Ohio · zones 5b–6b
When to plant potatoes in Ohio.
Sow between Mar 18 to Apr 20 in a typical year, keyed to Ohio's median last frost around Apr 25. A second, fall sowing fits Jun 27 to Jul 10. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Potatoes dates for a typical Ohio season.
Direct sow
Mar 18 to Apr 20
Keyed to the ~Apr 25 last frost. Sow 4" deep, 12" apart.
Fall round
Jun 27 to Jul 10
Counted back from the ~Oct 15 first frost.
Harvest
~90 days later
~3 lb per plant over ~1 weeks.
Ohio spans more than one climate: Zone 6 is the most common zone, but the state runs 5b to 6b. That's why the planner works from your ZIP code's frost dates, not your zone: mountain and coastal gardens in the same state can be three weeks apart.
Ohio growing notes
Ohio's potato ground splits into two very different jobs.
Hilling matters more on clay
Potatoes form tubers in the loosened ridge of soil you hill up around the stems, and how much work that takes depends on which half of Ohio you garden in. The till plains loam across western Ohio hills easily with a hoe and drains fast enough that rot is rarely the problem; the clay-heavy ground common in the northeast compacts under its own weight and needs real amendment before it will hold a proper ridge.
On clay, work 2 to 3 inches of compost into the row before planting and hill in 2 or 3 passes rather than one big mound, because clay hilled too aggressively in one go seals into a crust that sheds water instead of absorbing it. The test for whether a hill is doing its job: push a finger into the ridge a week after hilling. It should crumble, not compact into a ball.
The blight that named a famine, growing in your garden
Late blight, the same Phytophthora infestans that triggered the Irish potato famine in the 1840s, favors cool weather to get going, sporulating fastest through a mild, overcast stretch, the kind cool enough that a jacket still feels right at dawn, but it does not quit until afternoons push past about 95 degrees, so an ordinary run of Ohio summer heat does far less to shut it down than gardeners here tend to assume. It spreads just as readily on potato foliage as it does on tomatoes planted nearby whenever that favorable window opens. Keep the two crops in separate parts of the garden and never let a compost pile of tomato or potato vines sit near either bed, since the pathogen survives on infected plant tissue.
Watch for dark, water-soaked blotches on lower leaves that spread within days into brown, papery patches, especially during a run of 60-to-70-degree days with dew lingering on the leaves past mid-morning, the weather that actually favors this disease over a hot, dry stretch. Pull and destroy infected foliage immediately rather than composting it, and if blight takes hold late in the season, cut the vines at ground level 2 weeks before digging so spores cannot wash down onto the tubers.
Curing decides how long the harvest lasts
A potato pulled straight from the ground has thin, easily scuffed skin, and skin that thin will not survive a winter in storage. The test for readiness: rub a tuber with your thumb. If the skin slides or tears, the plant needs more time; if it holds firm under real pressure, the crop is ready to dig.
Cure freshly dug potatoes for 1 to 2 weeks somewhere that stays around 50 to 60 degrees and out of direct light, which thickens the skin and heals over any nicks from the fork. Skip curing and a bruised potato that would have kept for months instead softens and rots within a few weeks in the pantry.
In Ohio: watch for
The pests that find potatoes here.
A middle-length season, about 173 frost-free days, means potato overlaps colorado potato beetle for a stretch each summer. Check plants every week or two and treat early.
Striped beetles and orange grubs eating the leaves.
Organic fix: Handpick adults, crush the orange egg clusters, dust with diatomaceous earth.
Dark greasy blotches after cool, wet spells.
Organic fix: Pull infected plants fast, keep leaves dry, use neem as a preventive.
Common scab
Rough, corky patches on the skin, raised on some tubers and sunk into pits on others.
Organic fix: Keep the bed evenly moist through the weeks right after tubers set, rotate away from potatoes, and pick a scab-resistant variety next time.
Your season math: Ohio gives potatoes about 173 frost-free days, and it needs roughly 90 days to a first harvest. It's a one-planting crop, so time that single sowing well.
Planting potatoes in Ohio: questions
When should I plant potatoes in Ohio?+
In a typical Ohio year, sow potatoes between Mar 18 to Apr 20, keyed to the state's median last frost around Apr 25. There's also a fall window: Jun 27 to Jul 10. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is Ohio?+
Ohio spans zones 5b–6b, mostly zone 6. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many potatoes plants do I need?+
Depends who you're feeding. The crop page has exact counts per household size, or the free planner does the math for your family in about 60 seconds.