Round Valley, Arizona, sits in USDA hardiness zone 8a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Among the crops suited to this profile: cabbage, fig, california poppy, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Round 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 Round 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 Round Valley — soil, climate, flood, and parcel records. How we handle your address.
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Round Valley — the short answer
Round Valley, Arizona: USDA zone 8a, about 232 days between hard freezes, across 3K acres of town.
- USDA zone
- 8a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 14
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~232
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 3K 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 Round Valley's average, not your lot's — a low corner or a tree line moves it. Against Round Valley's 232-day season, see what your own ground reads.
Your town runs its own season
Round Valley's own 30-year record measures about 232 days between 28°F killing freezes — 63 days shorter than Gila County's ~295. Both are measured records, not estimates.
That gap is the whole reason a county average can mislead here. Plant against Round Valley's ~232-day season rather than the county figure — and the sun, slope and cold-air drainage on your specific lot move it again.
NOAA Regional Climate Centers ACIS (1991–2020), 30-year daily minimum record. Both figures are measured records — this town’s own and its county’s. A town with no record of its own is absent here rather than estimated.
Soil varies lot by lot — soil types explained.
What this means for growing in Round Valley
Each reading below is measured for Round Valley itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredRound Valley runs about 232 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
MeasuredRound 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 Round Valley is in
Round Valley sits in the Arizona/New Mexico Mountains — EPA Level III, inside the wider Temperate Sierras. That is read at Round Valley's own centroid rather than borrowed from Gila County.
What Grows in Round Valley
Every plant below cleared Round Valley's own zone 8a and its 232-day season. Each card opens that plant's Arizona profile. How we score.
Is it too late to plant in Round Valley?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Feb 27; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 14 — 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.
Documented around Round Valley
Survey cells within 31 miles of Round Valley checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 345 miles off. What to watch for.
What's on the federal record near Round Valley
Closest first, within ~10 miles of Round Valley. Listing isn't leaking, and distance isn't exposure.
- No Dice Number 1 ClaimMining · 0.7 mi
- A-10-10 22DBD1Nitrate · 0.8 mi
- SHUMWAY MILLSITESSuperfund · 1.7 mi
- Bishop's Knoll MineMining · 1.8 mi
- Mineral Survey 4636Mining · 2.0 mi
- LANNY FLOYD TRUCKING INCUnderground Storage Tanks · 2.2 mi
- A-10-10 28BCA2Nitrate · 2.2 mi
- Bishop Knoll PropertyMining · 2.3 mi
- A-10-10 29ACA2Nitrate · 2.7 mi
- Bratlin PropertyMining · 2.7 mi
- LDS PAYSON 1,2 CAMP VERDE STAKEUnderground Storage Tanks · 3.0 mi
- DAKOTA LEEUnderground Storage Tanks · 3.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Round 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 Round Valley.
Total Sites
218
within ~10 miles of Round Valley
Risk Level
Elevated
Highest-severity
4 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Round Valley
Severity Distribution
within ~10 miles of Round Valley
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Round Valley, two things run higher than the national average within ~10 miles of Round Valley — Mining (47 sites) and Nitrate (108 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 Round 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 Round Valley average
Your land is one point inside Round Valley
Everything above resolves to Round Valley as a whole — and this is a town whose own 30-year record already runs a season its county’s does not. Your parcel sits at one point inside even that. 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 Round Valley Average
Round Valley Average
- ●USDA Zones 8a, averaged across Round Valley
- ●One soil character for all of Round Valley
- ●Frost dates read at Round Valley's scale: Mar 27 to Nov 14
YOUR Parcel
- ✓Your exact zone, not Round Valley's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Round Valley
Pull a site-specific report for your exact address in Round Valley, Arizona — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Round Valley averages can't show:
We read public map data around Round Valley — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Round Valley average
How we know this about Round 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 Round 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 Round Valley
When does frost risk typically end in Round Valley?
The last hard freeze (28°F) in Round Valley typically lands around Mar 27, 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 17.
When is the first frost in Round Valley?
The first hard freeze (28°F) in Round Valley typically arrives around Nov 14, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 31, so the watching starts about Oct 15 — about 232 days after the spring freeze cleared.
How long is the growing season in Round Valley?
Measured between 28°F hard freezes, Round Valley sees about 232 frost-free days — roughly Mar 27 through Nov 14, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 17 to Oct 31, about 197 days.
Is the soil safe to grow vegetables in Round Valley?
The federal record around Round Valley is a meaningful one — 218 documented sites, mostly Nitrate entries (108), the nearest Mining record about 0.7 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 Round Valley?
From about Oct 15 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 14 (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 14. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Round Valley's scale — its 8a band and its 232-day season. Your yard writes its own version of Round 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 Round Valley’s own scale
7 of the readings below were taken at Round Valley's own scale — its own ~232-day season between 28°F freezes, the 3,063 acres it covers and 218 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Round Valley's own USDA hardiness band, zones 8aUSDA PHZM 2023
- Round Valley's own 28°F hard-freeze dates, about Mar 27 and Nov 14 and the ~232-day span between themNOAA 1991–2020 Climate Normals
- 218 documented contamination sites on the federal record near Round Valley, the closest Mining record about 0.7 miles out from the town centreFederal environmental registers
- Round Valley's boundary and the 3,063 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~232-day seasonGrowable Ground crop-matching engine
- The ecoregion at Round Valley's own centroid, the Arizona/New Mexico MountainsUS EPA Level III Ecoregions
- Lanternfly survey cells around Round 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 Round Valley's 3,063 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 Round Valley's 3,063 acreswhy one lot differs from the next →
- Which side of Round 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 3,063 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Mining record about 0.7 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 Round Valley-wide figureread your own land →
More in Arizona
Wider growing context
What grows across ArizonaRound Valley sits outside our named growing regions, so Arizona as a whole is its closest context here.
Nearby growing guides