Conejos County, in Colorado, sits in USDA hardiness zone 5b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Growers here do well with cabbage, cranberry, lavender, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Conejos County lies within the San Luis Valley — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Conejos County holds more than one microclimate.
Soils and elevations shift across Conejos 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 Conejos County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Conejos County — the short answer
Conejos County, Colorado: USDA zone 5b, about 137 days between hard freezes, across 824K acres.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 19
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 3
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~137
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 824K 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 5b is Conejos County's average, not your lot's — a low corner or a tree line moves it. Against Conejos County's 137-day season, see what your own ground reads.
Heat in Conejos County
Across a year, Conejos County accumulates about 1,017 growing degree days above 50°F, about 815 fewer than the middle Colorado county — ahead of 16 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 Conejos County
Across Conejos County, the ground is predominantly Aridisols, where Travelers, Garita, and Graypoint are the most extensive named soil series. The soil is generally well drained with a very stony loam surface. Topsoil pH runs about 7.5–8.2, slightly alkaline. Rainfall drains through hydrologic group D soils.
Soil order
Aridisols
Drainage
Well drained
Hydric soils
7%
Soil still varies lot by lot — soil types explained.
How the ground varies across Conejos County
The USDA soil survey maps 65% of Conejos County as well drained — but another 34% drains differently: 16% somewhat poorly drained, 9% poorly drained.
Travelers is the most extensive named soil at 22% of mapped acres, then Garita (13%) and Graypoint (10%).
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 Conejos County
Each reading below is measured for Conejos 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 Conejos 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 Conejos County runs about pH 7.5–8.2, 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
MeasuredConejos County runs about 137 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
MeasuredConejos County sits in USDA hardiness zone 5b.
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 Conejos County is in
Conejos County spans 2 EPA Level III ecoregions — Arizona/New Mexico Plateau (51%) and Southern Rockies (49%). 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 Conejos County
We scored all 1,086 plants against Conejos County's own USDA zone 5b and its own 137-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 Conejos County?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Apr 21; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 19 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 3 — long-season crops need about 90 days of runway, quick greens only 30. When the window is tight, the fall moves are quick ones — baby greens, radishes, and garlic set for next season.
What gets applied to farmland in Conejos County
USGS estimates 12,227 lb of Glyphosate on Conejos County farmland in 2019, its largest by weight, ahead of Metolachlor-s (5,621 lb) and Metolachlor & Metolachlor-s (5,621 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 Conejos County — and how to grow with it.
We checked the federal record across Conejos County — 106 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.
Conejos County 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.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Conejos County
Closest first, across Conejos County. Listing isn't leaking, and distance isn't exposure.
- Choke Cherry GeneralUnderground Storage Tanks · 6.0 mi
- NA03600835BCC2Nitrate · 9.3 mi
- NA03400929CBB3Nitrate · 9.4 mi
- NA03400929CBB2Nitrate · 9.4 mi
- NA03400929CBB6Nitrate · 9.4 mi
- NA03400929CBB5Nitrate · 9.4 mi
- NA03400929CBB4Nitrate · 9.4 mi
- ANTONITO TOWN OFPFAS · 9.6 mi
- LOBATOS SALVAGEBrownfields · 10.4 mi
- River Springs Guard StationUnderground Storage Tanks · 10.6 mi
- TMC INCBrownfields · 10.7 mi
- Romeo ServiceUnderground Storage Tanks · 10.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Conejos 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 Conejos County.
Sources Checked
across Conejos County
Severity Distribution
across Conejos County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Conejos County, two things run higher than the national average across Conejos County — Mining (25 sites) and Nitrate (34 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).
Check your specific parcel in Conejos 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 Conejos County average
Your land is one point inside Conejos County
Everything above resolves to Conejos County as a whole — one PHZM band and one county frost record, read across 824K 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 Conejos County Average
Conejos County Average
- ●USDA Zones 5b, averaged across Conejos County
- ●One soil character for all of Conejos County
- ●Frost dates read at Conejos County's scale: May 19 to Oct 3
YOUR Parcel
- ✓Your exact zone, not Conejos County's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Conejos County
Pull a site-specific report for your exact address in Conejos County, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Conejos County averages can't show:
We read public map data around Conejos County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Conejos County average
How we know this about Conejos 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 Conejos County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Conejos County
When does frost risk typically end in Conejos County?
The last hard freeze (28°F) in Conejos County typically lands around May 19, 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 9.
How long is the growing season in Conejos County?
Measured between 28°F hard freezes, Conejos County sees about 137 frost-free days — roughly May 19 through Oct 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 9 to Sep 19, about 102 days.
Is the soil safe to grow vegetables in Conejos County?
The federal record around Conejos County runs heavier than most — 106 documented sites, mostly Underground Storage Tanks entries (38), the nearest Underground Storage Tanks record about 6.0 miles out — 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.
How do gardeners stretch the season in Conejos County?
With about 137 frost-free days between hard freezes, Conejos 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 165 to 193 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 19 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Conejos County's scale — its 5b band and its 137-day season. Your yard writes its own version of Conejos 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 Conejos County’s own scale
8 of the readings below were taken at Conejos County's own scale — its own ~137-day span between 28°F freezes, the 3 most extensive soil series mapped here and 106 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Conejos County's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Conejos County's own 28°F hard-freeze dates and its ~137-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Conejos CountyUSDA NRCS SSURGO
- 106 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 6.0 miles outFederal environmental registers
- Conejos County's boundary and the 823,952 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~137-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Conejos County spans, Arizona/New Mexico Plateau the largestUS EPA Level III Ecoregions
- Which agricultural compounds go onto Conejos 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 Conejos County — the ~137 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 Conejos County's 823,952 acreswhy one lot differs from the next →
- Which of those 106 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 Conejos Countyread your own land →