The great migration is set to begin in the next few weeks as millions of monarch butterflies begin their journey south across Wisconsin.
Over the past few weeks, increasing numbers of monarch butterflies, as well as healthy caterpillars hosting upon milkweed throughout the state, have been observed. This activity sets the stage for the annual migration of monarchs south to their wintering grounds in the mountains of central Mexico.
For gardeners and homeowners across our state, there are a number of ways we can help monarchs on the move.
The easiest way is to simply provide nectar plants throughout the fall season, lasting at least through Halloween.
Many gardeners tend to clean up gardens and flowerbeds after the Labor Day weekend. This eliminates a great source of nectar plants for migrating monarchs.
Instead of cleaning up your garden beds after the summer season, plant fall blooming annuals and perennials to keep the show going through Halloween. This provides backyard beauty, as well as a precious source of food for migrating monarchs.
Some of the best nectar plants for monarchs during late summer and fall are annuals such as zinnias, verbena, dahlia, cosmos, heliotrope, sunflower, lantana and others.
Perennials that are excellent choices for late summer and fall are purple coneflower, ironweed, goldenrod, black eyed Susan, cup plant, cardinal flower, joe-pye weed, turtlehead, asters, rattlesnake master and more.
Many butterfly enthusiasts will also place cut up fruit pieces, orange slices, watermelon rinds, banana peels and other scraps in the garden on plates or platters for the butterflies to enjoy. You'll be surprised at how many butterflies are drawn to this easy food source.
It is the last generation of Monarch butterflies transformed each summer season that makes the journey south to Mexico. Genetically implanted with all the directions and knowledge they need to journey across our continent, this "super generation" of monarchs begins their migration south.
Migration of monarchs is especially heavy along waterways, such as the Mississippi River, Wisconsin River and the shoreline of Lake Michigan. The butterflies use these natural corridors as highways on their journey south. In many locations, nightly roosts of monarchs can be impressive, with hundreds or thousands of butterflies resting at sunset for the coming night.
The migration peaks during late August to mid-September, with straggling monarchs moving through well into November from the north. As long as warm weather allows, monarch butterflies will continue to drift south with the winds.
Once they arrive to their wintering grounds in Mexico, the monarchs will gather by the millions in the forest trees, resting in the cool, misty mountains for much of the winter season before returning north in mid-March.