Best Time to Plant Annuals in Wisconsin

In Wisconsin, the safe planting window depends on your location — earlier in Madison, later in Superior. While frost risk drops after mid-May, many annuals (marigolds, zinnias, impatiens) sulk or die if nights dip below 50°F. Cold-tolerant annuals like alyssum, pansies, million bells, and petunias handle cooler nights better.

Plant in stages: start with cold-tolerant varieties or containers you can move indoors on chilly nights. Wait until Memorial Day weekend for heat-loving annuals. A little patience prevents plant loss and ensures vigorous growth all summer.