Gilpin 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.
These conditions suit okra, cranberry, lavender, and pumpkin — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Gilpin County lies within the Colorado High Country (Central Rockies) — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Gilpin County holds more than one microclimate.
Soils and elevations shift across Gilpin 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 Gilpin County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Gilpin County — the short answer
Gilpin County, Colorado: USDA zone 5b, about 118 days between hard freezes, across 96K acres.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 30
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Sep 25
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~118
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 96K 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 Gilpin County's average, not your lot's — a low corner or a tree line moves it. Against Gilpin County's 118-day season, see what your own ground reads.
Heat in Gilpin County
Across a year, Gilpin County accumulates about 381 growing degree days above 50°F, about 1,451 fewer than the middle Colorado county — ahead of 7 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 Gilpin County
Across Gilpin County, the ground is predominantly Inceptisols, where Legault, Resort, and Cathedral are the most extensive named soil series. The soil is generally well drained with a very gravelly sandy loam surface. Topsoil pH runs about 6.0–6.5, slightly acidic. Rainfall drains through hydrologic group D soils.
Soil order
Inceptisols
Drainage
Well drained
Hydric soils
4%
Soil still varies lot by lot — soil types explained.
How the ground varies across Gilpin County
The USDA soil survey maps 48% of Gilpin County as well drained — but another 50% drains differently: 42% somewhat excessively drained, 4% excessively drained.
Legault is the most extensive named soil at 15% of mapped acres, then Resort (6%) and Cathedral (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 Gilpin County
Each reading below is measured for Gilpin 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 Gilpin 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 Gilpin County runs about pH 6.0–6.5, 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
MeasuredGilpin County runs about 118 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
MeasuredGilpin 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 Gilpin County is in
Gilpin 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 Gilpin County
We scored all 1,086 plants against Gilpin County's own USDA zone 5b and its own 118-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 Gilpin 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 May 2; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 30 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 25 — 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.
Documented around Gilpin County
- monarch butterfly1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Gilpin County
USGS estimates 2,899 lb of Metolachlor-s on Gilpin County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (2,899 lb) and Glyphosate (2,047 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 Gilpin County — and how to grow with it.
We checked the federal record across Gilpin County — 279 documented sites across 5 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.
Gilpin 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 Gilpin County
Closest first, across Gilpin County. Listing isn't leaking, and distance isn't exposure.
- StewartMining · 900 ft
- PetuniaMining · 2000 ft
- Pine ConeMining · 2100 ft
- Julia LodeMining · 2400 ft
- Quincy Bart AltanticMining · 0.6 mi
- Golden FlintMining · 0.7 mi
- BennettMining · 0.7 mi
- Old KentuckyMining · 0.8 mi
- SnowdenMining · 0.9 mi
- Golden RodMining · 1.1 mi
- Velvet ValleyMining · 1.2 mi
- Ellis LodeMining · 1.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Gilpin 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 Gilpin County.
Sources Checked
across Gilpin County
Severity Distribution
across Gilpin County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Gilpin County, two things run higher than the national average across Gilpin County — Mining (252 sites) and Superfund (4 sites). 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.
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 Gilpin 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 Gilpin County average
Your land is one point inside Gilpin County
Everything above resolves to Gilpin County as a whole — one PHZM band and one county frost record, read across 96K 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 Gilpin County Average
Gilpin County Average
- ●USDA Zones 5b, averaged across Gilpin County
- ●One soil character for all of Gilpin County
- ●Frost dates read at Gilpin County's scale: May 30 to Sep 25
YOUR Parcel
- ✓Your exact zone, not Gilpin County's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Gilpin County
Pull a site-specific report for your exact address in Gilpin County, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Gilpin County averages can't show:
We read public map data around Gilpin County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Gilpin County average
How we know this about Gilpin 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 Gilpin County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Gilpin County
When does frost risk typically end in Gilpin County?
The last hard freeze (28°F) in Gilpin County typically lands around May 30, 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 20.
How long is the growing season in Gilpin County?
Measured between 28°F hard freezes, Gilpin County sees about 118 frost-free days — roughly May 30 through Sep 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 20 to Sep 11, about 83 days.
Is the soil safe to grow vegetables in Gilpin County?
The federal record around Gilpin County runs heavier than most — 279 documented sites, mostly Mining entries (252), the nearest Mining record about 0.2 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 Gilpin County?
With about 118 frost-free days between hard freezes, Gilpin 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 146 to 174 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 30 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Gilpin County's scale — its 5b band and its 118-day season. Your yard writes its own version of Gilpin 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 Gilpin County’s own scale
9 of the readings below were taken at Gilpin County's own scale — its own ~118-day span between 28°F freezes, the 3 most extensive soil series mapped here and 279 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Gilpin County's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Gilpin County's own 28°F hard-freeze dates and its ~118-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Gilpin CountyUSDA NRCS SSURGO
- 279 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Mining record about 0.2 miles outFederal environmental registers
- Gilpin County's boundary and the 96,014 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~118-day seasonGrowable Ground crop-matching engine
- Gilpin County sitting wholly inside the Southern RockiesUS EPA Level III Ecoregions
- Open occurrence records documented in Gilpin County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Gilpin 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 Gilpin County — the ~118 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 Gilpin County's 96,014 acreswhy one lot differs from the next →
- Which of those 279 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 Gilpin Countyread your own land →