Grand Lake, Colorado, sits in USDA hardiness zone 4b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
On paper, okra, cranberry, cilantro, and zucchini all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Grand Lake, 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 Grand Lake 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 Grand Lake — soil, climate, flood, and parcel records. How we handle your address.
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Grand Lake — the short answer
Grand Lake, Colorado: USDA zone 4b, about 110 days between hard freezes, across 660 acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jun 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 19
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~110
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 660 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 4b is Grand Lake's average, not your lot's — a low corner or a tree line moves it. Against Grand Lake's 110-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Grand Lake
Each reading below is measured for Grand Lake itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGrand Lake runs about 110 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
MeasuredGrand Lake sits in USDA hardiness zone 4b.
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 Grand Lake is in
Grand Lake sits in the Southern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Grand Lake's own centroid rather than borrowed from Grand County.
What Grows in Grand Lake
Every plant below cleared Grand Lake's own zone 4b and its 110-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Grand Lake?
Almost never — the real question is what to plant next. Cool-season crops can go in from around May 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jun 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 19 — long-season crops need about 90 days of runway, quick greens only 30. Short seasons reward decisiveness — quick-maturing varieties late, hardy greens under cover, and next year’s garlic in the ground before it closes.
What's on the federal record near Grand Lake
Closest first, within ~10 miles of Grand Lake. Listing isn't leaking, and distance isn't exposure.
- Grand Lumber CoUnderground Storage Tanks · 1900 ft
- Lone Eagle StationUnderground Storage Tanks · 1900 ft
- Grand Lake ElementaryUnderground Storage Tanks · 2000 ft
- The Overland StaUnderground Storage Tanks · 2200 ft
- Warren RamlerUnderground Storage Tanks · 2200 ft
- Town Of Grand LakeUnderground Storage Tanks · 2400 ft
- City Of Grand LakeUnderground Storage Tanks · 2500 ft
- Jeremiah & Beverly Beal TrustUnderground Storage Tanks · 0.5 mi
- Rocky Mountain National ParkUnderground Storage Tanks · 0.7 mi
- SB00307506BCB00Nitrate · 0.7 mi
- Lakeview General StoreUnderground Storage Tanks · 0.7 mi
- Lake Kove MarinaUnderground Storage Tanks · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Grand Lake'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 Grand Lake.
Sources Checked
within ~10 miles of Grand Lake
Severity Distribution
within ~10 miles of Grand Lake
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Grand Lake, two things run higher than the national average within ~10 miles of Grand Lake — Nitrate (16 sites) and Mining (3 sites). That's not a problem with your land — it's information about it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
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 well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Grand Lake
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 Grand Lake average
Your land is one point inside Grand Lake
Everything above resolves to Grand Lake as a whole — one PHZM band and one 28°F frost record, read across 660 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 Grand Lake Average
Grand Lake Average
- ●USDA Zones 4b, averaged across Grand Lake
- ●One soil character for all of Grand Lake
- ●Frost dates read at Grand Lake's scale: Jun 1 to Sep 19
YOUR Parcel
- ✓Your exact zone, not Grand Lake's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Grand Lake
Pull a site-specific report for your exact address in Grand Lake, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Grand Lake averages can't show:
We read public map data around Grand Lake — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Grand Lake average
How we know this about Grand Lake
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 Grand Lake’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 Grand Lake
When does frost risk typically end in Grand Lake?
The last hard freeze (28°F) in Grand Lake typically lands around Jun 1, 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 22.
When is the first frost in Grand Lake?
The first hard freeze (28°F) in Grand Lake typically arrives around Sep 19, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 5, so the watching starts about Aug 20 — about 110 days after the spring freeze cleared.
How long is the growing season in Grand Lake?
Measured between 28°F hard freezes, Grand Lake sees about 110 frost-free days — roughly Jun 1 through Sep 19, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 22 to Sep 5, about 75 days.
Is the soil safe to grow vegetables in Grand Lake?
The federal record around Grand Lake shows 48 documented sites, mostly Underground Storage Tanks entries (26), the nearest Underground Storage Tanks record about 0.4 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do gardeners stretch the season in Grand Lake?
With about 110 frost-free days between hard freezes, Grand Lake 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 138 to 166 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the Jun 1 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Grand Lake's scale — its 4b band and its 110-day season. Your yard writes its own version of Grand Lake'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 Grand Lake’s own scale
6 of the readings below were taken at Grand Lake's own scale — its own ~110-day season between 28°F freezes, the 660 acres it covers and 48 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Grand Lake's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Grand Lake's own 28°F hard-freeze dates, about Jun 1 and Sep 19 and the ~110-day span between themNOAA 1991–2020 Climate Normals
- 48 documented contamination sites on the federal record near Grand Lake, the closest Underground Storage Tanks record about 0.4 miles out from the town centreFederal environmental registers
- Grand Lake's boundary and the 660 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~110-day seasonGrowable Ground crop-matching engine
- The ecoregion at Grand Lake's own centroid, the Southern RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Grand Lake's 660 acres read through its county's SSURGO summaryfrom Grand County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Grand 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 Grand County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Grand Lake's 660 acreswhy one lot differs from the next →
- Which side of Grand Lake you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 660 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.4 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 Grand Lake-wide figureread your own land →