Montrose County, in Colorado, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
The conditions favor cabbage, blackberry, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Montrose County lies within the Uncompahgre Valley — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Montrose County holds more than one microclimate.
Soils and elevations shift across Montrose 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 Montrose County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Montrose County — the short answer
Montrose County, Colorado: USDA zone 6a, about 130 days between hard freezes, across 1.4M acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 23
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Sep 30
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~130
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 1.4M 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 Montrose County's average, not your lot's — a low corner or a tree line moves it. Against Montrose County's 130-day season, see what your own ground reads.
Heat in Montrose County
Across a year, Montrose County accumulates about 1,304 growing degree days above 50°F, about 528 fewer than the middle Colorado county — ahead of 26 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 Montrose County
Across Montrose County, the ground is predominantly Aridisols, where Cerro, Mesa, and Agua Fria are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 7.2–8.0, slightly alkaline. Rainfall drains through hydrologic group C soils.
Soil order
Aridisols
Drainage
Well drained
Hydric soils
4%
Soil still varies lot by lot — soil types explained.
How the ground varies across Montrose County
The USDA soil survey maps 92% of Montrose County as well drained — but another 4% drains differently: 1% very poorly drained, 1% somewhat poorly drained.
Cerro is the most extensive named soil at 7% of mapped acres, then Mesa (7%) and Agua Fria (5%).
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 Montrose County
Each reading below is measured for Montrose 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 Montrose County are well drained, in hydrologic group C — 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 Montrose County runs about pH 7.2–8.0, 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
MeasuredMontrose County runs about 130 days between hard freezes — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredMontrose 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 Montrose County is in
Montrose County spans 2 EPA Level III ecoregions — Colorado Plateaus (75%) and Southern Rockies (25%). 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 Montrose County
We scored all 1,086 plants against Montrose County's own USDA zone 6a and its own 130-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 Montrose 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 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 30 — long-season crops need about 90 days of runway, quick greens only 30. Short seasons reward decisiveness — quick-maturing varieties late, hardy greens under cover, and next year’s garlic in the ground before it closes.
Documented around Montrose County
- monarch butterfly1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Montrose County
USGS estimates 32,190 lb of Glyphosate on Montrose County farmland in 2019, its largest by weight, ahead of Dicamba (8,257 lb) and Atrazine (5,933 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 Montrose County — and how to grow with it.
We checked the federal record across Montrose County — 310 documented sites across 7 of the 9 source types we track.
The most significant on record: 4 Superfund sites. 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 Montrose 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 Montrose County
Closest first, across Montrose County. Listing isn't leaking, and distance isn't exposure.
- Copper King MineMining · 9.1 mi
- DELTA CITY OFPFAS · 16.0 mi
- Williams ConstructionUnderground Storage Tanks · 16.9 mi
- TRI-STATE GENERATION & TRANSMISSION - NUCLA STATIONToxics Release Inventory · 17.5 mi
- TRI-STATE GENERATION & TRANSMISSION - NUCLA STATIONBrownfields · 17.5 mi
- NUCLA ASH DISPOSAL SITEToxics Release Inventory · 17.5 mi
- NB04901023DCA-WOERNERNitrate · 17.9 mi
- NB04901026AAA-COMBSNitrate · 18.1 mi
- San Miguel Power AssocUnderground Storage Tanks · 18.2 mi
- West End Auto ServiceUnderground Storage Tanks · 18.2 mi
- WESTERN FUELS COMPANY NEW HORIZONBrownfields · 18.5 mi
- WESTERN FUELS COMPANY NEW HORIZONToxics Release Inventory · 18.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Montrose 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 Montrose County.
Sources Checked
across Montrose County
Severity Distribution
across Montrose County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Montrose County, two things run higher than the national average across Montrose County — Mining (35 sites) and Superfund (4 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.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Montrose 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 Montrose County average
Your land is one point inside Montrose County
Everything above resolves to Montrose County as a whole — one PHZM band and one county frost record, read across 1.4M 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 Montrose County Average
Montrose County Average
- ●USDA Zones 6a, averaged across Montrose County
- ●One soil character for all of Montrose County
- ●Frost dates read at Montrose County's scale: May 23 to Sep 30
YOUR Parcel
- ✓Your exact zone, not Montrose County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Montrose County
Pull a site-specific report for your exact address in Montrose County, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Montrose County averages can't show:
We read public map data around Montrose County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Montrose County average
How we know this about Montrose 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 Montrose County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Montrose County
When does frost risk typically end in Montrose County?
The last hard freeze (28°F) in Montrose County typically lands around May 23, 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 13.
How long is the growing season in Montrose County?
Measured between 28°F hard freezes, Montrose County sees about 130 frost-free days — roughly May 23 through Sep 30, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 13 to Sep 16, about 95 days.
Is the soil safe to grow vegetables in Montrose County?
The federal record around Montrose County is a meaningful one — 310 documented sites, mostly Underground Storage Tanks entries (126), the nearest Mining record about 9.1 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.
How do gardeners stretch the season in Montrose County?
With about 130 frost-free days between hard freezes, Montrose County rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 158 to 186 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 23 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Montrose County's scale — its 6a band and its 130-day season. Your yard writes its own version of Montrose 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 Montrose County’s own scale
9 of the readings below were taken at Montrose County's own scale — its own ~130-day span between 28°F freezes, the 3 most extensive soil series mapped here and 310 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Montrose County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Montrose County's own 28°F hard-freeze dates and its ~130-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Montrose CountyUSDA NRCS SSURGO
- 310 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Mining record about 9.1 miles outFederal environmental registers
- Montrose County's boundary and the 1,434,204 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~130-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Montrose County spans, Colorado Plateaus the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Montrose County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Montrose 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 Montrose County — the ~130 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 Montrose County's 1,434,204 acreswhy one lot differs from the next →
- Which of those 310 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 Montrose Countyread your own land →