Wyoming spans USDA hardiness zones 3a-5b, with a growing season of about 170 frost-free days — a working season long enough for the classics, short enough that timing around frost stays part of the craft.
Those zone numbers rest on 6-20 inches of annual rainfall, a median of roughly 2,700 growing-degree days (base 50°F), and about 1,650 winter chill hours for tree fruit — the measurements that do the deciding. The prevailing soils — sandy loam, clay, alkaline, and volcanic ash — differ most in how they drain, which is exactly where crop success is usually decided. Among the crops suited to this profile: potato, indian paintbrush, cottonwood, and rhubarb. The site-level story — soil, sun, drainage — decides the rest.
Grounded inUSDA PHZM 2023•NOAA Climate Normals•USDA NRCS SSURGO•GDD aggregate (Cornell CALS)•Chill-hour aggregate (MSU Extension)•EPA FRS•USDA PLANTS•Growable Ground suitability scoring
Wyoming spans zones 3a-5b, but your yard sits in exactly one — and slope, tree cover, and low spots nudge it further. 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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Distinct growing regions within Wyoming — each has its own zones, soils, and signature crops.
USDA Zones
3a-5b
USDA PHZM 2023
Last Frost
May 10 - Jun 15
NOAA 30-yr Normals
First Frost
Aug 25 - Sep 25
NOAA 30-yr Normals
Annual Rainfall
6-20 inches
NOAA Climate Normals
Zone maps are averages across Wyoming. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
The soil types that dominate Wyoming — how each drains decides more about crop success than almost anything else. Tap any soil to learn what it is and how to work with it.
Drainage
Fast. The sand fraction opens the soil up, so water moves through the root zone quickly and the surface rarely stays soggy. The trade is that nutrients ride out with the water.
What thrives
Root crops love it — carrots, potatoes, radishes, and onions size up cleanly in ground they can push through. Melons, sweet potatoes, asparagus, and most herbs appreciate the warmth and the drainage.
Drainage
Slow. Water enters clay reluctantly and leaves it the same way, so wet springs keep it cold and unworkable longer than lighter soils.
What thrives
Once established, heavy feeders prosper — brassicas, beans, corn, and many fruit trees ride clay’s nutrient supply and summer moisture reserve. Daylilies, roses, and prairie perennials handle it without complaint.
Alkaline soil is defined by pH, not looks — it ranges from sand to clay. The label, not a photo, is the point.
Drainage
Alkalinity is chemistry, not texture — these soils range from fast sands to slow clays. What they share is the high pH, not a drainage habit.
What thrives
A long roster of garden plants is comfortable above pH 7: asparagus, beets, spinach, brassicas, figs, pomegranates, lavender, and most Mediterranean herbs among them.
Drainage
Excellent and unusual: ash soils drain freely yet hold remarkable amounts of plant-available water in their porous structure — the best of both habits.
What thrives
Volcanic regions grow celebrated crops the world over: orchards, berries, vegetables, coffee, and wine grapes all prosper on ash-derived soils.
Soil data: USDA NRCS SSURGO · Soil types explained
Plants well-suited to Wyoming's climate, soils, and growing season — each links to its full growing profile.
Usually not — gardeners here simply switch what goes in the ground as the season moves. Across Wyoming, cool-season planting typically opens about four weeks before the local last hard freeze — county medians put that freeze near Apr 28, with the middle half of counties between Apr 23 and May 6 (NOAA 1991–2020 climate normals). Tender transplants wait two to three weeks past it, and fall planting counts back from first freezes mostly between Oct 10 and Oct 16 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
The plants Wyoming put its name on — cultural emblems, not growing recommendations.
Indian paintbrush
Castilleja linariifolia
Designated 1917.
Plains cottonwood
Populus deltoides monilifera
Designated 1947.
Plants the USDA PLANTS Database documents as native and present in Wyoming — a real per-state range, not just a zone match. Presence is statewide, so a plant may still be uncommon in your specific county; your state’s Cooperative Extension or a native-plant society is the local authority.
US-native plants whose hardiness range overlaps Wyoming’s USDA zones 3a-5b but which USDA PLANTS doesn’t map to a single state range here. Zone overlap is a starting filter, not a range map.
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.
Safe to Grow Here?What the federal record shows across Wyoming — and how to grow with it.
We checked the federal record across Wyoming — 10,910 documented sites across 8 of the 9 source types we track.
The most significant on record: 64 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Wyoming carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Severity Distribution
across Wyoming
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Wyoming, Nitrate runs higher than the national average — 4,750 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).
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
State averages sketch the shape. Your soil, sun exposure, drainage, and microclimate decide what actually takes. Pull a site-specific report for your exact parcel.
Enter your address. We read your soil, sun, drainage, and frost dates, then score 1,112 plants against the real conditions on your land.
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
Wyoming spans USDA hardiness zones 3a-5b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
Usually not — gardeners here simply switch what goes in the ground as the season moves. Across Wyoming, cool-season planting typically opens about four weeks before the local last hard freeze — county medians put that freeze near Apr 28, with the middle half of counties between Apr 23 and May 6 (NOAA 1991–2020 climate normals). Tender transplants wait two to three weeks past it, and fall planting counts back from first freezes mostly between Oct 10 and Oct 16 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
Across Wyoming, the middle half of counties see their last hard freeze (28°F) between about Apr 23 and May 6, with a county median near Apr 28 (NOAA 1991–2020 climate normals). 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.
Measured between 28°F hard freezes, growing seasons across Wyoming's counties mostly run about 157 to 176 days, with a county median near 169 (NOAA 1991–2020 climate normals). Tender crops get a somewhat shorter practical window, since lighter frosts reach a few weeks past the hard-freeze dates on both ends.
Wyoming's zones 3a-5b 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.
Officially, Wyoming spans USDA zones 3a-5b (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.
The federal record across Wyoming runs heavier than most — 10,910 documented sites — 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.
Start with three facts. Wyoming spans USDA zones 3a-5b, which sets what survives winter; last hard freezes range from about Apr 23 to May 6 across its counties (NOAA 1991–2020 climate normals); and 10,910 documented sites sit on the federal record here, so a soil test before food beds is the smart first step. From there, matching plants to your actual soil and sun is the fun part.
Everything on this page is a Wyoming 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.
Explore growing conditions by city or town in Wyoming.
