Dewey-Humboldt, Arizona, sits in USDA hardiness zone 8a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Well-matched crops include cabbage, fig, california poppy, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Dewey-Humboldt, 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 Dewey-Humboldt 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 Dewey-Humboldt — soil, climate, flood, and parcel records. How we handle your address.
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Dewey-Humboldt — the short answer
Dewey-Humboldt, Arizona: USDA zone 8a, about 229 days between hard freezes, across 12K acres of town.
- USDA zone
- 8a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 9
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~229
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 12K 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 8a is Dewey-Humboldt's average, not your lot's — a low corner or a tree line moves it. Against Dewey-Humboldt's 229-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Dewey-Humboldt
Each reading below is measured for Dewey-Humboldt itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredDewey-Humboldt runs about 229 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredDewey-Humboldt sits in USDA hardiness zone 8a.
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 Dewey-Humboldt is in
Dewey-Humboldt sits in the Arizona/New Mexico Mountains — EPA Level III, inside the wider Temperate Sierras. That is read at Dewey-Humboldt's own centroid rather than borrowed from Yavapai County.
What Grows in Dewey-Humboldt
Every plant below cleared Dewey-Humboldt's own zone 8a and its 229-day season. Each card opens that plant's Arizona profile. How we score.
Is it too late to plant in Dewey-Humboldt?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Feb 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 25 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 9 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Documented around Dewey-Humboldt
Survey cells within 31 miles of Dewey-Humboldt checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 298 miles off. What to watch for.
What's on the federal record near Dewey-Humboldt
Closest first, within ~10 miles of Dewey-Humboldt. Listing isn't leaking, and distance isn't exposure.
- Brown ShaftMining · 1800 ft
- Iron King Extension Patented 1855Mining · 0.7 mi
- IRONITE PRODUCTS CO.Toxics Release Inventory · 0.9 mi
- HUMBOLDT UNIFIED SCHOOL DISTRICT #22Underground Storage Tanks · 0.9 mi
- RED STAR GENERAL STOREUnderground Storage Tanks · 0.9 mi
- FORMER FLICKS & SUBSUnderground Storage Tanks · 1.0 mi
- BILLY JACK'S SALONUnderground Storage Tanks · 1.0 mi
- HUMBOLDT MARKETUnderground Storage Tanks · 1.0 mi
- HUMBOLDT ELEMENTARY SCHOOL BUS YARDUnderground Storage Tanks · 1.1 mi
- Iron King TailingsMining · 1.1 mi
- Iron King MineMining · 1.1 mi
- Iron King PropertyMining · 1.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Dewey-Humboldt'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 Dewey-Humboldt.
Sources Checked
within ~10 miles of Dewey-Humboldt
Severity Distribution
within ~10 miles of Dewey-Humboldt
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Dewey-Humboldt, Mining runs higher than the national average — 191 sites within ~10 miles of Dewey-Humboldt. 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 Dewey-Humboldt
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 Dewey-Humboldt average
Your land is one point inside Dewey-Humboldt
Everything above resolves to Dewey-Humboldt as a whole — one PHZM band and one 28°F frost record, read across 12K 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 Dewey-Humboldt Average
Dewey-Humboldt Average
- ●USDA Zones 8a, averaged across Dewey-Humboldt
- ●One soil character for all of Dewey-Humboldt
- ●Frost dates read at Dewey-Humboldt's scale: Mar 25 to Nov 9
YOUR Parcel
- ✓Your exact zone, not Dewey-Humboldt's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Dewey-Humboldt
Pull a site-specific report for your exact address in Dewey-Humboldt, Arizona — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Dewey-Humboldt averages can't show:
We read public map data around Dewey-Humboldt — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Dewey-Humboldt average
How we know this about Dewey-Humboldt
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 Dewey-Humboldt’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 Dewey-Humboldt
When does frost risk typically end in Dewey-Humboldt?
The last hard freeze (28°F) in Dewey-Humboldt typically lands around Mar 25, 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 Apr 15.
When is the first frost in Dewey-Humboldt?
The first hard freeze (28°F) in Dewey-Humboldt typically arrives around Nov 9, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 26, so the watching starts about Oct 10 — about 229 days after the spring freeze cleared.
How long is the growing season in Dewey-Humboldt?
Measured between 28°F hard freezes, Dewey-Humboldt sees about 229 frost-free days — roughly Mar 25 through Nov 9, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 15 to Oct 26, about 194 days.
Is the soil safe to grow vegetables in Dewey-Humboldt?
The federal record around Dewey-Humboldt runs heavier than most — 320 documented sites, mostly Mining entries (191), the nearest Mining record about 0.3 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 Dewey-Humboldt?
From about Oct 10 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 Nov 9 (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 Nov 9. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Dewey-Humboldt's scale — its 8a band and its 229-day season. Your yard writes its own version of Dewey-Humboldt'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 Dewey-Humboldt’s own scale
7 of the readings below were taken at Dewey-Humboldt's own scale — its own ~229-day season between 28°F freezes, the 12,028 acres it covers and 320 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Dewey-Humboldt's own USDA hardiness band, zones 8aUSDA PHZM 2023
- Dewey-Humboldt's own 28°F hard-freeze dates, about Mar 25 and Nov 9 and the ~229-day span between themNOAA 1991–2020 Climate Normals
- 320 documented contamination sites on the federal record near Dewey-Humboldt, the closest Mining record about 0.3 miles out from the town centreFederal environmental registers
- Dewey-Humboldt's boundary and the 12,028 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~229-day seasonGrowable Ground crop-matching engine
- The ecoregion at Dewey-Humboldt's own centroid, the Arizona/New Mexico MountainsUS EPA Level III Ecoregions
- Lanternfly survey cells around Dewey-Humboldt checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Dewey-Humboldt's 12,028 acres read through its county's SSURGO summaryfrom Yavapai County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Yavapai County
- The growing challenges every Arizona grower plans around — written at state scale, so they stay on the state guidefrom Arizona
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Yavapai County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Dewey-Humboldt's 12,028 acreswhy one lot differs from the next →
- Which side of Dewey-Humboldt you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 12,028 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Mining record about 0.3 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 Dewey-Humboldt-wide figureread your own land →
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