Generally — Most Areas
ashwagandha (zones 8-12) suits most of Oregon (5a-10a) — zones 8-10 are in range, and the rest of the state is the exception.
Ashwagandha in Oregon — the short answer
Ashwagandha in Oregon: hardy in zones 8–12, full sun, against a state median of ~213 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
- Oregon zones
- 5a-10a
- USDA PHZM 2023
- Frost window
- Feb 25 - Apr 26 – Oct 19 - Nov 26
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 86 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.
Oregon spans zones 5a-10a, 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.
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Oregon is not one climate
Oregon’s winter-low ladder runs across 36 counties, from zone 6 in Klamath County to zone 9.5 in Curry County. That is 35°F between the two counties’ average coldest night — the difference between ashwagandha overwintering in the ground and coming under cover.
The middle half of 36 counties runs 6.5–8.5 zones, with a median of 7.5 zones — a 3.5-zone span end to end.
Measured across 36 Oregon 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 in Oregon Fits Best
Ashwagandha is rated for zones 8–12 — a cold floor USDA puts at 10 to 20°F. Against Oregon’s 36 counties that band holds in 18 of them, and the line runs at Clackamas County (zone 8a), the coldest county still inside it.
Inside zones 8–12
18 counties
- Josephine County · zone 8a
- Marion County · zone 8a
- Benton County · zone 8b
3 of 18 shown
Below the zone 8 floor
18 counties
- Klamath County · zone 6a
- Baker County · zone 6b
- Crook County · zone 6b
3 of 18 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.
Even within Oregon's zones 5a-10a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for ashwagandha (USDA PHZM 2023):
Zone Comparison
Ashwagandha Needs
- USDA Zones: 8-12
- Frost-Free Days: 150+
- Sun: Full Sun
- Mature size: 3 ft tall
- Drought tolerance: High
Oregon Has
- USDA Zones: 5a-10a
- Last Hard Freeze (28°F): Feb 25 - Apr 26
- First Hard Freeze (28°F): Oct 19 - Nov 26
- Annual Rainfall: 8-90 inches
- Common Soils: Volcanic, Silt loam (Willamette), Sandy loam
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 Oregon
The frost window
Across Oregon, the last spring hard freeze (28°F) clears between Feb 25 and Apr 26, and the first fall hard freeze lands between Oct 19 and Nov 26 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 176-day window you can count on — up to 274 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 Oregon's late-side last freeze of Apr 26 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Winter standing
Oregon runs as cold as USDA zone 5, 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 Oregon; check its hardiness range against that before treating it as long-lived ground.
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 survives winter in part of Oregon, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Ashwagandha wants 150+ frost-free days; a typical Oregon site sees ~213 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Ashwagandha needs ~2000 GDD (base 50°F) to ripen. The state median runs ~1666 GDD (from PRISM 1991-2020 climate normals), so Oregon'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 Oregon's volcanic and silt loam (willamette) — 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 Oregon soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Oregon site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
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. Oregon 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 Oregon’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 Oregon — and how to grow with it.
We checked the federal record across Oregon — 21,752 documented sites across 8 of the 9 source types we track.
The most significant on record: 260 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Oregon 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 Oregon
Severity Distribution
across Oregon
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Oregon, Mining runs higher than the national average — 3,562 sites across Oregon. 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.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What Else to Consider for Ashwagandha in Oregon
Zone compatibility tells you about winter cold survival — but Oregon growers also need to think about:
West side: excessive rain and overcast skies reduce sun for warm-season crops
East side: arid conditions (8-15 inches rainfall) require irrigation
Slug pressure is extreme in western Oregon
Mountain areas have very short seasons (60-90 frost-free days)
What to actually do about these — and the constraints that apply to every Oregon grower, not just ashwagandha — is covered on the Oregon growing guide.
Timing shifts within Oregon
Ashwagandha needs about 150 days of frost-free season to complete its cycle. 33 of Oregon’s 36 counties give it that outright. The tightest that does is Baker County at 150 frost-free days — 0 to spare. Below that line you are transplanting or extending the season, not direct-sowing.
Across Oregon’s 36 counties the frost-free season runs from 86 days in Klamath County to 308 days in Lincoln County — a spread of 222 days, which is why a single statewide planting date misleads. The median Oregon county sees 213 frost-free days, leaving ashwagandha about 63 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 Oregon's frost window — roughly 213 days, opening after the last 28°F freeze (Feb 25 - Apr 26) and closing at the first (Oct 19 - Nov 26), per NOAA Regional Climate Centers ACIS, 1991-2020.
Oregon Cooperative Extension
For Oregon-specific cultivar recommendations, planting calendars, and pest pressure for ashwagandha, the canonical source is OSU Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Ashwagandha in Oregon
When can I plant Ashwagandha in Oregon?
Oregon's last spring hard freeze (28°F) clears between Feb 25 and Apr 26, and the first fall hard freeze lands between Oct 19 and Nov 26 (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 Oregon 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 Oregon?
Oregon spans USDA hardiness zones 5a-10a (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 Oregon site have?
A typical Oregon site sees ~213 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.
How should I amend the soil for Ashwagandha in Oregon?
Ashwagandha prefers pH 6.5-8.5 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Oregon 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 Oregon?
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 Oregon
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 Oregon ashwagandha averages can't show:
We read public map data around Oregon — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Oregon ashwagandha average
Explore More
Growing guides for ashwagandha
Explore Oregon county by county
Oregon carries 36 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 Oregon 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 Oregon
Oregon has a growing page for 1,038 plants — a rotating sample of the rest of the shelf.
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