It is time to Chop ... Tropical Milkweed
It’s November, which means it’s time to plant cool weather veggies and cut back your non-native milkweed, also known as Tropical milkweed, Asclepias curassavica. I’m sure the idea of cutting back a flowering plant is a total bummer, and not vary appealing. Cutting Tropical milkweed twice a year is a healthy garden practice that will be beneficial in promoting the Monarch butterfly community.
Milkweed is one of those plants most commonly recommended for pollinator gardens to gardenistas and gardeners wanting to attract butterflies. Monarch butterflies rely on milkweed to complete their full life cycle. This is because milkweed is the only host plant for Monarch caterpillars, which is the second stage of the butterfly’s metamorphosis.
Since milkweed is the only host food for Monarch caterpillars, Mama Monarch butterflies gravitate to milkweed. The butterflies will lay their eggs on the underside of the milkweed leaves and within a few weeks the eggs will hatch. Once the butterfly eggs hatch, out climbs a very hungry caterpillar! The caterpillars eat and eat until it is time to form a chrysalis. The caterpillars crawl usually to a spot relatively close by to form into its next transformation stage of the life cycle. Within 14 days, the adult butterfly emerges from the chrysalis. All of the stages of the Monarch’s life typically happen close to milkweed.
Not all milkweed varieties are the same. Some are not native to Florida, like Tropical Milkweed. Tropical Milkweed, the non-native variety, is commonly sold in garden centers because it stays lush and red and yellow showy blooms almost all year long here in Central Florida. It also tends to volunteer in gardens more often because it’s blooming year round. If you’ve ever seen its seed pods, they are scattered near and far by the wind.
Tropical milkweed, Asclepias curassavica, Florida non-native milkweed plant in bloom in November.
Why does milkweed spread so easily? Check out these non-native, Tropical milkweed seeds blowing in the wind.
Florida native Milkweeds on the other hand tend to start losing their leaves and flowers late summer to early Fall. The native milkweed tend to stay dormant during the cooler months, which is when the Monarch butterflies begin their migration south and travel through Florida.
Florida native milkweed, Swamp milkweed blooming in June.
Garden ID Tip: Some non-native, Tropical milkweeds sometimes look very similar to Florida native milkweed, for example the Butterfly milkweed. If you break off a piece of the leaf and a white milky substance oozes from the stem, most likely that plant is the non-native variety.
Non-native, Tropical milkweed may be beautiful but this plant can introduce major problems to the Monarch butterfly community because of a parasite called Ophryocystis elektroscirrha most commonly referred to as OE. OE accumulates in the leaves of milkweed and once ingested by the Monarch caterpillars, the insect becomes infected with the protozoan parasite. Once infected, there are serious effects on various aspects of the butterfly’s life cycle and as a result the overall population. Very high levels of the OE parasite have been linked to major impacts in the Monarch’s abilities to fully expand their wings when transforming from the chrysalis which affects flight ability and therefore migration patterns. Infected butterflies have also been seen to have decreased body sizes, lifespan, and problems mating.
Monarch resting on a non-native yellow tropical milkweed plant.
If you currently have Tropical milkweed growing in your garden, you may be thinking, “YIKES! Should I pull it out? What should I do?!” Keeping your garden as free of this nasty parasite as possible does not mean yanking out all of your tropical milkweed. A good garden practice is cutting your tropical milkweed down to around six inches from the ground twice a year - once right before Thanksgiving and then again in June. Keep in mind, the parasite spreads through the leaves. By cutting the non-native milkweed twice a year, it prevents the OE from accumulating in the leaves. This will allow the butterflies to return from migration to fresh, non parasitic leaves.
When planning or planting a garden, try to choose native plants when possible. Native plants have adapted to Florida’s climate and weather patterns making them low maintenance and typically more resilient. The Florida Association of Native Nurseries (FANN) is a great resource for finding a native nursery nearest to you. Another option is planting natives plants from seed. Below are links to help you find both plants and seeds to help your future native planting needs.
Find Native Plant and Seeds
If you haven’t chopped your Tropical milkweed yet, it’s not too late to bring out the shears and yard clippers. This garden chore doesn’t take much time and trust me the milkweed will grow back! When trimming, this goes with anything in the garden, always disinfect your cutting tools after use to minimize the spread of any bad stuff throughout the garden.
Blog Sources:
https://nwdistrict.ifas.ufl.edu/hort/2017/12/14/time-to-cut-back-tropical-milkweed/
Native Swamp Milkweed in October with no blooms or leaves.