Unlikely — Zone Mismatch
potato yam (zones 9-12) does not overlap with Michigan's zone range (4a-7a). Growing outdoors is unlikely without significant protection.
2 zones short — what would close it
Potato Yam is hardy to zone 9, and the warmest ground in Michigan is zone 7 — 2 zones short. Planted in open ground it will not survive a Michigan winter. To grow it here, grow potato yam 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 9-12 (plant) against 4-7 (Michigan). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['earth_sheltered'] (+2.5 zones) via api/fast_sections.py Unlock Engine v2.
Potato Yam in Michigan — the short answer
Potato Yam in Michigan: hardy in zones 9–12, full sun.
- Plant zones
- 9-12
- Not verified
- Michigan zones
- 4a-7a
- USDA PHZM 2023
- Frost window
- Apr 19 - May 8 – Oct 12 - Oct 31
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 126 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
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.
Michigan spans zones 4a-7a, 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.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
No card required · your parcel report in seconds — read in full free for your first 14 days
Michigan is not one climate
Michigan’s winter-low ladder runs across 83 counties, from zone 4 in Gogebic County to zone 7 in Allegan County. That is 30°F between the two counties’ average coldest night — the difference between potato yam overwintering in the ground and coming under cover.
The middle half of 83 counties runs 5–6 zones, with a median of 6 zones — a 3-zone span end to end.
Measured across 83 Michigan 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 Potato Yam Stands in Michigan
Potato Yam is rated for zones 9–12 — a cold floor USDA puts at 20 to 30°F. No Michigan 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 Michigan winters, not about potato yam.
Below the zone 9 floor
83 counties
- Gogebic County · zone 4a
- Iron County · zone 4a
- Baraga County · zone 4b
3 of 83 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
Potato Yam Needs
- USDA Zones: 9-12
- Sun: Full Sun
- Picking window: ~30 days of harvestWe haven't confirmed this against a published source yet.
Michigan Has
- USDA Zones: 4a-7a
- Last Hard Freeze (28°F): Apr 19 - May 8
- First Hard Freeze (28°F): Oct 12 - Oct 31
- Annual Rainfall: 28-38 inches
- Common Soils: Sandy loam, Clay loam, Muck
Plant Zone Range (zones 9-12)
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 Potato Yam in Michigan
The frost window
Across Michigan, the last spring hard freeze (28°F) clears between Apr 19 and May 8, and the first fall hard freeze lands between Oct 12 and Oct 31 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 157-day window you can count on — up to 195 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
Michigan runs as cold as USDA zone 4, 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 Michigan; check its hardiness range against that before treating it as long-lived ground.
Timing tuned to sub-state frost dates — Luce 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.
Soil + Drainage Fit
Potato Yam likes near-neutral soil (pH 5.3-8). That's the common-ground band across Michigan's sandy loam and clay 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 Michigan soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Michigan site is heavier clay or sits in a low spot, a raised bed lifts the roots above wet ground, or work in compost.
Your land, not the state average
SSURGO maps about 29.4% of Michigan as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Potato Yam sits mid-range for drought tolerance, so either extreme can cost you — your soil map unit, not the state average, is the real answer.
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. Michigan soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Before you plant potato yam 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 potato yam goes in. What follows is Michigan’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 Michigan — and how to grow with it.
We checked the federal record across Michigan — 35,666 documented sites across 7 of the 8 source types we track.
The most significant on record: 711 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Michigan 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 of imported, lab-tested soil grow well almost anywhere in the meantime.
Sources Checked
across Michigan
Severity Distribution
across Michigan
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Michigan, Brownfields runs higher than the national average — 3,741 sites across Michigan. That's not a problem with your land — it's information about it.
Brownfields: Brownfield sites are former commercial or industrial properties that EPA’s Brownfields program (ACRES) has assessed or funded cleanup on.
Contact the EPA Brownfields program or the state cleanup agency for this site’s actual assessment/remediation status — ACRES itself does not publish one we can read per site.
Sources: EPA, USGS — 950K documented sites tracked nationwide across 8 federal source types.
