Alpine, Colorado, sits in USDA hardiness zone 5a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Among the crops suited to this profile: okra, cranberry, lavender, and pumpkin. The site-level story — soil, sun, drainage — decides the rest.
Even in Alpine, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Alpine lot. 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 Alpine — soil, climate, flood, and parcel records. How we handle your address.
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Alpine — the short answer
Alpine, Colorado: USDA zone 5a, about 114 days between hard freezes, across 673 acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 31
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~114
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 673 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 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 5a is Alpine's average, not your lot's — a low corner or a tree line moves it. Against Alpine's 114-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Alpine
Each reading below is measured for Alpine itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredAlpine runs about 114 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
MeasuredAlpine sits in USDA hardiness zone 5a.
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 Alpine is in
Alpine sits in the Southern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Alpine's own centroid rather than borrowed from Rio Grande County.
What Grows in Alpine
Every plant below cleared Alpine's own zone 5a and its 114-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Alpine?
Almost never — the real question is what to plant next. Cool-season crops can go in from around May 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 31 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 22 — 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's on the federal record near Alpine
Closest first, within ~10 miles of Alpine. Listing isn't leaking, and distance isn't exposure.
- Rio Grande County Road DepartmentUnderground Storage Tanks · 0.7 mi
- Wolf Creek RanchUnderground Storage Tanks · 1.2 mi
- AT&T South Fork RsUnderground Storage Tanks · 1.9 mi
- AT&T SOUTH FORKBrownfields · 2.0 mi
- Jackson Lumber CoUnderground Storage Tanks · 2.1 mi
- Twin Pine Motor SportsUnderground Storage Tanks · 2.1 mi
- Stone Forest Industries IncUnderground Storage Tanks · 2.5 mi
- Chinook Store & MotelUnderground Storage Tanks · 2.6 mi
- Rainbow ExpressUnderground Storage Tanks · 3.1 mi
- CDOT South ForkUnderground Storage Tanks · 3.2 mi
- The Whistle PigUnderground Storage Tanks · 3.4 mi
- AT&Twolf Creek Pass RsUnderground Storage Tanks · 4.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Alpine'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 Alpine.
Total Sites
37
within ~10 miles of Alpine
Risk Level
High
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Alpine
Severity Distribution
within ~10 miles of Alpine
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Alpine, Mining runs higher than the national average — 22 sites within ~10 miles of Alpine. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around 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 Alpine
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 Alpine average
Your land is one point inside Alpine
Everything above resolves to Alpine as a whole — one PHZM band and one 28°F frost record, read across 673 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 town 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 local average.
Your Lot vs the Alpine Average
Alpine Average
- ●USDA Zones 5a, averaged across Alpine
- ●One soil character for all of Alpine
- ●Frost dates read at Alpine's scale: May 31 to Sep 22
YOUR Parcel
- ✓Your exact zone, not Alpine's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Alpine
Pull a site-specific report for your exact address in Alpine, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Alpine averages can't show:
We read public map data around Alpine — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Alpine average
How we know this about Alpine
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Alpine’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Alpine
When does frost risk typically end in Alpine?
The last hard freeze (28°F) in Alpine typically lands around May 31, 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 21.
When is the first frost in Alpine?
The first hard freeze (28°F) in Alpine typically arrives around Sep 22, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 8, so the watching starts about Aug 23 — about 114 days after the spring freeze cleared.
How long is the growing season in Alpine?
Measured between 28°F hard freezes, Alpine sees about 114 frost-free days — roughly May 31 through Sep 22, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 21 to Sep 8, about 79 days.
Is the soil safe to grow vegetables in Alpine?
The federal record around Alpine runs heavier than most — 37 documented sites, mostly Mining entries (22), the nearest Underground Storage Tanks record about 0.7 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 Alpine?
With about 114 frost-free days between hard freezes, Alpine 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 142 to 170 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 31 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Alpine's scale — its 5a band and its 114-day season. Your yard writes its own version of Alpine's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Alpine’s own scale
6 of the readings below were taken at Alpine's own scale — its own ~114-day season between 28°F freezes, the 673 acres it covers and 37 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Alpine's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Alpine's own 28°F hard-freeze dates, about May 31 and Sep 22 and the ~114-day span between themNOAA 1991–2020 Climate Normals
- 37 documented contamination sites on the federal record near Alpine, the closest Underground Storage Tanks record about 0.7 miles out from the town centreFederal environmental registers
- Alpine's boundary and the 673 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~114-day seasonGrowable Ground crop-matching engine
- The ecoregion at Alpine's own centroid, the Southern RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Alpine's 673 acres read through its county's SSURGO summaryfrom Rio Grande County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Rio Grande County
- The growing challenges every Colorado grower plans around — written at state scale, so they stay on the state guidefrom Colorado
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Rio Grande County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Alpine's 673 acreswhy one lot differs from the next →
- Which side of Alpine you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 673 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.7 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Alpine-wide figureread your own land →
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