DibbleWhen to plant corn 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 corn in Zone 4
| Task | Window |
|---|---|
| Direct sow | May 17 to May 31 |
| Estimated harvest | Jul 31 to Aug 10 |
The harvest estimate counts 75 days to maturity, then a picking window of about 10 days. These windows use typical frost dates for Zone 4; Dibble pins them to your exact ZIP code.
Get reminders for these exact dates
Dibble turns your ZIP code into a full planting calendar and reminds you on the right day. Free to start, no account needed.
Sweet Corn in a Zone 4 season
Zone 4 gives about 134 frost-free days. Sweet Corn needs roughly 75 days from sowing. That leaves about 59 days of slack, enough for one full crop with a little room for a cold spring.
How to grow corn
Sow corn a week after last frost in warm soil. Plant in blocks of several short rows, not one long row, for good pollination.
Companion plants
Good neighbors for Sweet Corn:
Better kept apart:
Sweet Corn in other zones
Not in Zone 4? Pick your zone for the same dated windows.
Keep exploring
Sweet Corn: the full growing guide · The Zone 4 planting calendar · Every crop and zone
Plant at the right time this season
Dibble builds your calendar in under a minute. Free to start, no account needed.
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.