Tropical Milkweed is now Invasive!
Tropical milkweed (Asclepias curassavica) was once a go to larval host plant for monarch butterflies. As of June 2025 the plant status has changed. It is now listed as invasive in the entire state of Florida (north, central, south) on the UF/IFAS Assessment of Non-Native Plants and listed as a category II invasive on the FISC List of Invasive Plant Species.
Tropical Milkweed and OE
Tropical milkweed can host the Ophryocystis elektroscirrha (OE) parasite, which infects monarch butterflies. Infected monarchs may have deformed wings, a shortened lifespan, and struggle to emerge from their chrysalis. Unlike native milkweeds, tropical milkweed grows year-round in Central Florida. Since there is a ready food source, this encourages the monarch to stay all winter instead of migrating to Mexico. Scientists are divided on whether or not this is a good thing. Warmer winters mean that the monarch probably won’t freeze to death if they stay. However, some scientists believe that when monarchs don’t migrate, it makes them more susceptible to OE.
Remove and Replant with Natives
If you currently have tropical milkweed, consider removing it and replacing it with native milkweed. Gardening Solutions lists 21 native milkweeds for Florida. In Central Florida, there are three species that are commonly available at nurseries that specialize in native plants. A list of retail native nurseries is available at https://www.plantrealflorida.org/.
Recommended Native Milkweed Species
Swamp milkweed (Asclepias incarnata) has pink flowers and can grow into a large plant, up to five or six feet tall. It needs sun or part shade and lots of water, which makes it a great choice to plant near a downspout, by a pond, or in a low spot in your landscape. It will bloom summer through fall. Swamp milkweed is one of the most adaptable species of native milkweeds to grow in home gardens.
Aquatic milkweed (Asclepias perennis) has white or pink flowers and is fairly short, about two feet tall. It normally grows in swamps or along riverbanks, so it’s a good choice for water gardens, ponds, ditches, or other constantly wet spots that get full sun or part shade. It blooms from spring to late summer. The aquatic milkweed does not go dormant like many other species do.
Butterfly weed (Asclepias tuberosa), also called butterfly milkweed, has orange or yellow flowers and grows about two feet tall. It likes sun or part shade and is drought tolerant, so once established it can live in dry, sandy spots. Avoid overhead watering. It blooms in summer and early fall, providing a nectar source after the spring blooming flowers are done. In winter it will disappear but will grow back in late spring.
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