Cortez, Colorado, sits in USDA hardiness zone 6a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Among the crops suited to this profile: cabbage, blackberry, california poppy, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Cortez, 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 Cortez 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 Cortez — soil, climate, flood, and parcel records. How we handle your address.
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Cortez — the short answer
Cortez, Colorado: USDA zone 6a, about 166 days between hard freezes, across 4K acres of city.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 2
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 15
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~166
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 4K 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 6a is Cortez's average, not your lot's — a low corner or a tree line moves it. Against Cortez's 166-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Cortez
Each reading below is measured for Cortez itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredCortez runs about 166 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
MeasuredCortez 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 Cortez is in
Cortez sits in the Colorado Plateaus — EPA Level III, inside the wider North American Deserts. That is read at Cortez's own centroid rather than borrowed from Montezuma County.
What Grows in Cortez
Every plant below cleared Cortez's own zone 6a and its 166-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Cortez?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Apr 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 2 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 15 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What's on the federal record near Cortez
Closest first, within ~10 miles of Cortez. Listing isn't leaking, and distance isn't exposure.
- Auto DiscountUnderground Storage Tanks · 400 ft
- DILLON COMPANIES DBA CITY MARKET INCBrownfields · 500 ft
- Four Corners Kar MartUnderground Storage Tanks · 600 ft
- Main Street SinclairUnderground Storage Tanks · 600 ft
- City Market #208Underground Storage Tanks · 650 ft
- Sonoco Car WashUnderground Storage Tanks · 1000 ft
- Giant #7260Underground Storage Tanks · 1200 ft
- Circle K #0773Underground Storage Tanks · 1200 ft
- 7-2-11 Food Store #11Underground Storage Tanks · 1300 ft
- Jiffy StopUnderground Storage Tanks · 1300 ft
- Colorado Denver WarehouseUnderground Storage Tanks · 1400 ft
- SOUTHWEST HEALTH SYSTEMBrownfields · 1400 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Cortez'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 Cortez.
Total Sites
116
within ~10 miles of Cortez
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Cortez
Severity Distribution
within ~10 miles of Cortez
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Cortez, Underground Storage Tanks runs higher than the national average — 93 sites within ~10 miles of Cortez. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Cortez
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 Cortez average
Your land is one point inside Cortez
Everything above resolves to Cortez as a whole — one PHZM band and one 28°F frost record, read across 4K 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 city 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 Cortez Average
Cortez Average
- ●USDA Zones 6a, averaged across Cortez
- ●One soil character for all of Cortez
- ●Frost dates read at Cortez's scale: May 2 to Oct 15
YOUR Parcel
- ✓Your exact zone, not Cortez's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Cortez
Pull a site-specific report for your exact address in Cortez, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Cortez averages can't show:
We read public map data around Cortez — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Cortez average
How we know this about Cortez
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Cortez’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 city grain anywhere on this page — there is no city-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 Cortez
When does frost risk typically end in Cortez?
The last hard freeze (28°F) in Cortez typically lands around May 2, 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 May 23.
When is the first frost in Cortez?
The first hard freeze (28°F) in Cortez typically arrives around Oct 15, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 1, so the watching starts about Sep 15 — about 166 days after the spring freeze cleared.
How long is the growing season in Cortez?
Measured between 28°F hard freezes, Cortez sees about 166 frost-free days — roughly May 2 through Oct 15, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 23 to Oct 1, about 131 days.
Is the soil safe to grow vegetables in Cortez?
The federal record around Cortez is a meaningful one — 116 documented sites, mostly Underground Storage Tanks entries (93), the nearest Underground Storage Tanks record under a tenth of a mile 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 Cortez?
From about Sep 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 Oct 15 (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 Oct 15. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Cortez's scale — its 6a band and its 166-day season. Your yard writes its own version of Cortez'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 Cortez’s own scale
6 of the readings below were taken at Cortez's own scale — its own ~166-day season between 28°F freezes, the 3,987 acres it covers and 116 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Cortez's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Cortez's own 28°F hard-freeze dates, about May 2 and Oct 15 and the ~166-day span between themNOAA 1991–2020 Climate Normals
- 116 documented contamination sites on the federal record near Cortez, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Cortez's boundary and the 3,987 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~166-day seasonGrowable Ground crop-matching engine
- The ecoregion at Cortez's own centroid, the Colorado PlateausUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Cortez's 3,987 acres read through its county's SSURGO summaryfrom Montezuma County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Montezuma County
- The growing challenges every Colorado grower plans around — written at state scale, so they stay on the state guidefrom Colorado
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Montezuma County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Cortez's 3,987 acreswhy one lot differs from the next →
- Which side of Cortez you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,987 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 Cortez-wide figureread your own land →
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