Star Valley, Arizona, sits in USDA hardiness zone 8a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
The conditions favor cabbage, fig, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Star Valley, 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 Star Valley 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 Star Valley — soil, climate, flood, and parcel records. How we handle your address.
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Star Valley — the short answer
Star Valley, Arizona: USDA zone 8a, about 237 days between hard freezes, across 23K acres of town.
- USDA zone
- 8a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 24
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~237
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 23K 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 Star Valley's average, not your lot's — a low corner or a tree line moves it. Against Star Valley's 237-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Star Valley
Each reading below is measured for Star Valley itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredStar Valley runs about 237 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
MeasuredStar Valley 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 Star Valley is in
Star Valley sits in the Arizona/New Mexico Mountains — EPA Level III, inside the wider Temperate Sierras. That is read at Star Valley's own centroid rather than borrowed from Gila County.
What Grows in Star Valley
Every plant below cleared Star Valley's own zone 8a and its 237-day season. Each card opens that plant's Arizona profile. How we score.
Is it too late to plant in Star Valley?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 24 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 16 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Star Valley
Survey cells within 31 miles of Star Valley checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 351 miles off. What to watch for.
What's on the federal record near Star Valley
Closest first, within ~10 miles of Star Valley. Listing isn't leaking, and distance isn't exposure.
- A-11-11 27BCB1Nitrate · 1.1 mi
- A-11-11 29DADNitrate · 1.3 mi
- STAR AUTOMOTIVE INCUnderground Storage Tanks · 1.9 mi
- A-11-11 31ADC1Nitrate · 2.2 mi
- CIRCLE K #1442Underground Storage Tanks · 2.3 mi
- CIRCLE K #2706670Underground Storage Tanks · 2.4 mi
- GILA COUNTY - PAYSON HIGHWAY MAINTENANCEUnderground Storage Tanks · 3.2 mi
- PEMEX LTDUnderground Storage Tanks · 4.2 mi
- A-10H12 19DADNitrate · 4.3 mi
- A-11-11H20CBCNitrate · 4.3 mi
- A-11-10 23AAD3Nitrate · 4.6 mi
- A-11-10 23ADCNitrate · 4.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Star Valley'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 Star Valley.
Total Sites
204
within ~10 miles of Star Valley
Risk Level
Elevated
Highest-severity
4 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Star Valley
Severity Distribution
within ~10 miles of Star Valley
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Star Valley, two things run higher than the national average within ~10 miles of Star Valley — Nitrate (118 sites) and Mining (24 sites). That's not a problem with your land — it's information about it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
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 well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Star Valley
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 Star Valley average
Your land is one point inside Star Valley
Everything above resolves to Star Valley as a whole — one PHZM band and one 28°F frost record, read across 23K 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 Star Valley Average
Star Valley Average
- ●USDA Zones 8a, averaged across Star Valley
- ●One soil character for all of Star Valley
- ●Frost dates read at Star Valley's scale: Mar 24 to Nov 16
YOUR Parcel
- ✓Your exact zone, not Star Valley's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Star Valley
Pull a site-specific report for your exact address in Star Valley, Arizona — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Star Valley averages can't show:
We read public map data around Star Valley — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Star Valley average
How we know this about Star Valley
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 Star Valley’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 Star Valley
When does frost risk typically end in Star Valley?
The last hard freeze (28°F) in Star Valley typically lands around Mar 24, 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 14.
When is the first frost in Star Valley?
The first hard freeze (28°F) in Star Valley typically arrives around Nov 16, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 2, so the watching starts about Oct 17 — about 237 days after the spring freeze cleared.
How long is the growing season in Star Valley?
Measured between 28°F hard freezes, Star Valley sees about 237 frost-free days — roughly Mar 24 through Nov 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 14 to Nov 2, about 202 days.
Is the soil safe to grow vegetables in Star Valley?
The federal record around Star Valley is a meaningful one — 204 documented sites, mostly Nitrate entries (118), the nearest Nitrate record about 1.1 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 Star Valley?
From about Oct 17 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 16 (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 16. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Star Valley's scale — its 8a band and its 237-day season. Your yard writes its own version of Star Valley'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 Star Valley’s own scale
7 of the readings below were taken at Star Valley's own scale — its own ~237-day season between 28°F freezes, the 23,132 acres it covers and 204 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Star Valley's own USDA hardiness band, zones 8aUSDA PHZM 2023
- Star Valley's own 28°F hard-freeze dates, about Mar 24 and Nov 16 and the ~237-day span between themNOAA 1991–2020 Climate Normals
- 204 documented contamination sites on the federal record near Star Valley, the closest Nitrate record about 1.1 miles out from the town centreFederal environmental registers
- Star Valley's boundary and the 23,132 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~237-day seasonGrowable Ground crop-matching engine
- The ecoregion at Star Valley's own centroid, the Arizona/New Mexico MountainsUS EPA Level III Ecoregions
- Lanternfly survey cells around Star Valley 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 Star Valley's 23,132 acres read through its county's SSURGO summaryfrom Gila County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Gila 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 Gila County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Star Valley's 23,132 acreswhy one lot differs from the next →
- Which side of Star Valley you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 23,132 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 1.1 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 Star Valley-wide figureread your own land →