What Else to Consider for Potato Yam in Michigan
Zone compatibility tells you about winter cold survival — but Michigan growers also need to think about:
Lake effect weather creates highly localized microclimates
Short northern season (100-120 frost-free days in UP)
Sandy soils in western MI drain too quickly
Growing potato yam here specifically
Potato Yam roots run deep and prefer pH 5.3–8.0, but drainage comes first here: SSURGO maps about 29.4% of Michigan as poorly or somewhat-poorly drained, and wet ground rots its crown before pH ever matters.
Plant potato yam on a raised, gravel-amended berm so water drains fast and the crown stays dry. How to handle it →
What to actually do about these — and the constraints that apply to every Michigan grower, not just potato yam — is covered on the Michigan growing guide.
Timing shifts within Michigan
Michigan isn't one climate. In Luce County, the last hard freeze (28°F) holds until about May 22 — roughly 27 days later than the recorded state median — so plant potato yam to your county's window, not the statewide date.
County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). A parcel report resolves your address's own frost dates.
Where in Michigan Potato Yam Is Zone-Hardy
Potato Yam is rated for USDA zones 9–12. No Michigan county reaches it. Even Allegan County, the state’s mildest winter at zone 7a, sits below the plant’s zone 9 floor — so in open ground this one needs winter protection here, or a container that comes under cover.
Across those 83 counties Michigan’s winter-low ladder runs from zone 4a in Gogebic County to zone 7a in Allegan County — 3 USDA zones of spread, which is 30°F between the two counties’ average coldest night of the year. None of that range reaches the band potato yam needs, so here the statewide answer really is the answer.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. Potato Yam’s zone 9–12 band: Not verified. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Pollinator + Wildlife Value
Potato Yam draws native bees (low value). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, potato yam can only work that bloom inside Michigan's frost window — roughly 186 days, opening after the last 28°F freeze (Apr 19 - May 8) and closing at the first (Oct 12 - Oct 31), per NOAA Regional Climate Centers ACIS, 1991-2020. Pollinator value: We haven't confirmed this against a published source yet.
Good to Know Before You Plant Potato Yam
Potato Yam is listed as toxic to dogs, cats (all) at a moderate level. (Source: Cornell Poisonous Plants Database.) Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear.
Michigan Cooperative Extension
For Michigan-specific cultivar recommendations, planting calendars, and pest pressure for potato yam, the canonical source is MSU Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Potato Yam native to Michigan?
No — the USDA PLANTS Database lists Potato Yam as introduced rather than native in the Lower 48, so it is not part of Michigan's native flora. It grows here as a garden plant; pairing it with a few Michigan natives keeps local pollinators fed too.
Looking for plants that belong here? The Michigan growing guide lists plants that USDA PLANTS records growing in Michigan and that Kew and NatureServe Explorer both list in its native range, leaving out any that NatureServe flags as exotic there or that our audit holds.
State records: USDA PLANTS Database state-distribution data (presence, not state-level nativity), accessed 2026-10-19.
Common Questions About Growing Potato Yam in Michigan
When can I plant Potato Yam in Michigan?
Michigan's last spring hard freeze (28°F) clears between Apr 19 and May 8, and the first fall hard freeze lands between Oct 12 and Oct 31 (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 Michigan 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 Michigan?
Michigan spans USDA hardiness zones 4a-7a (USDA ARS PHZM 2023). Potato Yam is listed for zones 9-12, which do not overlap them, so there is no zone in Michigan where this page can call outdoor growing reliable. A parcel report resolves your own address's zone.
How many frost-free days does a typical Michigan site have?
A typical Michigan site sees ~186 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 Luce, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Potato Yam native to Michigan?
No — the USDA PLANTS Database lists Potato Yam as introduced rather than native in the Lower 48, so it is not part of Michigan's native flora. It grows here as a garden plant; pairing it with a few Michigan natives keeps local pollinators fed too.
How should I amend the soil for Potato Yam in Michigan?
Potato Yam prefers pH 5.3-8 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Michigan 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 Michigan?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores potato yam against your address's mapped soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Michigan
State-level data is a sketch. Your Growable Ground report scores potato yam against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.
Three things about your lot that Michigan potato yam averages can't show:
We read public map data around Michigan — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Michigan potato yam average
Explore More
Growing guides for potato yam
Explore Michigan county by county
Michigan carries 83 counties with their own USDA zone — a sample of the growing pages for potato yam there:
Where else potato yam grows
Potato Yam's zone band crosses state lines — these are the states closest to Michigan 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 Michigan
Michigan has a growing page for 889 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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