Unlikely — Zone Mismatch
ashwagandha (zones 8-12) does not overlap with Wyoming's zone range (3b-6a). Growing outdoors is unlikely without significant protection.
2 zones short — what would close it
Ashwagandha is hardy to zone 8, and the warmest ground in Wyoming is zone 6 — 2 zones short. Planted in open ground it will not survive a Wyoming winter. To grow it here, grow ashwagandha in an earth-sheltered greenhouse — its modeled 2.5-zone lift covers this gap.
An earth-sheltered greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 8-12 (plant) against 3-6 (Wyoming). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['earth_sheltered'] (+2.5 zones) via api/fast_sections.py Unlock Engine v2.
Ashwagandha in Wyoming — the short answer
Ashwagandha in Wyoming: hardy in zones 8–12, full sun, against a state median of ~151 frost-free days.
- Plant zones
- 8-12
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Wyoming zones
- 3b-6a
- USDA PHZM 2023
- Frost window
- May 4 - May 13 – Sep 30 - Oct 7
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 79 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
- Days to maturity
- 150 days
- Growable Ground Plant Database
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.
Your yard isn't the whole zone.
Wyoming spans zones 3b-6a, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score ashwagandha against your parcel's actual hardiness, soil, and sun.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Wyoming is not one climate
Wyoming’s winter-low ladder runs across 23 counties, from zone 4.5 in Albany County to zone 5.5 in Uinta County. That is 10°F between the two counties’ average coldest night — the difference between ashwagandha overwintering in the ground and coming under cover.
The middle half of 23 counties runs 4.5–5 zones, with a median of 5 zones — a 1-zone span end to end.
Measured across 23 Wyoming counties. USDA PHZM 2023, per county. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.
Where Ashwagandha Stands in Wyoming
Ashwagandha is rated for zones 8–12 — a cold floor USDA puts at 10 to 20°F. No Wyoming county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Wyoming winters, not about ashwagandha.
Below the zone 8 floor
23 counties
- Albany County · zone 4b
- Big Horn County · zone 4b
- Hot Springs County · zone 4b
3 of 23 shown
Winter cold is the limit here — the same plant works in a container that comes under cover.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.
Zone Comparison
Ashwagandha Needs
- USDA Zones: 8-12
- Frost-Free Days: 150+
- Sun: Full Sun
- Mature size: 3 ft tall
- Drought tolerance: High
Wyoming Has
- USDA Zones: 3b-6a
- Last Hard Freeze (28°F): May 4 - May 13
- First Hard Freeze (28°F): Sep 30 - Oct 7
- Annual Rainfall: 6-20 inches
- Common Soils: Sandy loam, Clay, Alkaline
Plant Zone Range (zones 8-12)
Preferred Soil pH
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Ashwagandha in Wyoming
The frost window
Across Wyoming, the last spring hard freeze (28°F) clears between May 4 and May 13, and the first fall hard freeze lands between Sep 30 and Oct 7 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 140-day window you can count on — up to 156 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.
When to start the seed
Those dates are when ashwagandha goes out, not when it starts. It is sown under cover about 8 weeks ahead, so counting back from Wyoming's late-side last freeze of May 13 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Winter standing
Wyoming runs as cold as USDA zone 3, and no sourced winter-hardiness floor is on record for ashwagandha, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether ashwagandha is a permanent planting or a replant-every-spring crop for you turns on your own zone within Wyoming; check its hardiness range against that before treating it as long-lived ground.
Timing tuned to sub-state frost dates — Teton County, not the statewide average.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.
Growing Season Fit
The zone check says ashwagandha does not survive a Wyoming winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on Wyoming under protection.
Frost-free days
Ashwagandha wants 150+ frost-free days; a typical Wyoming site sees ~151 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves a tight window — use transplants and pick early-maturing cultivars.
Growing degree days
Ashwagandha needs ~2000 GDD (base 50°F) to ripen. The state median runs ~1866 GDD (from PRISM 1991-2020 climate normals), so Wyoming's typical season runs short on heat — pick a south-facing site and consider season extension.
GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.
Soil + Drainage Fit
Ashwagandha likes near-neutral soil (pH 6.5-8.5). That's the common-ground band across Wyoming's sandy loam and clay — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 7.5 and 8 — worth knowing before you decide whether a Wyoming soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Wyoming site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
Wyoming's soils run mostly loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Ashwagandha needs about 19 inches of workable depth, so it is that horizon — not the surface — you are testing for. That map unit, not the state average, decides how ashwagandha performs.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Wyoming soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Before you plant ashwagandha for food
Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before ashwagandha goes in. What follows is Wyoming’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.
