Colfax County, in New Mexico, 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.
Colfax County lies within the Taos & the Sangre de Cristo High Country — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Colfax County holds more than one microclimate.
Soils and elevations shift across Colfax 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 Colfax County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Colfax County — the short answer
Colfax County, New Mexico: USDA zone 6a, about 163 days between hard freezes, across 2.4M acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 29
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 9
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~163
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 2.4M 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 Colfax County's average, not your lot's — a low corner or a tree line moves it. Against Colfax County's 163-day season, see what your own ground reads.
Heat in Colfax County
Across a year, Colfax County accumulates about 2,303 growing degree days above 50°F, about 870 fewer than the middle New Mexico county — ahead of 7 of New Mexico’s 33 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 Colfax County
Across Colfax County, the ground is predominantly Mollisols, where Fuera, Dargol, and Vamer are the most extensive named soil series. The soil is generally well drained with a stony loam surface. Topsoil pH runs about 6.7–7.2, neutral. Rainfall drains through hydrologic group D soils.
Soil order
Mollisols
Drainage
Well drained
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Colfax County
The USDA soil survey maps 97% of Colfax County as well drained — but another 2% drains differently: 2% moderately well drained.
Fuera is the most extensive named soil at 8% of mapped acres, then Dargol (8%) and Vamer (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 Colfax County
Each reading below is measured for Colfax 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 Colfax 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 Colfax County runs about pH 6.7–7.2, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredColfax County runs about 163 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
MeasuredColfax 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 Colfax County is in
Colfax County spans 2 EPA Level III ecoregions — Southern Rockies (49%) and Southwestern Tablelands (46%). 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 Colfax County
We scored all 1,086 plants against Colfax County's own USDA zone 6a and its own 163-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 New Mexico profile.
Is it too late to plant in Colfax County?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Apr 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 29 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 9 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
Documented around Colfax County
- monarch butterfly1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Colfax County
USGS estimates 11,813 lb of 2,4-d on Colfax County farmland in 2019, its largest by weight, ahead of Dicamba (5,442 lb) and Glyphosate (2,076 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 Colfax County — and how to grow with it.
We checked the federal record across Colfax County — 167 documented sites across 7 of the 9 source types we track.
The most significant on record: 2 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 Colfax 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 Colfax County
Closest first, across Colfax County. Listing isn't leaking, and distance isn't exposure.
- Maxwell NWR-North well, north playa below Lake 13Nitrate · 4.2 mi
- Maxwell NWR-West well, south playa below Lake 13Nitrate · 5.1 mi
- Maxwell NWR-North well, south playa below Lake 13Nitrate · 5.1 mi
- Maxwell NWR-East well, south playa below Lake 13Nitrate · 5.2 mi
- NATIONAL GUARD ARMORY RATONUnderground Storage Tanks · 7.0 mi
- MAXWELL GULFUnderground Storage Tanks · 7.1 mi
- MAXWELL NATIONAL WILDLIFE REFUGEUnderground Storage Tanks · 7.2 mi
- BRAGGS CONOCOUnderground Storage Tanks · 7.3 mi
- MAXWELL STATIONUnderground Storage Tanks · 7.4 mi
- RATON MUNICIPAL AIRPORTUnderground Storage Tanks · 10.5 mi
- OLD PATROL YARDUnderground Storage Tanks · 11.1 mi
- RUSSELLS TRUCK AND TRAVEL CENTERUnderground Storage Tanks · 11.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Colfax 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 Colfax County.
Total Sites
167
across Colfax County
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
across Colfax County
Severity Distribution
across Colfax County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Colfax County, two things run higher than the national average across Colfax County — Mining (21 sites) and PFAS (3 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.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Colfax 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 Colfax County average
Your land is one point inside Colfax County
Everything above resolves to Colfax County as a whole — one PHZM band and one county frost record, read across 2.4M 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 Colfax County Average
Colfax County Average
- ●USDA Zones 6a, averaged across Colfax County
- ●One soil character for all of Colfax County
- ●Frost dates read at Colfax County's scale: Apr 29 to Oct 9
YOUR Parcel
- ✓Your exact zone, not Colfax County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Colfax County
Pull a site-specific report for your exact address in Colfax County, New Mexico — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Colfax County averages can't show:
We read public map data around Colfax County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Colfax County average
How we know this about Colfax 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 Colfax County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Colfax County
When does frost risk typically end in Colfax County?
The last hard freeze (28°F) in Colfax County typically lands around Apr 29, 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 20.
How long is the growing season in Colfax County?
Measured between 28°F hard freezes, Colfax County sees about 163 frost-free days — roughly Apr 29 through Oct 9, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 20 to Sep 25, about 128 days.
Is the soil safe to grow vegetables in Colfax County?
The federal record around Colfax County is a meaningful one — 167 documented sites, mostly Underground Storage Tanks entries (100), the nearest Nitrate record about 4.2 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 Colfax County's scale — its 6a band and its 163-day season. Your yard writes its own version of Colfax 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 New Mexico's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Colfax County’s own scale
9 of the readings below were taken at Colfax County's own scale — its own ~163-day span between 28°F freezes, the 3 most extensive soil series mapped here and 167 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Colfax County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Colfax County's own 28°F hard-freeze dates and its ~163-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Colfax CountyUSDA NRCS SSURGO
- 167 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 4.2 miles outFederal environmental registers
- Colfax County's boundary and the 2,405,103 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~163-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Colfax County spans, Southern Rockies the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Colfax County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Colfax County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every New Mexico grower plans around — written at state scale, so they stay on the state guidefrom New Mexico
What this page can’t tell you
- How the season shifts across Colfax County — the ~163 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 Colfax County's 2,405,103 acreswhy one lot differs from the next →
- Which of those 167 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 Colfax Countyread your own land →