When to plant onions in Zone 6

In Zone 6, the last spring frost usually passes around April 21 and the first fall frost arrives around October 17, leaving about 179 frost-free days. The windows below are computed from those frost dates, with the same math the Dibble app uses.

Generous season. Spring and fall plantings both productive.

Planting windows for onions in Zone 6

The harvest estimate counts 100 days to maturity, then a picking window of about 14 days. These windows use typical frost dates for Zone 6; Dibble pins them to your exact ZIP code.

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Onion in a Zone 6 season

Zone 6 gives about 179 frost-free days. Onion needs roughly 100 days from transplant. That leaves about 79 days of slack, so there is room for a late start or a second planting.

How to grow onions

Start seeds indoors about 8 weeks before planting out, or use sets. Match the variety to your day length (short-day types near the equator, long-day types far from it) and plant out in the cool part of the year. Cure the bulbs in dry weather once the tops fall over.

Companion plants

Good neighbors for Onion:

Better kept apart:

Onion in other zones

Not in Zone 6? Pick your zone for the same dated windows.

Keep exploring

Onion: the full growing guide · The Zone 6 planting calendar · Every crop and zone

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Dates are estimates based on typical frost dates for the zone. Your yard has its own microclimate, so use them as a starting point and adjust as you learn your space.