Wellton Hills, Arizona, sits in USDA hardiness zone 9b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
These conditions suit okra, meyer lemon, california poppy, and artichoke — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Wellton 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 Wellton 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 Wellton Hills — soil, climate, flood, and parcel records. How we handle your address.
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Wellton Hills — the short answer
Wellton Hills, Arizona: USDA zone 9b, about 316 days between hard freezes, across 409 acres of town.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 29
- Yuma County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 11
- Yuma County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~316
- Yuma County normal — NOAA 1991–2020, nearest to this town
- Town area
- 409 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 Yuma County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9b is Wellton Hills's average, not your lot's — a low corner or a tree line moves it. Against Wellton Hills's 316-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Wellton Hills
Each reading below is measured for Wellton Hills itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsWellton Hills runs about 316 days between hard freezes (read from Yuma County, the closest normal to Wellton Hills) — 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
MeasuredWellton Hills sits in USDA hardiness zone 9b.
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 Wellton Hills is in
Wellton Hills sits in the Sonoran Basin and Range — EPA Level III, inside the wider North American Deserts. That is read at Wellton Hills's own centroid rather than borrowed from Yuma County.
What Grows in Wellton Hills
Every plant below cleared Wellton Hills's own zone 9b and its 316-day season. Each card opens that plant's Arizona profile. How we score.
Is it too late to plant in Wellton 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 Jan 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jan 29 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 11 — 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.
Documented around Wellton Hills
Survey cells within 31 miles of Wellton Hills checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 180 miles off. What to watch for.
What's on the federal record near Wellton Hills
Closest first, within ~10 miles of Wellton Hills. Listing isn't leaking, and distance isn't exposure.
- 79907Nitrate · 2.2 mi
- WELLTON CHEVRONUnderground Storage Tanks · 2.5 mi
- Northern ProspectMining · 2.9 mi
- C-09-18 05DCB1Nitrate · 3.0 mi
- SOUTHERN PACIFIC TRANSPORTATION - WELLTON RAILROAD YRDUnderground Storage Tanks · 3.2 mi
- NUTRIEN AG SOLUTIONSUnderground Storage Tanks · 3.3 mi
- WESTERN FARM SERVICE, WELLTONBrownfields · 3.3 mi
- Wanamaker ProspectMining · 3.3 mi
- WELLTON SCALE - LOS ANGELES WAYUnderground Storage Tanks · 3.3 mi
- WELLTON ELEMENTARY SCHOOLUnderground Storage Tanks · 3.4 mi
- TOWN OF WELLTON - STORAGE FACILITYUnderground Storage Tanks · 3.4 mi
- Welltonia ProspectMining · 3.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Wellton 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 Wellton Hills.
Total Sites
65
within ~10 miles of Wellton Hills
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Wellton Hills
Severity Distribution
within ~10 miles of Wellton Hills
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Wellton Hills, two things run higher than the national average within ~10 miles of Wellton Hills — Mining (19 sites) and Nitrate (28 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 Wellton 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 Wellton Hills average
Your land is one point inside Wellton Hills
Everything above resolves to Wellton Hills as a whole — one PHZM band, read across 409 acres, with hard-freeze dates borrowed from Yuma 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 Wellton Hills Average
Wellton Hills Average
- ●USDA Zones 9b, averaged across Wellton Hills
- ●One soil character for all of Wellton Hills
- ●Frost dates read at Wellton Hills's scale: Jan 29 to Dec 11
YOUR Parcel
- ✓Your exact zone, not Wellton Hills's 9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Wellton Hills
Pull a site-specific report for your exact address in Wellton Hills, Arizona — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Wellton Hills averages can't show:
We read public map data around Wellton Hills — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Wellton Hills average
How we know this about Wellton 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 Yuma 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 Wellton Hills
When does frost risk typically end in Wellton Hills?
The last hard freeze (28°F) in Wellton Hills typically lands around Jan 29, 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 Feb 19.
When is the first frost in Wellton Hills?
The first hard freeze (28°F) in Wellton Hills typically arrives around Dec 11, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 27, so the watching starts about Nov 11 — about 316 days after the spring freeze cleared.
How long is the growing season in Wellton Hills?
Measured between 28°F hard freezes, Wellton Hills sees about 316 frost-free days — roughly Jan 29 through Dec 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 19 to Nov 27, about 281 days.
Is the soil safe to grow vegetables in Wellton Hills?
The federal record around Wellton Hills is a meaningful one — 65 documented sites, mostly Nitrate entries (28), the nearest Nitrate record about 2.2 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 Wellton Hills?
From about Nov 11 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 Dec 11 (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 Dec 11. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Wellton Hills's scale — its 9b band and its 316-day season. Your yard writes its own version of Wellton 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 Wellton Hills’s own scale
6 of the readings below were taken at Wellton Hills's own scale — the 409 acres it covers and 65 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Wellton Hills's own USDA hardiness band, zones 9bUSDA PHZM 2023
- 65 documented contamination sites on the federal record near Wellton Hills, the closest Nitrate record about 2.2 miles out from the town centreFederal environmental registers
- Wellton Hills's boundary and the 409 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~316-day seasonGrowable Ground crop-matching engine
- The ecoregion at Wellton Hills's own centroid, the Sonoran Basin and RangeUS EPA Level III Ecoregions
- Lanternfly survey cells around Wellton Hills checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- The 28°F hard-freeze dates — Wellton Hills has no normal of its own, so its county's is the closest measured readfrom Yuma County
- Soil character — no town-scale survey exists, so Wellton Hills's 409 acres read through its county's SSURGO summaryfrom Yuma County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Yuma 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 Yuma County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Wellton Hills's 409 acreswhy one lot differs from the next →
- Which side of Wellton 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 409 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 2.2 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 Wellton Hills-wide figureread your own land →
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