When to plant rosemary in Zone 4

In Zone 4, the last spring frost usually passes around May 10 and the first fall frost arrives around September 21, leaving about 134 frost-free days. The windows below are computed from those frost dates, with the same math the Dibble app uses.

Cool climate with a brief warm window. Indoor starts and season extension help.

Planting windows for rosemary in Zone 4

The harvest estimate counts 120 days to maturity, then a picking window of about 200 days. These windows use typical frost dates for Zone 4; Dibble pins them to your exact ZIP code.

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Rosemary in a Zone 4 season

Zone 4 gives about 134 frost-free days. Rosemary needs roughly 120 days from transplant. That leaves about 14 days of slack, which is tight. Start indoors where you can and do not sow late.

How to grow rosemary

Set out a transplant after the last frost in full sun and sharp drainage. Tender, shelter or pot it up over cold winters.

Companion plants

Good neighbors for Rosemary:

Rosemary in other zones

Not in Zone 4? Pick your zone for the same dated windows.

Keep exploring

Rosemary: the full growing guide · The Zone 4 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.