When to Plant Potatoes

Planting time for potatoes is set by your frost dates, not by the calendar month. Sow directly in the garden about 2 weeks before your last frost, as soon as the ground is workable. From there it takes roughly 90 days to the first harvest. Potatoes is a half-hardy crop, and it keeps going about 10 days past a light frost, which is what makes a fall crop worth planting. Pick your zone below for exact dates, or find your zone by ZIP if you are not sure which one you are in.

A fall potato crop works in zone 8 and warmer, planted in late summer from certified seed pieces that have broken dormancy. Because it is a half-hardy crop, the fall sowing has to finish before the first frost with no margin for error, so the sow-by dates in the table above are hard deadlines rather than suggestions.

Fall dates are counted backward from your first frost, not forward from a sowing date. Take the 90 days potatoes needs, add about two weeks because growth slows once days shorten after the equinox, then subtract the roughly 10 days potatoes keeps going once light frost arrives. That is 94 days before your first frost. The coldest zone where this still works on the averages is Zone 5a.

For the whole-garden version of this arithmetic, see the fall planting calendar by zone, and how to read and stretch your first frost date.

Potatoes grow well next to beans (bush) and corn. Keep them away from tomatoes, cucumbers, sunflowers, squash (winter) and eggplant. Shares blight with tomatoes and eggplant, and sunflower roots release compounds documented to stunt potato growth. The full grid for all 24 crops is in the companion planting chart.