Humboldt County, in Nevada, sits in USDA hardiness zone 6a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
The conditions favor cabbage, blackberry, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Humboldt County lies within the Humboldt River Corridor — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Humboldt County holds more than one microclimate.
Soils and elevations shift across Humboldt 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 Humboldt County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Humboldt County — the short answer
Humboldt County, Nevada: USDA zone 6a, about 161 days between hard freezes, across 6.2M acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 1
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 9
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~161
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 6.2M 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 6a is Humboldt County's average, not your lot's — a low corner or a tree line moves it. Against Humboldt County's 161-day season, see what your own ground reads.
Heat in Humboldt County
Across a year, Humboldt County accumulates about 2,429 growing degree days above 50°F, about 286 more than the middle Nevada county — ahead of 10 of Nevada’s 17 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 Humboldt County
Across Humboldt County, the ground is predominantly Aridisols, where Boton, Soughe, and Devada are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 7.2–8.5, slightly alkaline. Rainfall drains through hydrologic group D soils.
Soil order
Aridisols
Drainage
Well drained
Hydric soils
1%
Soil still varies lot by lot — soil types explained.
How the ground varies across Humboldt County
The USDA soil survey maps 80% of Humboldt County as well drained — but another 20% drains differently: 7% somewhat excessively drained, 4% somewhat poorly drained.
Boton is the most extensive named soil at 6% of mapped acres, then Soughe (3%) and Devada (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 Humboldt County
Each reading below is measured for Humboldt 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 Humboldt County are well drained, in hydrologic group D — 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 Humboldt County runs about pH 7.2–8.5, on the alkaline side.
Many vegetables cope, but acid-lovers like blueberries struggle, and iron and manganese lock up above about pH 7.5 — leaves yellow between the veins even in rich soil.
Elemental sulfur and generous organic matter lower pH slowly for the beds that need it; test first so you add only what the soil actually calls for.
USDA NRCS SSURGO
Season length
MeasuredHumboldt County runs about 161 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
MeasuredHumboldt County sits in USDA hardiness zone 6a.
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 Humboldt County is in
Humboldt County spans 2 EPA Level III ecoregions — Central Basin and Range (58%) and Northern Basin and Range (42%). 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 Humboldt County
We scored all 1,086 plants against Humboldt County's own USDA zone 6a and its own 161-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 Nevada profile.
Is it too late to plant in Humboldt County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 9 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
Documented around Humboldt County
- monarch butterfly26 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Humboldt County
USGS estimates 16,226 lb of Glyphosate on Humboldt County farmland in 2019, its largest by weight, ahead of Chlorpyrifos (4,541 lb) and Malathion (4,053 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 Humboldt County — and how to grow with it.
We checked the federal record across Humboldt County — 901 documented sites across 7 of the 9 source types we track.
The most significant on record: 9 Superfund sites (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Humboldt 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 Humboldt County
Closest first, across Humboldt County. Listing isn't leaking, and distance isn't exposure.
- 031 N41 E35 20A 1Nitrate · 3.2 mi
- 030B N41 E35 17A 1Nitrate · 3.6 mi
- 031 N42 E34 36BBBB1 Sod House-Quinn River WellNitrate · 4.7 mi
- 030B N41 E35 22DB 1Nitrate · 5.3 mi
- Vermillion ProspectMining · 5.5 mi
- VermillionMining · 5.5 mi
- 030B N41 E35 23CBC 1 Quinn River Well 2Nitrate · 5.6 mi
- Sleeper MineMining · 6.4 mi
- 031 N42 E34 20DBC 1 USGS - Test WellNitrate · 6.8 mi
- 030B N42 E34 30ABC 1 Indian Stock WellNitrate · 6.9 mi
- 030B N42 E35 19A 1Nitrate · 7.3 mi
- 033A N41 E36 06CB 1Nitrate · 8.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Humboldt 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 Humboldt County.
Total Sites
901
across Humboldt County
Risk Level
High
Highest-severity
9 Superfund sites (none NPL-listed)
Sources Checked
across Humboldt County
Severity Distribution
across Humboldt County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Humboldt County, Mining runs higher than the national average — 541 sites across Humboldt County. 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.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Humboldt 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 Humboldt County average
Your land is one point inside Humboldt County
Everything above resolves to Humboldt County as a whole — one PHZM band and one county frost record, read across 6.2M 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 Humboldt County Average
Humboldt County Average
- ●USDA Zones 6a, averaged across Humboldt County
- ●One soil character for all of Humboldt County
- ●Frost dates read at Humboldt County's scale: May 1 to Oct 9
YOUR Parcel
- ✓Your exact zone, not Humboldt County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Humboldt County
Pull a site-specific report for your exact address in Humboldt County, Nevada — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Humboldt County averages can't show:
We read public map data around Humboldt County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Humboldt County average
How we know this about Humboldt 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 Humboldt County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Humboldt County
When does frost risk typically end in Humboldt County?
The last hard freeze (28°F) in Humboldt County typically lands around May 1, 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 May 22.
How long is the growing season in Humboldt County?
Measured between 28°F hard freezes, Humboldt County sees about 161 frost-free days — roughly May 1 through Oct 9, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 22 to Sep 25, about 126 days.
Is the soil safe to grow vegetables in Humboldt County?
The federal record around Humboldt County runs heavier than most — 901 documented sites, mostly Mining entries (541), the nearest Nitrate record about 3.2 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 Humboldt County's scale — its 6a band and its 161-day season. Your yard writes its own version of Humboldt 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 Nevada's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Humboldt County’s own scale
9 of the readings below were taken at Humboldt County's own scale — its own ~161-day span between 28°F freezes, the 3 most extensive soil series mapped here and 901 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Humboldt County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Humboldt County's own 28°F hard-freeze dates and its ~161-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Humboldt CountyUSDA NRCS SSURGO
- 901 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 3.2 miles outFederal environmental registers
- Humboldt County's boundary and the 6,170,101 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~161-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Humboldt County spans, Central Basin and Range the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Humboldt County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Humboldt County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Nevada grower plans around — written at state scale, so they stay on the state guidefrom Nevada
What this page can’t tell you
- How the season shifts across Humboldt County — the ~161 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 Humboldt County's 6,170,101 acreswhy one lot differs from the next →
- Which of those 901 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 Humboldt Countyread your own land →