Dubois, Wyoming, sits in USDA hardiness zones 5a-6b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Crops well matched to these conditions include potato, indian paintbrush, cottonwood, and rhubarb — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Dubois, 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 Dubois lot. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Quick Facts
USDA Zones
5a-6b
Last Hard Freeze (28°F)
May 20
Town normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Sep 25
Town normal — light frosts arrive a few weeks earlier
Town Area
2K acres
Hardiness Zone Range
Zone maps are averages across Dubois. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil varies lot by lot — soil types explained.
What Grows in Dubois
Plants matched to Dubois's USDA zones 5a-6b — each links to its full growing profile.



Is it too late to plant in Dubois?
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 22; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 20 (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. In a season this compact, fast finishers and cold-hardy greens do the late work, and garlic tucked in before the freeze repays you next summer.

Growing Challenges in Wyoming
What an experienced grower plans around here — each one has a move.

Extremely short growing season (60-90 frost-free days)
At 60-90 frost-free days, a greenhouse or high tunnel isn't optional equipment — it's where the season actually happens.

Very low rainfall requires irrigation
Drip irrigation under mulch makes scarce water go the distance — build the system before the first bed.

Persistent high winds desiccate and damage plants
Windbreaks first, plants second — a sheltered bed loses a fraction of the moisture an exposed one does.
For cultivar selection, pest pressure, and planting-time guidance specific to Wyoming, the University of Wyoming Extension is the authoritative local source.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Sources Checked
within ~10 miles of Dubois
Severity Distribution
within ~10 miles of Dubois
Highest-Severity Sites

A note from Gnorman
What an experienced grower watches for around here
In and around Dubois, Nitrate runs higher than the national average — 24 sites nearby. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Dubois
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Dubois Average
- ●USDA Zones 5a-6b
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Dubois
Pull a site-specific report for your exact address in Dubois, Wyoming — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Dubois, Wyoming
- USDA Hardiness Zones: 5a-6b (USDA PHZM 2023)
- Last Hard Freeze (28°F): May 20 (town normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Sep 25 (town normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~128 (town normal, NOAA 1991–2020 Climate Normals)
- Land Area: 2K acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. Boundaries: US Census TIGER/Line 2025.
Frequently Asked Questions
What hardiness zone is Dubois, Wyoming?
Dubois sits in USDA hardiness zones 5a-6b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
Is it too late to plant in Dubois?
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 22; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 20 (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. In a season this compact, fast finishers and cold-hardy greens do the late work, and garlic tucked in before the freeze repays you next summer.
When does frost risk typically end in Dubois?
The last hard freeze (28°F) in Dubois typically lands around May 20, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.
When is the first frost in Dubois?
The first hard freeze (28°F) in Dubois typically arrives around Sep 25, per NOAA 1991–2020 climate normals — the point most tender summer crops finish. Lighter frosts usually reach a couple of weeks earlier, so watch the forecast from late summer on and harvest or cover tender plants before the first cold night.
What vegetables grow in Dubois?
Dubois's zones 5a-6b support a wide range — strong performers include Potato, Indian Paintbrush, Cottonwood, Rhubarb, and Chokecherry. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Dubois, really?
Officially, Dubois sits in USDA zones 5a-6b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Dubois?
The federal record around Dubois shows 51 documented sites — 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 Dubois?
With about 128 frost-free days between hard freezes, Dubois rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder, cold frames and low tunnels more, and quick-maturing varieties make the arithmetic work. Starting transplants indoors ahead of the May 20 hard-freeze normal stretches the season without touching the calendar.
Everything on this page is a Dubois average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.
