The debate continues. Should we plant tropical milkweed (Asclepias curassavic) for monarchs or not? Yesterday, I observed an entire flower bed neatly planted with the species at Mueller Austin, a high-density development designed with sustainability in mind. After attending last weekend's Texas Pollinator Powwow in Kerrville, I'm of the opinion that we should not this species.
That's because I listened to Dara Satterfield discuss research findings related to the nonnative species. She's with the Monarch Health Project, a citizen science project being conducted by Satterfield and other biologists with the University of Georgia.
According to the project's website, participants "track the prevalence of the protozoan parasite Ophryocystis elektroscirrha (OE) in monarch butterflies. This parasite does not infect humans but can make butterflies sick: Monarchs infected with OE may be too weak to emerge properly from their chrysalises and can die at this stage. Or, infected monarchs can look completely normal but cannot fly as well or live as long as healthy monarchs."
What the research is showing is that "tropical milkweed in warm areas can encourage OE," Satterfield said last weekend. To protect monarch health, she also said, cut the tropical milkweed to the ground in the fall and even cut it monthly until spring.
What I took away is that we should plant only regional milkweeds. Better yet, plant native milkweeds from seeds that originate in your area. I confess that I haven't adhered to that strictly. In fact, at the Powwow I bought an Asclepias tuberosa, which is native to Texas but not Central Texas.
After James and I got home from Kerrville, I cut our two tropical milkweeds nearly to the ground. I may even pull them up. I just haven't quite decided yet.......