Johnsville, California, sits in USDA hardiness zone 7a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Crops well matched to these conditions include cabbage, pawpaw, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Johnsville, 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 Johnsville 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 Johnsville — soil, climate, flood, and parcel records. How we handle your address.
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Johnsville — the short answer
Johnsville, California: USDA zone 7a, about 170 days between hard freezes, across 9K acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 11
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~170
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 9K 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 7a is Johnsville's average, not your lot's — a low corner or a tree line moves it. Against Johnsville's 170-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Johnsville
Each reading below is measured for Johnsville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredJohnsville runs about 170 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
MeasuredJohnsville sits in USDA hardiness zone 7a.
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 Johnsville is in
Johnsville sits in the Sierra Nevada — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Johnsville's own centroid rather than borrowed from Plumas County.
What Grows in Johnsville
Every plant below cleared Johnsville's own zone 7a and its 170-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in Johnsville?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Apr 13; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 28 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
What's on the federal record near Johnsville
Closest first, within ~10 miles of Johnsville. Listing isn't leaking, and distance isn't exposure.
- PLUMAS EUREKA STATE HISTORIC PARKSuperfund · 0.6 mi
- CALIFORNIA STATE PARKS PLUMAS EUREKA SPBrownfields · 0.6 mi
- Plumas-Eureka MineMining · 0.9 mi
- Plumas-EurekaMining · 1.0 mi
- LakinMining · 1.1 mi
- Jamison MineMining · 2.0 mi
- USDA USFS R05 BECKWOURTH RANGER DISTRICTBrownfields · 3.6 mi
- Graeagle ChevronUnderground Storage Tanks · 4.3 mi
- PACIFIC BELLBrownfields · 4.4 mi
- GRAEAGLE CHEVRONBrownfields · 4.4 mi
- PLUMAS COUNTY PUBLIC WORKSBrownfields · 4.4 mi
- PLUMAS COUNTYBrownfields · 4.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Johnsville'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 Johnsville.
Total Sites
31
within ~10 miles of Johnsville
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Johnsville
Severity Distribution
within ~10 miles of Johnsville
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Johnsville, Mining runs higher than the national average — 17 sites within ~10 miles of Johnsville. 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 Johnsville
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 Johnsville average
Your land is one point inside Johnsville
Everything above resolves to Johnsville as a whole — one PHZM band and one 28°F frost record, read across 9K 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 Johnsville Average
Johnsville Average
- ●USDA Zones 7a, averaged across Johnsville
- ●One soil character for all of Johnsville
- ●Frost dates read at Johnsville's scale: May 11 to Oct 28
YOUR Parcel
- ✓Your exact zone, not Johnsville's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Johnsville
Pull a site-specific report for your exact address in Johnsville, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Johnsville averages can't show:
We read public map data around Johnsville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Johnsville average
How we know this about Johnsville
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 Johnsville’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 Johnsville
When does frost risk typically end in Johnsville?
The last hard freeze (28°F) in Johnsville typically lands around May 11, 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 1.
When is the first frost in Johnsville?
The first hard freeze (28°F) in Johnsville typically arrives around Oct 28, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 14, so the watching starts about Sep 28 — about 170 days after the spring freeze cleared.
How long is the growing season in Johnsville?
Measured between 28°F hard freezes, Johnsville sees about 170 frost-free days — roughly May 11 through Oct 28, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 1 to Oct 14, about 135 days.
Is the soil safe to grow vegetables in Johnsville?
The federal record around Johnsville is a meaningful one — 31 documented sites, mostly Mining entries (17), the nearest Superfund record about 0.6 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 Johnsville?
From about Sep 28 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 Oct 28 (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 Oct 28. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Johnsville's scale — its 7a band and its 170-day season. Your yard writes its own version of Johnsville'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 Johnsville’s own scale
6 of the readings below were taken at Johnsville's own scale — its own ~170-day season between 28°F freezes, the 8,806 acres it covers and 31 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Johnsville's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Johnsville's own 28°F hard-freeze dates, about May 11 and Oct 28 and the ~170-day span between themNOAA 1991–2020 Climate Normals
- 31 documented contamination sites on the federal record near Johnsville, the closest Superfund record about 0.6 miles out from the town centreFederal environmental registers
- Johnsville's boundary and the 8,806 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~170-day seasonGrowable Ground crop-matching engine
- The ecoregion at Johnsville's own centroid, the Sierra NevadaUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Johnsville's 8,806 acres read through its county's SSURGO summaryfrom Plumas County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Plumas 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 Plumas County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Johnsville's 8,806 acreswhy one lot differs from the next →
- Which side of Johnsville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 8,806 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Superfund record about 0.6 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 Johnsville-wide figureread your own land →