Clear Creek County, in Colorado, sits in USDA hardiness zone 5a — a zone band wide enough that plant choice, not possibility, is the interesting question.
On paper, colorado blue spruce, tomato, penstemon, and apple all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Clear Creek County holds more than one microclimate.
Soils and elevations shift across Clear Creek County, so your frost dates and drainage aren't the county average. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Quick Facts
USDA Zones
5a
Last Hard Freeze (28°F)
May 13
County normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Oct 6
County normal — light frosts arrive a few weeks earlier
County Area
253K acres
Hardiness Zone Range
Zone maps are averages across Clear Creek County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Clear Creek County
Across Clear Creek County, the ground is predominantly Inceptisols, where Legault, Ohman, and Cathedral are the most extensive named soil series. The soil is generally somewhat excessively drained with a cobbly silt loam surface. Topsoil pH runs about 5.8–6.1, moderately acidic. Rainfall drains through hydrologic group D soils.
Soil order
Inceptisols
Drainage
Somewhat excessively drained
Hydric soils
4%
Soil still varies lot by lot — soil types explained.
What Grows in Clear Creek County
Plants matched to Clear Creek County's USDA zones 5a — each links to its full growing profile.
Is it too late to plant in Clear Creek County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Apr 15; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 6 — 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.
Growing Challenges in Colorado
What an experienced grower plans around here — each one has a move.
Low annual rainfall (7-20 inches) means irrigation is essential nearly everywhere
Build the irrigation first — drip plus mulch makes a high-desert garden run on remarkably little water.
High altitude UV and temperature swings stress plants
Harden transplants gradually, shade-cloth their first high-sun week, and keep row covers handy for cold nights.
Very short growing season at elevation (60-90 frost-free days above 8,000 ft)
Above 8,000 feet, count your real frost-free days and choose varieties bred to finish inside them.
Alkaline soils (pH 7.5-8.5) limit acid-loving plants without amendment
A soil test tells you your actual pH — grow acid-lovers in containers of amended mix while the native ground grows everything else.
For cultivar selection, pest pressure, and planting-time guidance specific to Colorado, the Colorado State University Extension is the authoritative local source.
Safe to Grow Here?
What the federal record shows across Clear Creek County — and how to grow with it.
We checked the federal record across Clear Creek County — 584 documented sites across 7 of the 9 source types we track.
The most significant on record: 6 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Clear Creek 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.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Sources Checked
across Clear Creek County
Severity Distribution
across Clear Creek County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Clear Creek County, Mining runs higher than the national average — 495 sites nearby. 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 Clear Creek County
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Clear Creek County Average
- ●USDA Zones 5a
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Clear Creek County
Pull a site-specific report for your exact address in Clear Creek County, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Clear Creek County, Colorado
- USDA Hardiness Zones: 5a (USDA PHZM 2023)
- Last Hard Freeze (28°F): May 13 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Oct 6 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~146 (county normal, NOAA 1991–2020 Climate Normals)
- County Land Area: 253K acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. County boundaries: US Census TIGER/Line 2025.
Frost dates here are the Clear Creek County average. Low spots and tree cover move them by days on any one yard — see your exact frost windows.
Frequently Asked Questions
What hardiness zone is Clear Creek County, Colorado?
Clear Creek County sits in USDA hardiness zone 5a, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
Is it too late to plant in Clear Creek County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Apr 15; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 6 — 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.
When does frost risk typically end in Clear Creek County?
The last hard freeze (28°F) in Clear Creek County typically lands around May 13, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.
How long is the growing season in Clear Creek County?
Measured between 28°F hard freezes, Clear Creek County sees about 146 frost-free days — roughly May 13 through Oct 6, per NOAA 1991–2020 climate normals. Tender crops get a somewhat shorter practical window, since lighter frosts reach a few weeks past the hard-freeze dates on both ends.
What vegetables grow in Clear Creek County?
Clear Creek County's zone 5a supports a wide range — strong performers include Colorado Blue Spruce, Tomato, Penstemon, Apple, and Peach. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Clear Creek County, really?
Officially, Clear Creek County sits in USDA zone 5a (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Clear Creek County?
The federal record around Clear Creek County runs heavier than most — 584 documented sites — 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 Clear Creek County?
With about 146 frost-free days between hard freezes, Clear Creek County rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder, cold frames and low tunnels more, and quick-maturing varieties make the arithmetic work. Starting transplants indoors ahead of the May 13 hard-freeze normal stretches the season without touching the calendar.
Everything on this page is a Clear Creek County average. Your yard writes its own version — 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.