- Iron DykeMining · 5.1 mi
- Iron DikeMining · 5.1 mi
- HANKS AUTOMOTIVEBrownfields · 5.2 mi
- Mountain LionMining · 5.2 mi
- Blue BellMining · 5.3 mi
- ANDREW FEINBLUM DBA SIERRA CYCLEBrownfields · 5.4 mi
- PilotMining · 5.5 mi
- SIERRA SUPER STOP #19Brownfields · 5.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Plumas 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 Plumas County.
Sources Checked
across Plumas County
Severity Distribution
across Plumas County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Plumas County, Mining runs higher than the national average — 188 sites across Plumas County. 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.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Plumas 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 Plumas County average
Your land is one point inside Plumas County
Everything above resolves to Plumas County as a whole — a county whose own towns’ 30-year records run 196 days between freezes in Crescent Mills to 207 in Paxton. 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 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 Plumas County Average
Plumas County Average
- ●USDA Zones 7b, averaged across Plumas County
- ●One soil character for all of Plumas County
- ●Frost dates read at Plumas County's scale: May 20 to Oct 25
YOUR Parcel
- ✓Your exact zone, not Plumas County's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Plumas County
Pull a site-specific report for your exact address in Plumas County, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Plumas County averages can't show:
We read public map data around Plumas County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Plumas County average
How we know this about Plumas 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 Plumas County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Plumas County
When does frost risk typically end in Plumas County?
The last hard freeze (28°F) in Plumas County typically lands around May 20, 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 Jun 10.
How long is the growing season in Plumas County?
Measured between 28°F hard freezes, Plumas County sees about 158 frost-free days — roughly May 20 through Oct 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 10 to Oct 11, about 123 days.
Is the soil safe to grow vegetables in Plumas County?
The federal record around Plumas County runs heavier than most — 406 documented sites, mostly Mining entries (188), the nearest Mining record about 3.4 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 Plumas County's scale — its 7b band and its 158-day season. Your yard writes its own version of Plumas 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 Plumas County’s own scale
9 of the readings below were taken at Plumas County's own scale — its own ~158-day span between 28°F freezes, the 3 most extensive soil series mapped here and 406 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Plumas County's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Plumas County's own 28°F hard-freeze dates and its ~158-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Plumas CountyUSDA NRCS SSURGO
- 406 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Mining record about 3.4 miles outFederal environmental registers
- Plumas County's boundary and the 1,633,958 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~158-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Plumas County spans, Sierra Nevada the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Plumas County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Plumas 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 Plumas County — the ~158 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 Plumas County's 1,633,958 acreswhy one lot differs from the next →
- Which of those 406 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 Plumas Countyread your own land →