White Hills, Arizona, 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.
These conditions suit artichoke, fig, california poppy, and cabbage — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in White Hills, 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 White Hills 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 White Hills — soil, climate, flood, and parcel records. How we handle your address.
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White Hills — the short answer
White Hills, Arizona: USDA zone 9a, about 242 days between hard freezes, across 33K acres of town.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 21
- Mohave County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 18
- Mohave County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~242
- Mohave County normal — NOAA 1991–2020, nearest to this town
- Town area
- 33K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are Mohave County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9a is White Hills's average, not your lot's — a low corner or a tree line moves it. Against White Hills's 242-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in White Hills
Each reading below is measured for White Hills itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsWhite Hills runs about 242 days between hard freezes (read from Mohave County, the closest normal to White Hills) — 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
MeasuredWhite Hills 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 White Hills is in
White Hills sits in the Mojave Basin and Range — EPA Level III, inside the wider North American Deserts. That is read at White Hills's own centroid rather than borrowed from Mohave County.
What Grows in White Hills
Every plant below cleared White Hills's own zone 9a and its 242-day season. Each card opens that plant's Arizona profile. How we score.
Is it too late to plant in White Hills?
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 21; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 18 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
What's on the federal record near White Hills
Closest first, within ~10 miles of White Hills. Listing isn't leaking, and distance isn't exposure.
- Norma MineMining · 1.3 mi
- B-27-20 09ADD1Nitrate · 1.6 mi
- B-27-20 09AAA1Nitrate · 1.9 mi
- B-27-20 29AAB1Nitrate · 2.4 mi
- Big Ledge and HelenaMining · 3.5 mi
- B-27-19 17AAA1Nitrate · 4.1 mi
- CALPORTLAND WHITE HILLS FACILITYToxics Release Inventory · 4.5 mi
- CARIOCA SHELLUnderground Storage Tanks · 4.5 mi
- B-27-21 25BAANitrate · 4.6 mi
- B-27-21 13CCDNitrate · 4.7 mi
- OASIS SHELLUnderground Storage Tanks · 4.8 mi
- B-28-21 26BBD1Nitrate · 7.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from White Hills'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 White Hills.
Total Sites
28
within ~10 miles of White Hills
Risk Level
Elevated
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of White Hills
Severity Distribution
within ~10 miles of White Hills
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around White Hills, two things run higher than the national average within ~10 miles of White Hills — Mining (9 sites) and Nitrate (16 sites). 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.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in White Hills
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 White Hills average
Your land is one point inside White Hills
Everything above resolves to White Hills as a whole — one PHZM band, read across 33K acres, with hard-freeze dates borrowed from Mohave County’s record because no 30-year normal resolves at this town’s own centroid. 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 White Hills Average
White Hills Average
- ●USDA Zones 9a, averaged across White Hills
- ●One soil character for all of White Hills
- ●Frost dates read at White Hills's scale: Mar 21 to Nov 18
YOUR Parcel
- ✓Your exact zone, not White Hills's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in White Hills
Pull a site-specific report for your exact address in White Hills, Arizona — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that White Hills averages can't show:
We read public map data around White Hills — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the White Hills average
How we know this about White Hills
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 Mohave County’s record, because none resolves here; 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 White Hills
When does frost risk typically end in White Hills?
The last hard freeze (28°F) in White Hills typically lands around Mar 21, 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 11.
When is the first frost in White Hills?
The first hard freeze (28°F) in White Hills typically arrives around Nov 18, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 4, so the watching starts about Oct 19 — about 242 days after the spring freeze cleared.
How long is the growing season in White Hills?
Measured between 28°F hard freezes, White Hills sees about 242 frost-free days — roughly Mar 21 through Nov 18, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 11 to Nov 4, about 207 days.
Is the soil safe to grow vegetables in White Hills?
The federal record around White Hills is a meaningful one — 28 documented sites, mostly Nitrate entries (16), the nearest Mining record about 1.3 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 White Hills?
From about Oct 19 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 18 (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 18. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at White Hills's scale — its 9a band and its 242-day season. Your yard writes its own version of White Hills'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 White Hills’s own scale
5 of the readings below were taken at White Hills's own scale — the 33,230 acres it covers and 28 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- White Hills's own USDA hardiness band, zones 9aUSDA PHZM 2023
- 28 documented contamination sites on the federal record near White Hills, the closest Mining record about 1.3 miles out from the town centreFederal environmental registers
- White Hills's boundary and the 33,230 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~242-day seasonGrowable Ground crop-matching engine
- The ecoregion at White Hills's own centroid, the Mojave Basin and RangeUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — White Hills has no normal of its own, so its county's is the closest measured readfrom Mohave County
- Soil character — no town-scale survey exists, so White Hills's 33,230 acres read through its county's SSURGO summaryfrom Mohave County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Mohave 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 Mohave County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among White Hills's 33,230 acreswhy one lot differs from the next →
- Which side of White Hills you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 33,230 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Mining record about 1.3 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 White Hills-wide figureread your own land →
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