Arizona spans USDA hardiness zones 5b-10b, with a growing season of about 266 frost-free days — close to year-round growing, where winter plantings are as real as summer ones and heat tolerance matters more than frost.
What the season actually delivers comes down to 3-25 inches of annual rainfall, a median of roughly 3,945 growing-degree days (base 50°F), and about 2,087 winter chill hours for tree fruit. The prevailing soils — caliche, sandy loam, desert pavement, and alluvial — differ most in how they drain, which is exactly where crop success is usually decided. What grows in Arizona depends on where in it you stand — Sonoran Desert, Sonoita / Elgin, and Lower Colorado River Corridor each run on their own zones and frost timing. Growers here do well with palo verde, citrus, jalapeno, and date palm — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Grounded inUSDA PHZM•NOAA Climate Normals•USDA NRCS SSURGO•GDD (PRISM 1991-2020 normals)•Chill hours (PRISM 1991-2020 normals)•USDA hardiness sub-region map•EPA FRS•USDA PLANTS•Growable Ground suitability scoring
Arizona spans zones 5b-10b, but your yard sits in exactly one — and slope, tree cover, and low spots nudge it further. 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 Arizona — soil, climate, flood, and parcel records. How we handle your address.
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Distinct growing regions within Arizona — each has its own zones, soils, and signature crops.
Arizona: USDA zones 5b-10b, 150–345 frost-free days depending on the county, 15 counties.
The middle half of this state’s counties. Tender transplants usually wait 2–3 weeks past the last hard freeze. The shortest-season figure is Arizona's own county record — Coconino County's measured 28°F normal, not a modeled floor.
Zone 5b-10b is Arizona's average, not your lot's — a low corner or a tree line moves it. Against Arizona's 266-day season, see what your own ground reads.
One answer for Arizona averages 15 counties whose growing seasons are 195 days apart — from 150 frost-free days in Coconino County to 345 in Maricopa County. That is the same state, measured the same way, in the same years. Which end of it your county sits nearer decides what finishes before the first hard freeze.
The middle half of 15 counties runs 207–316 days, with a median of 266 days — a 195-day span end to end.
Measured across 15 counties, each carrying its own 28°F normal. NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze. A county with no record of its own is absent from the range rather than counted as zero — nothing here is interpolated to the state. Your own site sits somewhere inside this range; a parcel report resolves where.
The middle half of Arizona runs 207–316 frost-free days, and 6 of its 15 counties sit outside that — 3 on the short side, 3 on the long. A statewide planting date describes the middle well and the ends poorly, which is worth knowing before you follow one.
Under 207 frost-free days
3 counties
The end of the state that sets the planting calendar — start seed indoors here and the season stretches to meet the crop.
207–316 frost-free days
9 counties
0 of 9 shown
The middle half of the state, and the part a single statewide date describes well.
Over 316 frost-free days
3 counties
Long enough for a second succession of a quick crop after the first comes out.
Each county is placed by its own 28°F frost-free normal (NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze), the same figure its own guide page publishes. Elevation, slope and cold-air drainage move a yard within its county as well — which is the part only your address resolves.
The soil types that dominate Arizona — how each drains decides more about crop success than almost anything else. Tap any soil to learn what it is and how to work with it. Each photo is a representative profile of that soil type; the named series is where it was documented, which is often another state.
Drainage
The layer itself is nearly waterproof: water perches on top of it, and roots stop where it starts unless it is broken.
What thrives
Desert natives handle caliche country naturally — mesquite, desert willow, agave, and wildflowers. Vegetables and fruit trees succeed where planting holes punch through the layer or beds rise above it.
Drainage
Fast. The sand fraction opens the soil up, so water moves through the root zone quickly and the surface rarely stays soggy. The trade is that nutrients ride out with the water.
What thrives
Root crops love it — carrots, potatoes, radishes, and onions size up cleanly in ground they can push through. Melons, sweet potatoes, asparagus, and most herbs appreciate the warmth and the drainage.
Drainage
The pavement sheds most rain across its surface; what soaks through meets fine, often lime-rich material beneath.
What thrives
The desert’s own — creosote, ocotillo, cactus, and the wildflower seed bank that erupts after wet winters. Food growing happens in built beds, not in the pavement.
Drainage
Usually good: rivers sort their loads, and most alluvial soils have enough sand and silt to move water while holding plenty for roots. Low-lying pockets can run wet.
What thrives
Nearly everything — vegetables, orchards, vines, and berries all prosper on alluvium. Its depth lets roots go as far down as they care to.
Soil data: USDA NRCS SSURGO · Soil types explained
Plants well-suited to Arizona's climate, soils, and growing season — each links to its full growing profile.
Usually not — gardeners here simply switch what goes in the ground as the season moves. Across Arizona, cool-season planting typically opens about four weeks before the local last hard freeze — county medians put that freeze near Feb 26, with the middle half of counties between Feb 1 and Apr 2 (NOAA 1991–2020 climate normals). Tender transplants wait two to three weeks past it, and fall planting counts back from first freezes mostly between Nov 13 and Dec 12 — 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.
