So-Hi, Arizona, sits in USDA hardiness zone 8b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Reliable performers under these conditions include cabbage, fig, california poppy, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in So-Hi, 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 So-Hi 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 So-Hi — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
So-Hi — the short answer
So-Hi, Arizona: USDA zone 8b, about 242 days between hard freezes, across 561 acres of town.
- USDA zone
- 8b
- 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
- 561 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 8b is So-Hi's average, not your lot's — a low corner or a tree line moves it. Against So-Hi's 242-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in So-Hi
Each reading below is measured for So-Hi itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsSo-Hi runs about 242 days between hard freezes (read from Mohave County, the closest normal to So-Hi) — 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
MeasuredSo-Hi sits in USDA hardiness zone 8b.
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 So-Hi is in
So-Hi sits in the Mojave Basin and Range — EPA Level III, inside the wider North American Deserts. That is read at So-Hi's own centroid rather than borrowed from Mohave County.
What Grows in So-Hi
Every plant below cleared So-Hi's own zone 8b and its 242-day season. Each card opens that plant's Arizona profile. How we score.
Is it too late to plant in So-Hi?
Almost never — the real question is what to plant next. 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. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around So-Hi
Survey cells within 31 miles of So-Hi checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 226 miles off. What to watch for.
What's on the federal record near So-Hi
Closest first, within ~10 miles of So-Hi. Listing isn't leaking, and distance isn't exposure.
- B-22-17 31ABB1Nitrate · 0.6 mi
- GOLDEN SAGE RANCHOSUnderground Storage Tanks · 0.8 mi
- CASTLE ROCK BARUnderground Storage Tanks · 1.3 mi
- PARCEL 305-06-065AUnderground Storage Tanks · 1.7 mi
- White Elephant MineMining · 2.2 mi
- DiplomatMining · 2.3 mi
- THE OUTPOSTUnderground Storage Tanks · 2.4 mi
- New LondonMining · 2.5 mi
- New London MineMining · 2.5 mi
- IWX MOTOR FREIGHTUnderground Storage Tanks · 2.6 mi
- DOMINQUEZ MARKETUnderground Storage Tanks · 2.7 mi
- ADOT - PORT OF ENTRYUnderground Storage Tanks · 2.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from So-Hi'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 So-Hi.
Total Sites
468
within ~10 miles of So-Hi
Risk Level
High
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of So-Hi
Severity Distribution
within ~10 miles of So-Hi
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around So-Hi, Mining runs higher than the national average — 213 sites within ~10 miles of So-Hi. 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 So-Hi
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 So-Hi average
Your land is one point inside So-Hi
Everything above resolves to So-Hi as a whole — one PHZM band, read across 561 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 So-Hi Average
So-Hi Average
- ●USDA Zones 8b, averaged across So-Hi
- ●One soil character for all of So-Hi
- ●Frost dates read at So-Hi's scale: Mar 21 to Nov 18
YOUR Parcel
- ✓Your exact zone, not So-Hi's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in So-Hi
Pull a site-specific report for your exact address in So-Hi, Arizona — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that So-Hi averages can't show:
We read public map data around So-Hi — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the So-Hi average
How we know this about So-Hi
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 So-Hi
When does frost risk typically end in So-Hi?
The last hard freeze (28°F) in So-Hi 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 So-Hi?
The first hard freeze (28°F) in So-Hi 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 So-Hi?
Measured between 28°F hard freezes, So-Hi 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 So-Hi?
The federal record around So-Hi runs heavier than most — 468 documented sites, mostly Mining entries (213), the nearest Nitrate record about 0.6 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 So-Hi?
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 So-Hi's scale — its 8b band and its 242-day season. Your yard writes its own version of So-Hi'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 So-Hi’s own scale
6 of the readings below were taken at So-Hi's own scale — the 561 acres it covers and 468 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- So-Hi's own USDA hardiness band, zones 8bUSDA PHZM 2023
- 468 documented contamination sites on the federal record near So-Hi, the closest Nitrate record about 0.6 miles out from the town centreFederal environmental registers
- So-Hi's boundary and the 561 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8b and a ~242-day seasonGrowable Ground crop-matching engine
- The ecoregion at So-Hi's own centroid, the Mojave Basin and RangeUS EPA Level III Ecoregions
- Lanternfly survey cells around So-Hi checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- The 28°F hard-freeze dates — So-Hi 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 So-Hi's 561 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 So-Hi's 561 acreswhy one lot differs from the next →
- Which side of So-Hi you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 561 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.6 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 So-Hi-wide figureread your own land →
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