Coconino County, in Arizona, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Crops well matched to these conditions include cabbage, blackberry, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Coconino County lies within the Flagstaff & San Francisco Peaks High Country — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Coconino County holds more than one microclimate.
Soils and elevations shift across Coconino County, so your frost dates and drainage aren't the county average. 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 Coconino County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Coconino County — the short answer
Coconino County, Arizona: USDA zone 6a, about 150 days between hard freezes, across 11.9M acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 15
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 12
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~150
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 11.9M acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 6a is Coconino County's average, not your lot's — a low corner or a tree line moves it. Against Coconino County's 150-day season, see what your own ground reads.
Heat in Coconino County
Across a year, Coconino County accumulates about 1,941 growing degree days above 50°F, about 2,818 fewer than the middle Arizona county — no other Arizona county banks fewer. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Coconino County
Across Coconino County, the ground is predominantly Aridisols, where Winona, Sheppard, and Mespun are the most extensive named soil series. The soil is generally well drained with a fine sand surface. Topsoil pH runs about 7.6–8.2, slightly alkaline. Rainfall drains through hydrologic group D soils.
Soil order
Aridisols
Drainage
Well drained
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Coconino County
The USDA soil survey maps 63% of Coconino County as well drained — but another 23% drains differently: 12% excessively drained, 10% somewhat excessively drained.
Winona is the most extensive named soil at 9% of mapped acres, then Sheppard (5%) and Mespun (3%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Coconino County
Each reading below is measured for Coconino County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Coconino County are well drained, in hydrologic group D — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Coconino County runs about pH 7.6–8.2, on the alkaline side.
Many vegetables cope, but acid-lovers like blueberries struggle, and iron and manganese lock up above about pH 7.5 — leaves yellow between the veins even in rich soil.
Elemental sulfur and generous organic matter lower pH slowly for the beds that need it; test first so you add only what the soil actually calls for.
USDA NRCS SSURGO
Season length
MeasuredCoconino County runs about 150 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredCoconino County sits in USDA hardiness zone 6a.
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 Coconino County is in
Coconino County spans 3 EPA Level III ecoregions — Arizona/New Mexico Plateau (59%), Arizona/New Mexico Mountains (33%) and Colorado Plateaus (8%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Coconino County
We scored all 1,086 plants against Coconino County's own USDA zone 6a and its own 150-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Arizona profile.
Is it too late to plant in Coconino County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 17; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 15 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 12 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
Documented around Coconino County
- monarch butterfly86 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Coconino County
USGS estimates 1,513 lb of Glyphosate on Coconino County farmland in 2019, its largest by weight, ahead of Imidacloprid (124 lb) and Dinotefuran (83 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Coconino County — and how to grow with it.
We checked the federal record across Coconino County — 1,289 documented sites across 7 of the 9 source types we track.
The most significant on record: 11 Superfund sites (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Coconino County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Coconino County
Closest first, across Coconino County. Listing isn't leaking, and distance isn't exposure.
- DESERT VIEW SERVICE STATIONUnderground Storage Tanks · 14.8 mi
- 03 098-13.82X15.90Nitrate · 16.1 mi
- GrandviewMining · 17.2 mi
- Grandview MineMining · 17.2 mi
- 03 098-11.95X10.89Nitrate · 17.4 mi
- GALAWAY PROPERTYUnderground Storage Tanks · 17.8 mi
- THRIFTWAY #281Underground Storage Tanks · 17.8 mi
- A-27-09 06ADBNitrate · 17.9 mi
- A-27-09 06DCA1Nitrate · 17.9 mi
- ADOT - GRAY MOUNTAIN MAINTENANCE YARDUnderground Storage Tanks · 17.9 mi
- WAUNETA TRADING POSTUnderground Storage Tanks · 18.0 mi
- 03 098-11.17X10.05Nitrate · 18.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Coconino County'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 Coconino County.
Total Sites
1,289
across Coconino County
Risk Level
Elevated
Highest-severity
11 Superfund sites (none NPL-listed)
Sources Checked
across Coconino County
Severity Distribution
across Coconino County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Coconino County, Nitrate runs higher than the national average — 650 sites across Coconino County. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Coconino County
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 Coconino County average
Your land is one point inside Coconino County
Everything above resolves to Coconino County as a whole — one PHZM band and one county frost record, read across 11.9M 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 county 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 county average.
Your Lot vs the Coconino County Average
Coconino County Average
- ●USDA Zones 6a, averaged across Coconino County
- ●One soil character for all of Coconino County
- ●Frost dates read at Coconino County's scale: May 15 to Oct 12
YOUR Parcel
- ✓Your exact zone, not Coconino County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Coconino County
Pull a site-specific report for your exact address in Coconino County, Arizona — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Coconino County averages can't show:
We read public map data around Coconino County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Coconino County average
How we know this about Coconino County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Coconino County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Coconino County
When does frost risk typically end in Coconino County?
The last hard freeze (28°F) in Coconino County typically lands around May 15, 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 Jun 5.
How long is the growing season in Coconino County?
Measured between 28°F hard freezes, Coconino County sees about 150 frost-free days — roughly May 15 through Oct 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 5 to Sep 28, about 115 days.
Is the soil safe to grow vegetables in Coconino County?
The federal record around Coconino County is a meaningful one — 1,289 documented sites, mostly Nitrate entries (650), the nearest Underground Storage Tanks record about 15 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.
Everything above is measured at Coconino County's scale — its 6a band and its 150-day season. Your yard writes its own version of Coconino County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Arizona's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Coconino County’s own scale
9 of the readings below were taken at Coconino County's own scale — its own ~150-day span between 28°F freezes, the 3 most extensive soil series mapped here and 1,289 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Coconino County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Coconino County's own 28°F hard-freeze dates and its ~150-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Coconino CountyUSDA NRCS SSURGO
- 1,289 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 15 miles outFederal environmental registers
- Coconino County's boundary and the 11,914,463 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~150-day seasonGrowable Ground crop-matching engine
- The 3 ecoregions Coconino County spans, Arizona/New Mexico Plateau the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Coconino County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Coconino County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Arizona grower plans around — written at state scale, so they stay on the state guidefrom Arizona
What this page can’t tell you
- How the season shifts across Coconino County — the ~150 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Coconino County's 11,914,463 acreswhy one lot differs from the next →
- Which of those 1,289 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Coconino Countyread your own land →