Montezuma County, in Colorado, sits in USDA hardiness zone 6a — a zone band wide enough that plant choice, not possibility, is the interesting question.
A short list that earns its place here — cabbage, blackberry, california poppy, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Montezuma County lies within the Four Corners / Southwest Colorado — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Montezuma County holds more than one microclimate.
Soils and elevations shift across Montezuma 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 Montezuma County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Montezuma County — the short answer
Montezuma County, Colorado: USDA zone 6a, about 166 days between hard freezes, across 1.3M acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 2
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 15
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~166
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 1.3M 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 Montezuma County's average, not your lot's — a low corner or a tree line moves it. Against Montezuma County's 166-day season, see what your own ground reads.
Heat in Montezuma County
Across a year, Montezuma County accumulates about 2,364 growing degree days above 50°F, about 532 more than the middle Colorado county — ahead of 39 of Colorado’s 64 counties. 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 Montezuma County
Across Montezuma County, the ground is predominantly Alfisols, where Wetherill, Romberg, and Crosscan are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 6.9–7.8, neutral. Rainfall drains through hydrologic group D soils.
Soil order
Alfisols
Drainage
Well drained
Hydric soils
1%
Soil still varies lot by lot — soil types explained.
How the ground varies across Montezuma County
The USDA soil survey maps 94% of Montezuma County as well drained — but another 3% drains differently: 1% excessively drained, 1% somewhat excessively drained.
Wetherill is the most extensive named soil at 8% of mapped acres, then Romberg (5%) and Crosscan (4%).
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 Montezuma County
Each reading below is measured for Montezuma 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 Montezuma 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 Montezuma County runs about pH 6.9–7.8, 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
MeasuredMontezuma County 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
MeasuredMontezuma 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 Montezuma County is in
Montezuma County spans 2 EPA Level III ecoregions — Colorado Plateaus (79%) and Southern Rockies (21%). 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 Montezuma County
We scored all 1,086 plants against Montezuma County's own USDA zone 6a and its own 166-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 Colorado profile.
Is it too late to plant in Montezuma County?
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. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
Documented around Montezuma County
- monarch butterfly1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Montezuma County
USGS estimates 23,365 lb of Glyphosate on Montezuma County farmland in 2019, its largest by weight, ahead of Dicamba (5,570 lb) and Atrazine (5,392 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 Montezuma County — and how to grow with it.
We checked the federal record across Montezuma County — 207 documented sites across 7 of the 9 source types we track.
The most significant on record: 1 Superfund site (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 Montezuma 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 Montezuma County
Closest first, across Montezuma County. Listing isn't leaking, and distance isn't exposure.
- Quick & Easy GasUnderground Storage Tanks · 1000 ft
- Handy Mart SouthUnderground Storage Tanks · 1200 ft
- Mountain West ChevronUnderground Storage Tanks · 1400 ft
- Chief One StopUnderground Storage Tanks · 1400 ft
- Hintons Service CenterUnderground Storage Tanks · 1900 ft
- South Broadway KarwashUnderground Storage Tanks · 2000 ft
- SOUTHWEST AUTO CENTERBrownfields · 2200 ft
- Tsaya Trading CoUnderground Storage Tanks · 2400 ft
- E-z MartUnderground Storage Tanks · 2400 ft
- Chittie Betoe StoreUnderground Storage Tanks · 2400 ft
- FAMILY DOLLAR #11029Brownfields · 2500 ft
- Old Texaco Station 3rd & S BroadwayUnderground Storage Tanks · 0.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Montezuma 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 Montezuma County.
Total Sites
207
across Montezuma County
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
across Montezuma County
Severity Distribution
across Montezuma County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Montezuma County, Mining runs higher than the national average — 21 sites across Montezuma County. 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.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Montezuma 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 Montezuma County average
Your land is one point inside Montezuma County
Everything above resolves to Montezuma County as a whole — one PHZM band and one county frost record, read across 1.3M 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 Montezuma County Average
Montezuma County Average
- ●USDA Zones 6a, averaged across Montezuma County
- ●One soil character for all of Montezuma County
- ●Frost dates read at Montezuma County's scale: May 2 to Oct 15
YOUR Parcel
- ✓Your exact zone, not Montezuma County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Montezuma County
Pull a site-specific report for your exact address in Montezuma County, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Montezuma County averages can't show:
We read public map data around Montezuma County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Montezuma County average
How we know this about Montezuma 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 Montezuma County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Montezuma County
When does frost risk typically end in Montezuma County?
The last hard freeze (28°F) in Montezuma County 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.
How long is the growing season in Montezuma County?
Measured between 28°F hard freezes, Montezuma County 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 Montezuma County?
The federal record around Montezuma County is a meaningful one — 207 documented sites, mostly Underground Storage Tanks entries (114), the nearest Underground Storage Tanks record about 0.2 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 Montezuma County's scale — its 6a band and its 166-day season. Your yard writes its own version of Montezuma 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 Colorado's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Montezuma County’s own scale
9 of the readings below were taken at Montezuma County's own scale — its own ~166-day span between 28°F freezes, the 3 most extensive soil series mapped here and 207 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Montezuma County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Montezuma County's own 28°F hard-freeze dates and its ~166-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Montezuma CountyUSDA NRCS SSURGO
- 207 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.2 miles outFederal environmental registers
- Montezuma County's boundary and the 1,298,782 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 2 ecoregions Montezuma County spans, Colorado Plateaus the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Montezuma County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Montezuma County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Colorado grower plans around — written at state scale, so they stay on the state guidefrom Colorado
What this page can’t tell you
- How the season shifts across Montezuma County — the ~166 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 Montezuma County's 1,298,782 acreswhy one lot differs from the next →
- Which of those 207 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 Montezuma Countyread your own land →