Mineral County, in Colorado, sits in USDA hardiness zone 5b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Reliable performers under these conditions include pumpkin, blackberry, lavender, and zucchini; what your own ground favors still comes down to its soil, sun, and drainage.
Mineral 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
Mineral County holds more than one microclimate.
Soils and elevations shift across Mineral 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 Mineral County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Mineral County — the short answer
Mineral County, Colorado: USDA zone 5b, about 109 days between hard freezes, across 560K acres.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jun 4
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Sep 21
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~109
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 560K 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 Mineral County's average, not your lot's — a low corner or a tree line moves it. Against Mineral County's 109-day season, see what your own ground reads.
Heat in Mineral County
Across a year, Mineral County accumulates about 94 growing degree days above 50°F, about 1,738 fewer than the middle Colorado county — ahead of 1 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 Mineral County
Detailed USDA soil-survey (SSURGO) mapping is limited across Mineral County, so there isn't a reliable county-wide soil summary to show here yet — a gap in the national survey, not in the ground itself.
Soil still varies lot by lot — soil types explained.
What this means for growing in Mineral County
Each reading below is measured for Mineral County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMineral County runs about 109 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
MeasuredMineral 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 Mineral County is in
Mineral County sits in the Southern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. One consistent ecological setting across the whole county.
What Grows in Mineral County
We scored all 1,086 plants against Mineral County's own USDA zone 5b and its own 109-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 Mineral County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around May 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jun 4 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 21 — long-season crops need about 90 days of runway, quick greens only 30. Even here the calendar’s edges hold value: thirty-day greens late in the window, then garlic and a rested bed for spring.
What gets applied to farmland in Mineral County
USGS estimates 76 lb of Glyphosate on Mineral County farmland in 2019, its largest by weight, ahead of Diuron (74 lb) and 2,4-d (54 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 Mineral County — and how to grow with it.
We checked the federal record across Mineral County — 109 documented sites across 4 of the 9 source types we track.
The most significant on record: 5 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Mineral 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 Mineral County
Closest first, across Mineral County. Listing isn't leaking, and distance isn't exposure.
- Piedra Peak-Red Mountain Alunite DepositsMining · 2.2 mi
- Emma MineMining · 9.8 mi
- Denver TunnelMining · 10.2 mi
- EmmaMining · 10.2 mi
- Bird Creek MineMining · 10.7 mi
- Royal Arch DistrictMining · 11.0 mi
- Spar CityMining · 11.1 mi
- CREEDE CITY OFPFAS · 11.7 mi
- CDOT Wolf CreekUnderground Storage Tanks · 12.6 mi
- Wolf Creek Ski AreaUnderground Storage Tanks · 12.7 mi
- CDOT CreedeUnderground Storage Tanks · 15.5 mi
- Tyrus B PoxsonUnderground Storage Tanks · 15.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Mineral 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 Mineral County.
Sources Checked
across Mineral County
Severity Distribution
across Mineral County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Mineral County, two things run higher than the national average across Mineral County — Mining (95 sites) and Superfund (5 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 Mineral 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 Mineral County average
Your land is one point inside Mineral County
Everything above resolves to Mineral County as a whole — one PHZM band and one county frost record, read across 560K 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 Mineral County Average
Mineral County Average
- ●USDA Zones 5b, averaged across Mineral County
- ●One soil character for all of Mineral County
- ●Frost dates read at Mineral County's scale: Jun 4 to Sep 21
YOUR Parcel
- ✓Your exact zone, not Mineral County's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Mineral County
Pull a site-specific report for your exact address in Mineral County, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Mineral County averages can't show:
We read public map data around Mineral County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Mineral County average
How we know this about Mineral 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 Mineral County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Mineral County
When does frost risk typically end in Mineral County?
The last hard freeze (28°F) in Mineral County typically lands around Jun 4, 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 25.
How long is the growing season in Mineral County?
Measured between 28°F hard freezes, Mineral County sees about 109 frost-free days — roughly Jun 4 through Sep 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 25 to Sep 7, about 74 days.
Is the soil safe to grow vegetables in Mineral County?
The federal record around Mineral County runs heavier than most — 109 documented sites, mostly Mining entries (95), the nearest Mining record about 2.2 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 Mineral County?
With about 109 frost-free days between hard freezes, Mineral 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 137 to 165 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the Jun 4 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Mineral County's scale — its 5b band and its 109-day season. Your yard writes its own version of Mineral 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 Mineral County’s own scale
7 of the readings below were taken at Mineral County's own scale — its own ~109-day span between 28°F freezes and 109 documented sites inside its boundary; 2 are borrowed from a wider read, named and linked below.
Measured here
- Mineral County's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Mineral County's own 28°F hard-freeze dates and its ~109-day span between themNOAA 1991–2020 Climate Normals
- 109 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Mining record about 2.2 miles outFederal environmental registers
- Mineral County's boundary and the 560,486 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~109-day seasonGrowable Ground crop-matching engine
- Mineral County sitting wholly inside the Southern RockiesUS EPA Level III Ecoregions
- Which agricultural compounds go onto Mineral County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
What this page can’t tell you
- How the season shifts across Mineral County — the ~109 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 Mineral County's 560,486 acreswhy one lot differs from the next →
- Which of those 109 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 Mineral Countyread your own land →