Zone 5 gardens experience a winter cold around -10 to -20°F; however this zone is also benefitted from ocean influence and lower latitudes.
Zone 5 stretches along Newfoundland and Nova Scotia and along the seacoast of Maine and New Hampshire in the eastern United States. In the western United States, it continues through western Massachusetts and midstate New York, northern Pennsylvania, Ohio, Indiana and Illinois, much of Michigan, southern Iowa and Nebraska, northern Missouri and Kansas, and eastern Colorado.

