Maine · zones 3b–6a
When to plant potatoes in Maine.
Sow between Mar 31 to May 3 in a typical year, keyed to Maine's median last frost around May 8. A second, fall sowing fits Jun 19 to Jul 2. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Potatoes dates for a typical Maine season.
Direct sow
Mar 31 to May 3
Keyed to the ~May 8 last frost. Sow 4" deep, 12" apart.
Fall round
Jun 19 to Jul 2
Counted back from the ~Oct 7 first frost.
Harvest
~90 days later
~3 lb per plant over ~1 weeks.
Maine spans more than one climate: Zone 5 is the most common zone, but the state runs 3b to 6a. 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.
In Maine: watch for
The pests that find potatoes here.
A middle-length season, about 152 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: Maine gives potatoes about 152 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 Maine: questions
When should I plant potatoes in Maine?+
In a typical Maine year, sow potatoes between Mar 31 to May 3, keyed to the state's median last frost around May 8. There's also a fall window: Jun 19 to Jul 2. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is Maine?+
Maine spans zones 3b–6a, mostly zone 5. 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.