Blue River, Colorado, sits in USDA hardiness zone 5a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
A short list that earns its place here — pumpkin, cranberry, lavender, and zucchini — with any one site's soil, sun, and drainage making the final cut.
Even in Blue River, 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 Blue River 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 Blue River — soil, climate, flood, and parcel records. How we handle your address.
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Blue River — the short answer
Blue River, Colorado: USDA zone 5a, about 105 days between hard freezes, across 2K acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jun 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~105
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 2K 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 Blue River's average, not your lot's — a low corner or a tree line moves it. Against Blue River's 105-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Blue River
Each reading below is measured for Blue River itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredBlue River runs about 105 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
MeasuredBlue River 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 Blue River is in
Blue River sits in the Southern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Blue River's own centroid rather than borrowed from Summit County.
What Grows in Blue River
Every plant below cleared Blue River's own zone 5a and its 105-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Blue River?
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 17 — 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's on the federal record near Blue River
Closest first, within ~10 miles of Blue River. Listing isn't leaking, and distance isn't exposure.
- Gold Nugget PlacerMining · 0.7 mi
- UnknownMining · 0.9 mi
- PlayerMining · 1.3 mi
- GermaniaMining · 1.3 mi
- DeweyMining · 1.4 mi
- Pacific-Gold DustMining · 1.5 mi
- Barn Store #22Underground Storage Tanks · 1.6 mi
- Dunkin, Juniata, Puzzle, Ouray, Gold Dust, WashingtonMining · 1.6 mi
- DunkinMining · 1.6 mi
- Commodore PlacerMining · 1.7 mi
- MaxwellMining · 1.7 mi
- SilenceMining · 1.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Blue River'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 Blue River.
Total Sites
329
within ~10 miles of Blue River
Risk Level
High
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Blue River
Severity Distribution
within ~10 miles of Blue River
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Blue River, two things run higher than the national average within ~10 miles of Blue River — Mining (253 sites) and PFAS (3 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.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Blue River
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 Blue River average
Your land is one point inside Blue River
Everything above resolves to Blue River as a whole — one PHZM band and one 28°F frost record, read across 2K 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 Blue River Average
Blue River Average
- ●USDA Zones 5a, averaged across Blue River
- ●One soil character for all of Blue River
- ●Frost dates read at Blue River's scale: Jun 4 to Sep 17
YOUR Parcel
- ✓Your exact zone, not Blue River's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Blue River
Pull a site-specific report for your exact address in Blue River, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Blue River averages can't show:
We read public map data around Blue River — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Blue River average
How we know this about Blue River
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 Blue River’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 Blue River
When does frost risk typically end in Blue River?
The last hard freeze (28°F) in Blue River 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.
When is the first frost in Blue River?
The first hard freeze (28°F) in Blue River typically arrives around Sep 17, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 3, so the watching starts about Aug 18 — about 105 days after the spring freeze cleared.
How long is the growing season in Blue River?
Measured between 28°F hard freezes, Blue River sees about 105 frost-free days — roughly Jun 4 through Sep 17, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 25 to Sep 3, about 70 days.
Is the soil safe to grow vegetables in Blue River?
The federal record around Blue River runs heavier than most — 329 documented sites, mostly Mining entries (253), the nearest Mining 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 Blue River?
With about 105 frost-free days between hard freezes, Blue River 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 133 to 161 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 Blue River's scale — its 5a band and its 105-day season. Your yard writes its own version of Blue River'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 Blue River’s own scale
6 of the readings below were taken at Blue River's own scale — its own ~105-day season between 28°F freezes, the 1,558 acres it covers and 329 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Blue River's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Blue River's own 28°F hard-freeze dates, about Jun 4 and Sep 17 and the ~105-day span between themNOAA 1991–2020 Climate Normals
- 329 documented contamination sites on the federal record near Blue River, the closest Mining record about 0.7 miles out from the town centreFederal environmental registers
- Blue River's boundary and the 1,558 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~105-day seasonGrowable Ground crop-matching engine
- The ecoregion at Blue River's own centroid, the Southern RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Blue River's 1,558 acres read through its county's SSURGO summaryfrom Summit County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Summit 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 Summit County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Blue River's 1,558 acreswhy one lot differs from the next →
- Which side of Blue River you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,558 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Mining 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 Blue River-wide figureread your own land →