By Amy Dunlap, Extension Agent, Davidson County

Each fall, monarch butterflies migrate from the northern United States and Canada to the mountain forests of central Mexico. This journey can stretch up to 3,000 miles and takes the butterflies across multiple states and landscapes. Tennessee lies right in the middle of their flyway, so the monarchs we see in September are on their way south.

The monarchs that make this trip are often called the “super generation.” While summer generations live only two to six weeks, the fall generation survives for eight to nine months. That extra lifespan allows them to complete the long flight to Mexico, spend the winter clustered together in oyamel fir forests, and then begin the journey north in the spring. It takes several generations to return north again, completing the full cycle.

Monarchs depend on two things to survive: milkweed for their caterpillars and nectar-rich flowers for the adults. Without milkweed, monarchs cannot reproduce, since it is the only host plant where they lay eggs. In Tennessee, important native milkweeds include common milkweed (Asclepias syriaca), swamp milkweed (A. incarnata), butterfly weed (A. tuberosa), and whorled milkweed (A. verticillata). Planting these species provides breeding habitat for monarchs and supports other pollinators as well.

Nectar plants are equally important for fueling migration. Native species like goldenrod (Solidago spp.), asters (Symphyotrichum spp.), ironweed (Vernonia spp.), and Joe-Pye weed (Eutrochium spp.) bloom in late summer and fall, right when monarchs are moving through. These pair well with other pollinator-friendly garden plants such as zinnias, lantana, salvias, and Mexican sunflowers. Together, they create a continuous supply of food from spring through fall.

By planting native milkweed and nectar sources, and by avoiding pesticides, Tennessee gardeners can play a direct role in supporting monarchs as they pass through our state each year. Even small plantings in backyards, schools, and community spaces add up to meaningful habitat along the migration route. And exhibits like the one at the Nashville fair give us the chance to share these stories with the public, sparking interest and inspiring more people to take action for monarchs.