Eldora, 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 cabbage, cranberry, lavender, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Eldora, 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 Eldora 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 Eldora — soil, climate, flood, and parcel records. How we handle your address.
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Eldora — the short answer
Eldora, Colorado: USDA zone 5b, about 123 days between hard freezes, across 3K acres of town.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~123
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 3K 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 5b is Eldora's average, not your lot's — a low corner or a tree line moves it. Against Eldora's 123-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Eldora
Each reading below is measured for Eldora itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredEldora runs about 123 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
MeasuredEldora 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 Eldora is in
Eldora sits in the Southern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Eldora's own centroid rather than borrowed from Boulder County.
What Grows in Eldora
Every plant below cleared Eldora's own zone 5b and its 123-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Eldora?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Apr 28; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 26 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 26 — 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 Eldora
Closest first, within ~10 miles of Eldora. Listing isn't leaking, and distance isn't exposure.
- SC00107320BADD SITE 019Nitrate · 0.5 mi
- SC00107320ACBC SITE 020Nitrate · 0.6 mi
- SC00107320ACBD SITE 051Nitrate · 0.6 mi
- SC00107320ADBC SITE 021Nitrate · 0.7 mi
- SC00107320ADBB SITE C09Nitrate · 0.7 mi
- SC00107321BCBC SITE 048Nitrate · 0.8 mi
- SC00107320ADDB SITE 052Nitrate · 0.8 mi
- SC00107321BCAC SITE 047Nitrate · 0.9 mi
- SC00107321BCAD SITE 049Nitrate · 1.0 mi
- SC00107321BCDB SITE 042Nitrate · 1.0 mi
- SC00107321BDCB SITE 050Nitrate · 1.0 mi
- SC00107321BDBA SITE 046Nitrate · 1.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Eldora'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 Eldora.
Sources Checked
within ~10 miles of Eldora
Severity Distribution
within ~10 miles of Eldora
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Eldora, two things run higher than the national average within ~10 miles of Eldora — Mining (128 sites) and Superfund (3 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Eldora
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 Eldora average
Your land is one point inside Eldora
Everything above resolves to Eldora as a whole — one PHZM band and one 28°F frost record, read across 3K 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 Eldora Average
Eldora Average
- ●USDA Zones 5b, averaged across Eldora
- ●One soil character for all of Eldora
- ●Frost dates read at Eldora's scale: May 26 to Sep 26
YOUR Parcel
- ✓Your exact zone, not Eldora's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Eldora
Pull a site-specific report for your exact address in Eldora, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Eldora averages can't show:
We read public map data around Eldora — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Eldora average
How we know this about Eldora
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 Eldora’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 Eldora
When does frost risk typically end in Eldora?
The last hard freeze (28°F) in Eldora typically lands around May 26, 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 16.
When is the first frost in Eldora?
The first hard freeze (28°F) in Eldora typically arrives around Sep 26, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 12, so the watching starts about Aug 27 — about 123 days after the spring freeze cleared.
How long is the growing season in Eldora?
Measured between 28°F hard freezes, Eldora sees about 123 frost-free days — roughly May 26 through Sep 26, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 16 to Sep 12, about 88 days.
Is the soil safe to grow vegetables in Eldora?
The federal record around Eldora runs heavier than most — 209 documented sites, mostly Mining entries (128), the nearest Nitrate record about 0.5 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 Eldora?
With about 123 frost-free days between hard freezes, Eldora 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 151 to 179 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 26 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Eldora's scale — its 5b band and its 123-day season. Your yard writes its own version of Eldora'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 Eldora’s own scale
6 of the readings below were taken at Eldora's own scale — its own ~123-day season between 28°F freezes, the 2,660 acres it covers and 209 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Eldora's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Eldora's own 28°F hard-freeze dates, about May 26 and Sep 26 and the ~123-day span between themNOAA 1991–2020 Climate Normals
- 209 documented contamination sites on the federal record near Eldora, the closest Nitrate record about 0.5 miles out from the town centreFederal environmental registers
- Eldora's boundary and the 2,660 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~123-day seasonGrowable Ground crop-matching engine
- The ecoregion at Eldora's own centroid, the Southern RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Eldora's 2,660 acres read through its county's SSURGO summaryfrom Boulder County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Boulder 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 Boulder County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Eldora's 2,660 acreswhy one lot differs from the next →
- Which side of Eldora you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 2,660 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.5 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 Eldora-wide figureread your own land →