What do Monarch butterflies eat?
Mecosta County Michigan
The answer depends on the life stage of the butterfly, as well as the time of year.
While a larva (or caterpillar) the monarch eats only plants in the Milkweed family. In your county, common milkweed (Asclepias syriaca) and swamp milkweed (Asclepias incarnata) are both fairly abundant. Swamp milkweed can also be found in local nurseries.
Adults depend on nectar as a food source, provided by many species of blooming plants, depending upon the time of year. The lifecycle of the monarch repeats 4-5 times per year and in Mecosta, you can find adult butterflies from June through September. This means there is great seasonal variability in their nectar sources. In late summer (around Labor Day) you'll see adult monarchs fueling up on nectar for their migratory flight. They will nectar on goldenrods, ironweed, and liatris, for example.
To continue learning more about milkweeds and monarchs, I suggest this website: https://monarchjointventure.org/monarch-biology. MSU also offers monarch resouces and citizen science programs, like Monarch ReGrow, https://www.canr.msu.edu/msumilkweedregrow/ . I hope they help as you learn more about these amazing animals and their conservation needs.