Del Norte County, in California, sits in USDA hardiness zone 9a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Growers here do well with artichoke, fig, california poppy, and cabbage — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Del Norte County holds more than one microclimate.
Soils and elevations shift across Del Norte 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 Del Norte County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Del Norte County — the short answer
Del Norte County, California: USDA zone 9a, about 293 days between hard freezes, across 644K acres.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 16
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Dec 6
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~293
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 644K 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 Del Norte County's average, not your lot's — a low corner or a tree line moves it. Against Del Norte County's 293-day season, see what your own ground reads.
Heat and winter chill in Del Norte County
Across a year, Del Norte County accumulates about 2,249 growing degree days above 50°F, about 1,508 fewer than the middle California county — ahead of 9 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 2,064 hours below 45°F, 877 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 Del Norte County
Across Del Norte County, the ground is predominantly Ultisols, where Slidecreek, Coppercreek, and Sasquatch are the most extensive named soil series. The soil is generally well drained with a gravelly loam surface. Topsoil pH runs about 5.0–5.6, strongly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Ultisols
Drainage
Well drained
Hydric soils
10%
Soil still varies lot by lot — soil types explained.
How the ground varies across Del Norte County
The USDA soil survey maps 76% of Del Norte County as well drained — but another 21% drains differently: 6% moderately well drained, 6% somewhat excessively drained.
Slidecreek is the most extensive named soil at 10% of mapped acres, then Coppercreek (9%) and Sasquatch (7%).
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 Del Norte County
Each reading below is measured for Del Norte 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 Del Norte 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 Del Norte County runs about pH 5.0–5.6, on the acidic side.
Blueberries, potatoes, and rhododendrons thrive in it, but most vegetables start locking out nutrients below about pH 6.0 and grow pale and stunted no matter how much you feed them.
A measured lime application raises pH for the crops that need it — but test first, because the right rate depends on your own soil, not the county average.
USDA NRCS SSURGO
Season length
MeasuredDel Norte County runs about 293 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
MeasuredDel Norte 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 Del Norte County is in
Del Norte County spans 2 EPA Level III ecoregions — Klamath Mountains/California High North Coast Range (71%) and Coast Range (30%). 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 Del Norte County
We scored all 1,086 plants against Del Norte County's own USDA zone 9a and its own 293-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 Del Norte County?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Jan 19; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 16 (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. Here the calendar nearly circles: cool-season crops take the winter shift, and the next window is always close.
What gets applied to farmland in Del Norte County
USGS estimates 1,585 lb of Diuron on Del Norte County farmland in 2019, its largest by weight, ahead of Ethoprophos (1,333 lb) and Glyphosate (711 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 Del Norte County — and how to grow with it.
We checked the federal record across Del Norte County — 417 documented sites across 7 of the 9 source types we track.
The most significant on record: 4 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Del Norte 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 Del Norte County
Closest first, across Del Norte County. Listing isn't leaking, and distance isn't exposure.
- Billy Boy Hawkins, DivideMining · 1200 ft
- HawkinsMining · 1200 ft
- Contact ClaimMining · 1600 ft
- Fourth of JulyMining · 2200 ft
- George WhistonMining · 0.9 mi
- French HillMining · 1.2 mi
- Ora Anna Quartz MineMining · 1.5 mi
- Unnamed LocationMining · 3.0 mi
- CarlaMining · 3.1 mi
- UnknownMining · 3.2 mi
- RattlesnakeMining · 3.5 mi
- GilmoreMining · 3.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Del Norte 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 Del Norte County.
Sources Checked
across Del Norte County
Severity Distribution
across Del Norte County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Del Norte County, Mining runs higher than the national average — 295 sites across Del Norte County. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Del Norte 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 Del Norte County average
Your land is one point inside Del Norte County
Everything above resolves to Del Norte County as a whole — one PHZM band and one county frost record, read across 644K 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 Del Norte County Average
Del Norte County Average
- ●USDA Zones 9a, averaged across Del Norte County
- ●One soil character for all of Del Norte County
- ●Frost dates read at Del Norte County's scale: Feb 16 to Dec 6
YOUR Parcel
- ✓Your exact zone, not Del Norte County's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Del Norte County
Pull a site-specific report for your exact address in Del Norte County, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Del Norte County averages can't show:
We read public map data around Del Norte County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Del Norte County average
How we know this about Del Norte 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 Del Norte County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Del Norte County
When does frost risk typically end in Del Norte County?
The last hard freeze (28°F) in Del Norte County typically lands around Feb 16, 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 9.
How long is the growing season in Del Norte County?
Measured between 28°F hard freezes, Del Norte County sees about 293 frost-free days — roughly Feb 16 through Dec 6, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 9 to Nov 22, about 258 days.
Is the soil safe to grow vegetables in Del Norte County?
The federal record around Del Norte County runs heavier than most — 417 documented sites, mostly Mining entries (295), the nearest Mining record about 0.2 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 Del Norte County's scale — its 9a band and its 293-day season. Your yard writes its own version of Del Norte 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 Del Norte County’s own scale
8 of the readings below were taken at Del Norte County's own scale — its own ~293-day span between 28°F freezes, the 3 most extensive soil series mapped here and 417 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Del Norte County's own USDA hardiness band, zones 9aUSDA PHZM 2023
- Del Norte County's own 28°F hard-freeze dates and its ~293-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Del Norte CountyUSDA NRCS SSURGO
- 417 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Mining record about 0.2 miles outFederal environmental registers
- Del Norte County's boundary and the 643,968 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~293-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Del Norte County spans, Klamath Mountains/California High North Coast Range the largestUS EPA Level III Ecoregions
- Which agricultural compounds go onto Del Norte 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 Del Norte County — the ~293 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 Del Norte County's 643,968 acreswhy one lot differs from the next →
- Which of those 417 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 Del Norte Countyread your own land →