Bonanza, Colorado, sits in USDA hardiness zone 5b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Among the crops suited to this profile: cabbage, cranberry, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Bonanza, 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 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 — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Bonanza — the short answer
Bonanza, Colorado: USDA zone 5b, about 121 days between hard freezes, across 280 acres of town.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~121
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 280 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's average, not your lot's — a low corner or a tree line moves it. Against Bonanza's 121-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Bonanza
Each reading below is measured for Bonanza itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredBonanza runs about 121 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 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 is in
Bonanza sits in the Southern Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Bonanza's own centroid rather than borrowed from Saguache County.
What Grows in Bonanza
Every plant below cleared Bonanza's own zone 5b and its 121-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Bonanza?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 29; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 25 — 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 Bonanza
Closest first, within ~10 miles of Bonanza. Listing isn't leaking, and distance isn't exposure.
- National Mineral MillMining · 650 ft
- Bonanza - Kerber Creek DistrictMining · 700 ft
- WarwickMining · 800 ft
- Wheel of FortuneMining · 800 ft
- Wide Awake MineMining · 1100 ft
- Wheel Fo Fortune MineMining · 1200 ft
- Liberty MineMining · 1300 ft
- Mariposa AditMining · 1400 ft
- Saint Joseph MineMining · 1400 ft
- Glennbrook MineMining · 1400 ft
- St. Joe MineMining · 1900 ft
- Oregon MineMining · 1900 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Bonanza'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.
Total Sites
179
within ~10 miles of Bonanza
Risk Level
High
Highest-severity
2 Superfund sites (none NPL-listed)
Severity Distribution
within ~10 miles of Bonanza
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Bonanza, Mining runs higher than the national average — 176 sites within ~10 miles of Bonanza. 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.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Bonanza
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 average
Your land is one point inside Bonanza
Everything above resolves to Bonanza as a whole — one PHZM band and one 28°F frost record, read across 280 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 Average
Bonanza Average
- ●USDA Zones 5b, averaged across Bonanza
- ●One soil character for all of Bonanza
- ●Frost dates read at Bonanza's scale: May 27 to Sep 25
YOUR Parcel
- ✓Your exact zone, not Bonanza's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Bonanza
Pull a site-specific report for your exact address in Bonanza, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Bonanza averages can't show:
We read public map data around Bonanza — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Bonanza average
How we know this about Bonanza
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’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
When does frost risk typically end in Bonanza?
The last hard freeze (28°F) in Bonanza typically lands around May 27, 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 17.
When is the first frost in Bonanza?
The first hard freeze (28°F) in Bonanza typically arrives around Sep 25, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 11, so the watching starts about Aug 26 — about 121 days after the spring freeze cleared.
How long is the growing season in Bonanza?
Measured between 28°F hard freezes, Bonanza sees about 121 frost-free days — roughly May 27 through Sep 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 17 to Sep 11, about 86 days.
Is the soil safe to grow vegetables in Bonanza?
The federal record around Bonanza runs heavier than most — 179 documented sites, mostly Mining entries (176), the nearest Mining record about 0.1 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?
With about 121 frost-free days between hard freezes, Bonanza 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 149 to 177 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 27 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Bonanza's scale — its 5b band and its 121-day season. Your yard writes its own version of Bonanza'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’s own scale
6 of the readings below were taken at Bonanza's own scale — its own ~121-day season between 28°F freezes, the 280 acres it covers and 179 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Bonanza's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Bonanza's own 28°F hard-freeze dates, about May 27 and Sep 25 and the ~121-day span between themNOAA 1991–2020 Climate Normals
- 179 documented contamination sites on the federal record near Bonanza, the closest Mining record about 0.1 miles out from the town centreFederal environmental registers
- Bonanza's boundary and the 280 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~121-day seasonGrowable Ground crop-matching engine
- The ecoregion at Bonanza's own centroid, the Southern RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Bonanza's 280 acres read through its county's SSURGO summaryfrom Saguache County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Saguache 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 Saguache County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Bonanza's 280 acreswhy one lot differs from the next →
- Which side of Bonanza you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 280 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Mining record about 0.1 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-wide figureread your own land →
More in Colorado
Growing region
Nearby growing guides