Aquatic Milkweed

While monarch butterflies abound in Central Florida, it can be difficult to get your hands on the native milkweeds they use as a host plant for their caterpillars. Most milkweed sold in Florida nurseries is the non-native Tropical Milkweed (Asclepias curassavica), which some studies indicate could be causing harm to the general monarch population. So we were pleased earlier this year to get a small pot of Aquatic Milkweed (Asclepias perennis), a native Florida species with gorgeous white flower clusters.

As its common name indicates, Aquatic Milkweed requires consistently wet soil. Ours is planted in the Savage Garden, which is a bog garden environment. It sits in an inch or so of water at all times and also receives plenty of sun, and these conditions have allowed it to flourish.

A. perennis is a fairly small plant, topping out around 2 feet. The flower clusters have pink stems and sometimes the flowers may have a pinkish tint. The flowers are followed by seed pods that look much like those of other milkweeds, but with an interesting difference: the seeds of Aquatic Milkweed lack the feathery attachments other milkweed seeds have to allow for wind dispersal. Instead, Aquatic Milkweed seeds are hydrochorous - they fall into the water and float to their new homes.

Like many native milkweeds, Aquatic Milkweed is suffering from habitat loss. Locally, we've observed a large patch of A. perennis growing in nearby Lettuce Lake County Park along the Hillsborough River. It is propagated by some native plant nurseries - we bought ours from Sweet Bay Nursery in Parrish - and is worth seeking out if you have a perpetually wet spot in your garden that can sustain it.