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.
Sources Checked
across Wyoming
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 across Wyoming. 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.
What Else to Consider for Ashwagandha in Wyoming
Zone compatibility tells you about winter cold survival — but Wyoming growers also need to think about:
Extremely short growing season (60-90 frost-free days)
Very low rainfall requires irrigation
Persistent high winds desiccate and damage plants
Growing ashwagandha here specifically
At ~150 days to harvest, ashwagandha barely fits Wyoming's ~151 frost-free days — there's little slack if spring runs cold.
Give ashwagandha an indoor head start and a row cover in fall to beat the first freeze. How to handle it →
What to actually do about these — and the constraints that apply to every Wyoming grower, not just ashwagandha — is covered on the Wyoming growing guide.
Timing shifts within Wyoming
Wyoming isn't one climate. In Teton County, the last hard freeze (28°F) holds until about Jun 16 — roughly 41 days later than the recorded state median — so plant ashwagandha to your county's window, not the statewide date.
Ashwagandha needs about 150 days of frost-free season to complete its cycle. 14 of Wyoming’s 23 counties give it that outright. The tightest that does is Natrona County at 150 frost-free days — 0 to spare. Below that line you are transplanting or extending the season, not direct-sowing.
Across Wyoming’s 23 counties the frost-free season runs from 79 days in Teton County to 166 days in Big Horn County — a spread of 87 days, which is why a single statewide planting date misleads. The median Wyoming county sees 151 frost-free days, leaving ashwagandha about 1 days of slack on a typical parcel — room for a second sowing where the season runs long.
County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Ashwagandha's 150-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Pollinator + Wildlife Value
Ashwagandha draws honeybees (low value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, ashwagandha can only work that bloom inside Wyoming's frost window — roughly 151 days, opening after the last 28°F freeze (May 4 - May 13) and closing at the first (Sep 30 - Oct 7), per NOAA Regional Climate Centers ACIS, 1991-2020.
Good to Know Before You Plant Ashwagandha
Ashwagandha is listed as toxic to dogs, cats (all) at a mild level (Pet Poison Helpline). Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear.
Recommended Ashwagandha Varieties for Wyoming
Wyoming publishes no state variety trial for ashwagandha, so we won't invent a "best for Wyoming" list. Choose types rated to your USDA hardiness zone (3b-6a), and confirm winter survival and drainage against your own parcel.
Wyoming Cooperative Extension
For Wyoming-specific cultivar recommendations, planting calendars, and pest pressure for ashwagandha, the canonical source is University of Wyoming Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Ashwagandha in Wyoming
When can I plant Ashwagandha in Wyoming?
Wyoming's last spring hard freeze (28°F) clears between May 4 and May 13, and the first fall hard freeze lands between Sep 30 and Oct 7 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Ashwagandha, so this page does not state whether it overwinters in Wyoming and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.
What hardiness zone is Ashwagandha grown in across Wyoming?
Wyoming spans USDA hardiness zones 3b-6a (USDA ARS PHZM 2023). Ashwagandha carries a range of zones 8-12, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Wyoming site have?
A typical Wyoming site sees ~151 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Ashwagandha needs 150+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Teton, the freeze-free season runs shorter than the state average, so verify your own county's window.
How should I amend the soil for Ashwagandha in Wyoming?
Ashwagandha prefers pH 6.5-8.5 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Wyoming soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Ashwagandha actually grow on my specific land in Wyoming?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores ashwagandha against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Wyoming
State-level data is a sketch. Your Growable Ground report scores ashwagandha against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Wyoming ashwagandha averages can't show:
We read public map data around Wyoming — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Wyoming ashwagandha average
Explore More
Growing guides for ashwagandha
Explore Wyoming county by county
Wyoming carries 23 counties with their own USDA zone — a sample of the growing pages for ashwagandha there:
Where else ashwagandha grows
Ashwagandha's zone band crosses state lines — these are the states closest to Wyoming in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.
More to grow in Wyoming
Wyoming has a growing page for 806 plants — a rotating sample of the rest of the shelf.
Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →
Cite this dataset
Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643
Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643
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