La Paz Valley, Arizona, sits in USDA hardiness zone 9a — a zone band wide enough that plant choice, not possibility, is the interesting question.
These conditions suit jalapeno, palo verde, date palm, and prickly pear — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in La Paz 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 La Paz 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 La Paz Valley — soil, climate, flood, and parcel records. How we handle your address.
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La Paz Valley — the short answer
La Paz Valley, Arizona: USDA zone 9a, about 345 days between hard freezes, across 19K acres of town.
- USDA zone
- 9a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 18
- La Paz County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 29
- La Paz County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~345
- La Paz County normal — NOAA 1991–2020, nearest to this town
- Town area
- 19K 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 La Paz County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9a is La Paz Valley's average, not your lot's — a low corner or a tree line moves it. Against La Paz Valley's 345-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in La Paz Valley
Each reading below is measured for La Paz Valley itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsLa Paz Valley runs about 345 days between hard freezes (read from La Paz County, the closest normal to La Paz Valley) — 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
MeasuredLa Paz Valley 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 La Paz Valley is in
La Paz Valley sits in the Sonoran Basin and Range — EPA Level III, inside the wider North American Deserts. That is read at La Paz Valley's own centroid rather than borrowed from La Paz County.
What Grows in La Paz Valley
Plants matched to La Paz Valley's USDA zones 9a, ordered by how much hardiness margin each has here — the ones with room to spare at both ends of this town's band lead. Each links to its full growing profile.
Is it too late to plant in La Paz Valley?
Rarely: the season closes in stages, not all at once, and each stage has its crops. 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 18 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 29 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.
What's on the federal record near La Paz Valley
Closest first, within ~10 miles of La Paz Valley. Listing isn't leaking, and distance isn't exposure.
- B-03-19 29BCDNitrate · 1.1 mi
- Yum Yum MineMining · 3.8 mi
- Green GloryMining · 4.5 mi
- Cinnabar MineMining · 4.7 mi
- La Chacha and Scott-WeaverMining · 5.1 mi
- Copper Bottom MineMining · 5.4 mi
- Bee HiveMining · 5.4 mi
- StibniteMining · 5.4 mi
- Copper BottomMining · 5.4 mi
- French-American ProspectMining · 5.5 mi
- RainbowMining · 5.6 mi
- B-03-20 16DBANitrate · 5.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from La Paz 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 La Paz Valley.
Total Sites
92
within ~10 miles of La Paz Valley
Risk Level
High
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of La Paz Valley
Severity Distribution
within ~10 miles of La Paz Valley
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around La Paz Valley, two things run higher than the national average within ~10 miles of La Paz Valley — Mining (36 sites) and Nitrate (36 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around 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 La Paz 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 La Paz Valley average
Your land is one point inside La Paz Valley
Everything above resolves to La Paz Valley as a whole — one PHZM band, read across 19K acres, with hard-freeze dates borrowed from La Paz 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 La Paz Valley Average
La Paz Valley Average
- ●USDA Zones 9a, averaged across La Paz Valley
- ●One soil character for all of La Paz Valley
- ●Frost dates read at La Paz Valley's scale: Jan 18 to Dec 29
YOUR Parcel
- ✓Your exact zone, not La Paz Valley's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in La Paz Valley
Pull a site-specific report for your exact address in La Paz Valley, Arizona — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that La Paz Valley averages can't show:
We read public map data around La Paz Valley — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the La Paz Valley average
How we know this about La Paz 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 La Paz 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 La Paz Valley
When does frost risk typically end in La Paz Valley?
The last hard freeze (28°F) in La Paz Valley typically lands around Jan 18, 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 8.
When is the first frost in La Paz Valley?
The first hard freeze (28°F) in La Paz Valley typically arrives around Dec 29, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Dec 15, so the watching starts about Nov 29 — about 345 days after the spring freeze cleared.
How long is the growing season in La Paz Valley?
Measured between 28°F hard freezes, La Paz Valley sees about 345 frost-free days — roughly Jan 18 through Dec 29, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 8 to Dec 15, about 310 days.
Is the soil safe to grow vegetables in La Paz Valley?
The federal record around La Paz Valley runs heavier than most — 92 documented sites, mostly Mining entries (36), the nearest Nitrate record about 1.1 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 La Paz Valley?
From about Nov 29 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 29 (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 29. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at La Paz Valley's scale — its 9a band and its 345-day season. Your yard writes its own version of La Paz 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 La Paz Valley’s own scale
4 of the readings below were taken at La Paz Valley's own scale — the 18,794 acres it covers and 92 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- La Paz Valley's own USDA hardiness band, zones 9aUSDA PHZM 2023
- 92 documented contamination sites on the federal record near La Paz Valley, the closest Nitrate record about 1.1 miles out from the town centreFederal environmental registers
- La Paz Valley's boundary and the 18,794 acres inside itUS Census TIGER/Line 2025
- The ecoregion at La Paz Valley's own centroid, the Sonoran Basin and RangeUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — La Paz Valley has no normal of its own, so its county's is the closest measured readfrom La Paz County
- Soil character — no town-scale survey exists, so La Paz Valley's 18,794 acres read through its county's SSURGO summaryfrom La Paz County
- The candidate plant list — Arizona's curated set, filtered to this zone band and re-ordered by how much margin each has herefrom Arizona
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom La Paz 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 La Paz County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among La Paz Valley's 18,794 acreswhy one lot differs from the next →
- Which side of La Paz 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 18,794 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 La Paz Valley-wide figureread your own land →
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