Swamp milkweed (Asclepias incarnata) is a vital plant for supporting the survival and migration of the monarch butterfly. It serves as the only host plant for their caterpillars to eat, providing essential sustenance for their development. Additionally, the plant offers vital nectar for adult monarchs, directly supporting their survival and migration. While swamp milkweed is important, planting a diversity of native milkweeds is best for overall monarch health. By including swamp milkweed in your garden, you can contribute to the conservation of monarch butterflies and support their population.