The plants Arizona put its name on — cultural emblems, not growing recommendations.
Saguaro cactus blossom
Carnegiea gigantea
Designated 1931.
Parkinsonia florida
Designated 1954. In our plant library — see its full growing profile.
Plants the USDA PLANTS Database documents as native and present in Arizona — a real per-state range, not just a zone match. Ordered by how closely each plant’s published hardiness range matches Arizona’s zones 5b-10b, so this is a shortlist by climate fit, not a ranking of which plants matter most here. Presence is statewide, so a plant may still be uncommon in your specific county; your state’s Cooperative Extension or a native-plant society is the local authority.
US-native plants whose hardiness range overlaps Arizona’s USDA zones 5b-10b but which USDA PLANTS doesn’t map to a single state range here. Zone overlap is a starting filter, not a range map.
What an experienced grower plans around here — each one has a move.
Extreme heat exceeding 110F stresses most plants
Desert gardens run on winter: plant to the October-March windows and give the summer holdouts afternoon shade.
Minimal rainfall requires drip irrigation
Drip plus a deep mulch layer is the desert baseline — it waters roots, not air, and cuts evaporation dramatically.
Caliche hardpan prevents root penetration without breaking through
Where caliche won't break, build up instead — a deep raised bed gives roots the depth the ground refuses.
For cultivar selection, pest pressure, and planting-time guidance specific to Arizona, the University of Arizona Cooperative Extension is the authoritative local source.
Safe to Grow Here?What the federal record shows across Arizona — and how to grow with it.
We checked the federal record across Arizona — 32,297 documented sites across 7 of the 9 source types we track.
The most significant on record: 184 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Arizona carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Severity Distribution
across Arizona
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Arizona, two things run higher than the national average across Arizona — Mining (6,160 sites) and Nitrate (11,388 sites). 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.
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).
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
Everything above resolves to Arizona as a whole — a state whose own counties record seasons 195 days apart, and hardiness across zones 5b-10b. Your parcel sits at one point in that range, not in the middle of it. 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 state 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 statewide average.
State averages sketch the shape. Your soil, sun exposure, drainage, and microclimate decide what actually takes. Pull a site-specific report for your exact parcel.
Enter your address. We read your soil, sun, drainage, and frost dates, then score 1,086 plants against the real conditions on your land.
Three things about your lot that Arizona averages can't show:
We read public map data around Arizona — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Arizona average
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read per county and aggregated to the state band; the growing season from NOAA Regional Climate Centers ACIS 1991–2020 28°F normals, read at each county’s own record; rainfall from NOAA Climate Normals; soils from USDA NRCS SSURGO; boundaries from US Census TIGER/Line 2025; the contamination record from the federal sources named in that beat above. Where a county carries no record of its own, it is absent from the figure rather than filled in.
Arizona spans USDA hardiness zones 5b-10b — which is to say winter's coldest night runs from about −15°F to 40°F depending where in Arizona you are, averaged over 1991–2020 (USDA PHZM 2023).
Usually not — gardeners here simply switch what goes in the ground as the season moves. Across Arizona, cool-season planting typically opens about four weeks before the local last hard freeze — county medians put that freeze near Feb 26, with the middle half of counties between Feb 1 and Apr 2 (NOAA 1991–2020 climate normals). Tender transplants wait two to three weeks past it, and fall planting counts back from first freezes mostly between Nov 13 and Dec 12 — 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.
Across Arizona, the middle half of counties see their last hard freeze (28°F) between about Feb 1 and Apr 2, with a county median near Feb 26 (NOAA 1991–2020 climate normals). 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 Mar 19.
Measured between 28°F hard freezes, growing seasons across Arizona's counties mostly run about 225 to 315 days, with a county median near 266 (NOAA 1991–2020 climate normals). Tender crops get a somewhat shorter practical window, since lighter frosts reach a few weeks past the hard-freeze dates on both ends.
Arizona's zones 5b-10b support a wide range — strong performers include Palo Verde, Citrus, Jalapeno, Date Palm, and Prickly Pear. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Officially, Arizona spans USDA zones 5b-10b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,086 plants against what's actually there.
The federal record across Arizona runs heavier than most — 32,297 documented sites, mostly Nitrate entries (11,388) — 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.
Start with three facts. Arizona spans USDA zones 5b-10b, which sets what survives winter; last hard freezes range from about Feb 1 to Apr 2 across its counties (NOAA 1991–2020 climate normals); and 32,297 documented sites sit on the federal record here, so a soil test before food beds is the smart first step. From there, matching plants to your actual soil and sun is the fun part.
Everything above is measured at Arizona's scale — its 5b-10b band and its 266-day season. Your yard writes its own version of Arizona's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
6 of the readings below were taken at Arizona's own scale — the full zone 5b-10b span inside its borders, the 4 soil types that dominate its ground and 32,297 documented sites on its federal record; anything it cannot resolve at this scale is named below.
Measured here
What this page can’t tell you
Explore growing conditions by city or town in Arizona.
Arizona shares its dominant growing region with these states — a useful comparison if you're weighing where a crop will behave the same way.
