Bonanza Mountain Estates, Colorado, sits in USDA hardiness zone 5b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
The conditions favor cabbage, cranberry, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Bonanza Mountain Estates, 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 Bonanza Mountain Estates 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 Bonanza Mountain Estates — soil, climate, flood, and parcel records. How we handle your address.
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Bonanza Mountain Estates — the short answer
Bonanza Mountain Estates, Colorado: USDA zone 5b, about 136 days between hard freezes, across 108 acres of town.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~136
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 108 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 Bonanza Mountain Estates's average, not your lot's — a low corner or a tree line moves it. Against Bonanza Mountain Estates's 136-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Bonanza Mountain Estates
Each reading below is measured for Bonanza Mountain Estates itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredBonanza Mountain Estates runs about 136 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
MeasuredBonanza Mountain Estates 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 Bonanza Mountain Estates is in
Bonanza Mountain Estates sits in the Southern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Bonanza Mountain Estates's own centroid rather than borrowed from Boulder County.
What Grows in Bonanza Mountain Estates
Every plant below cleared Bonanza Mountain Estates's own zone 5b and its 136-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Bonanza Mountain Estates?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Apr 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 16 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 29 — 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 Bonanza Mountain Estates
Closest first, within ~10 miles of Bonanza Mountain Estates. Listing isn't leaking, and distance isn't exposure.
- SC00107208CAAC SITE 013Nitrate · 1100 ft
- Stevens Camp TunnelsMining · 0.5 mi
- SC00107208BBBC SITE 017Nitrate · 0.5 mi
- SC00107207DDCB SITE 014Nitrate · 0.5 mi
- SC00107205CBCD SITE 018Nitrate · 0.9 mi
- CDOT NederlandUnderground Storage Tanks · 1.1 mi
- Boulder County Road Maintenance FacilityUnderground Storage Tanks · 1.2 mi
- Lucky Strike, Last NickelMining · 1.3 mi
- Boulder Road Dist 3Underground Storage Tanks · 1.4 mi
- SC00107204DCDC SITE 016Nitrate · 1.4 mi
- SC00107205BBCC SITE C23Nitrate · 1.4 mi
- UNIVERSITY OF CO BOULDER-MT RESEARCH CNTBrownfields · 1.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Bonanza Mountain Estates'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 Bonanza Mountain Estates.
Total Sites
278
within ~10 miles of Bonanza Mountain Estates
Risk Level
High
Highest-severity
7 Superfund sites
Sources Checked
within ~10 miles of Bonanza Mountain Estates
Severity Distribution
within ~10 miles of Bonanza Mountain Estates
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Bonanza Mountain Estates, two things run higher than the national average within ~10 miles of Bonanza Mountain Estates — Mining (145 sites) and Superfund (7 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 Bonanza Mountain Estates
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 Bonanza Mountain Estates average
Your land is one point inside Bonanza Mountain Estates
Everything above resolves to Bonanza Mountain Estates as a whole — one PHZM band and one 28°F frost record, read across 108 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 Bonanza Mountain Estates Average
Bonanza Mountain Estates Average
- ●USDA Zones 5b, averaged across Bonanza Mountain Estates
- ●One soil character for all of Bonanza Mountain Estates
- ●Frost dates read at Bonanza Mountain Estates's scale: May 16 to Sep 29
YOUR Parcel
- ✓Your exact zone, not Bonanza Mountain Estates's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Bonanza Mountain Estates
Pull a site-specific report for your exact address in Bonanza Mountain Estates, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Bonanza Mountain Estates averages can't show:
We read public map data around Bonanza Mountain Estates — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Bonanza Mountain Estates average
How we know this about Bonanza Mountain Estates
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 Bonanza Mountain Estates’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 Bonanza Mountain Estates
When does frost risk typically end in Bonanza Mountain Estates?
The last hard freeze (28°F) in Bonanza Mountain Estates typically lands around May 16, 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 6.
When is the first frost in Bonanza Mountain Estates?
The first hard freeze (28°F) in Bonanza Mountain Estates typically arrives around Sep 29, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 15, so the watching starts about Aug 30 — about 136 days after the spring freeze cleared.
How long is the growing season in Bonanza Mountain Estates?
Measured between 28°F hard freezes, Bonanza Mountain Estates sees about 136 frost-free days — roughly May 16 through Sep 29, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 6 to Sep 15, about 101 days.
Is the soil safe to grow vegetables in Bonanza Mountain Estates?
The federal record around Bonanza Mountain Estates runs heavier than most — 278 documented sites, mostly Mining entries (145), the nearest Nitrate 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 Bonanza Mountain Estates?
With about 136 frost-free days between hard freezes, Bonanza Mountain Estates 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 164 to 192 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 16 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Bonanza Mountain Estates's scale — its 5b band and its 136-day season. Your yard writes its own version of Bonanza Mountain Estates'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 Bonanza Mountain Estates’s own scale
6 of the readings below were taken at Bonanza Mountain Estates's own scale — its own ~136-day season between 28°F freezes, the 108 acres it covers and 278 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Bonanza Mountain Estates's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Bonanza Mountain Estates's own 28°F hard-freeze dates, about May 16 and Sep 29 and the ~136-day span between themNOAA 1991–2020 Climate Normals
- 278 documented contamination sites on the federal record near Bonanza Mountain Estates, the closest Nitrate record about 0.2 miles out from the town centreFederal environmental registers
- Bonanza Mountain Estates's boundary and the 108 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~136-day seasonGrowable Ground crop-matching engine
- The ecoregion at Bonanza Mountain Estates's own centroid, the Southern RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Bonanza Mountain Estates's 108 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 Bonanza Mountain Estates's 108 acreswhy one lot differs from the next →
- Which side of Bonanza Mountain Estates you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 108 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.2 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 Bonanza Mountain Estates-wide figureread your own land →
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