Unlikely — Zone Mismatch
potato yam (zones 9-12) does not overlap with Virginia's zone range (5b-8b). Growing outdoors is unlikely without significant protection.
One zone short — what would close it
Potato Yam is hardy to zone 9, and the warmest ground in Virginia is zone 8 — 1 zone short. Planted in open ground it will not survive a Virginia winter. To grow it here, grow potato yam in a container and move it under cover for the coldest weeks, or give it a greenhouse.
Season extension and overwintering under cover both work at this margin. How to buy the weeks →
Zone math from 9-12 (plant) against 6-8 (Virginia). Lift modeled by crop_engine Sprint 20B effective_zone_modifier (+2 zones) via api/fast_sections.py Unlock Engine v2.
Your yard isn't the whole zone.
Virginia spans zones 5b-8b, 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 potato yam against your parcel's actual hardiness, soil, and sun.
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Zone Comparison
Potato Yam Needs
- USDA Zones: 9-12
- Frost-Free Days: 90+
- Sun: Full Sun
- Picking window: ~30 days of harvest
Virginia Has
- USDA Zones: 5b-8b
- Last Hard Freeze (28°F): Mar 22 - Apr 2
- First Hard Freeze (28°F): Nov 2 - Nov 17
- Annual Rainfall: 36-50 inches
- Common Soils: Red clay (Piedmont), Silt loam, Sandy loam (Tidewater)
Plant Zone Range (zones 9-12)
Preferred Soil pH
Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Potato Yam in Virginia
The frost window
Across Virginia, the last spring hard freeze (28°F) clears between Mar 22 and Apr 2, and the first fall hard freeze lands between Nov 2 and Nov 17 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 214-day window you can count on — up to 240 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.
Winter standing
Virginia runs as cold as USDA zone 5, and no sourced winter-hardiness floor is on record for potato yam, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether potato yam is a permanent planting or a replant-every-spring crop for you turns on your own zone within Virginia; check its hardiness range against that before treating it as long-lived ground.
Timing tuned to sub-state frost dates — Highland County, not the statewide average.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: USDA PLANTS Database. 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 potato yam does not survive a Virginia 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 Virginia under protection.
Frost-free days
Potato Yam wants 90+ frost-free days; a typical Virginia site sees ~224 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
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
Potato Yam likes near-neutral soil (pH 5.3-8). That's the common-ground band across Virginia's red clay (piedmont) and silt loam — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6 and 6.7 — worth knowing before you decide whether a Virginia soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Virginia site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
Virginia's soils run mostly fine sandy loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Potato Yam needs about 59 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 potato yam performs.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH and drainage requirements from USDA PLANTS Database. Virginia soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Potato Yam in Virginia — Quick Answer
- Verdict: Unlikely — Zone Mismatch
- Plant Zones: 9-12 (USDA PLANTS Database)
- State Zones: 5b-8b (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Mar 22 - Apr 2 to Nov 2 - Nov 17 (NOAA Regional Climate Centers ACIS, 1991-2020)
What Else to Consider for Potato Yam in Virginia
Zone compatibility tells you about winter cold survival — but Virginia growers also need to think about:
Heavy Piedmont red clay requires amendment
Humidity and heat in summer promote disease
Deer pressure is heavy in suburban and rural areas
Growing potato yam here specifically
Virginia's soils run mostly fine sandy loam (Ultisols), and whether that suits potato yam's pH 5.3–8.0 preference comes down to your exact parcel, not the statewide picture.
Pull your parcel's SSURGO map unit, test pH, and amend toward potato yam's 5.3–8.0 target before planting. How to handle it →
What to actually do about these — and the constraints that apply to every Virginia grower, not just potato yam — is covered on the Virginia growing guide.
Timing shifts within Virginia
Virginia isn't one climate. In Highland County, the last hard freeze (28°F) holds until about Apr 27 — roughly 30 days later than the recorded state median — so plant potato yam to your county's window, not the statewide date.
Potato Yam needs about 90 days of frost-free season to complete its cycle. Even Highland County — Virginia’s shortest season at 176 frost-free days — clears that by 86 days, so season length isn’t the constraint anywhere in Virginia. What varies is your own parcel.
Across Virginia’s 133 counties the frost-free season runs from 176 days in Highland County to 289 days in Hampton County — a spread of 113 days, which is why a single statewide planting date misleads. The median Virginia county sees 224 frost-free days, leaving potato yam about 134 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"). Potato Yam's 90-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
Potato Yam draws native bees (low value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, potato yam can only work that bloom inside Virginia's frost window — roughly 224 days, opening after the last 28°F freeze (Mar 22 - Apr 2) and closing at the first (Nov 2 - Nov 17), per NOAA Regional Climate Centers ACIS, 1991-2020.
Good to Know Before You Plant Potato Yam
Potato Yam is listed as toxic to dogs, cats (all) at a moderate level (Cornell). Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear.
Virginia Cooperative Extension
For Virginia-specific cultivar recommendations, planting calendars, and pest pressure for potato yam, the canonical source is Virginia Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Potato Yam native to Virginia?
No — the USDA PLANTS Database lists Potato Yam as introduced rather than native in the Lower 48, so it is not part of Virginia's native flora. It grows here as a garden plant; pairing it with a few Virginia natives keeps local pollinators fed too.
Looking for plants that belong here? The Virginia growing guide lists USDA-documented natives for the state.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Potato Yam in Virginia
When can I plant Potato Yam in Virginia?
Virginia's last spring hard freeze (28°F) clears between Mar 22 and Apr 2, and the first fall hard freeze lands between Nov 2 and Nov 17 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Potato Yam, so this page does not state whether it overwinters in Virginia 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 Potato Yam grown in across Virginia?
Virginia spans USDA hardiness zones 5b-8b (USDA ARS PHZM 2023). Potato Yam carries a range of zones 9-12, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Virginia site have?
A typical Virginia site sees ~224 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Potato Yam needs 90+ 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 Highland, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Potato Yam native to Virginia?
No — the USDA PLANTS Database lists Potato Yam as introduced rather than native in the Lower 48, so it is not part of Virginia's native flora. It grows here as a garden plant; pairing it with a few Virginia natives keeps local pollinators fed too.
How should I amend the soil for Potato Yam in Virginia?
Potato Yam prefers pH 5.3-8 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Virginia soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Potato Yam actually grow on my specific land in Virginia?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores potato yam 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 Virginia
State-level data is a sketch. Your Growable Ground report scores potato yam against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Virginia potato yam averages can't show:
We read public map data around Virginia — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Virginia potato yam average
Explore More
Growing guides for potato yam
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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