Monarchs: Going Native with Milkweed

Most folks know that monarchs need milkweed to lay their eggs, and for their caterpillars to feed. What most people don't realize, though, is just how many different species of milkweed there are - more than 140 worldwide. Knowing which milkweeds are native to and grow best in your area will make it easier to maintain healthy host plants for healthy caterpillars and butterflies.

In Florida, the most common milkweed available for sale is Asclepias curassavica, known as Tropical Milkweed or Scarlet Milkweed. This species of milkweed is not native to Florida, but has naturalized here due to its ability to thrive in our hot and sticky summers. There is some concern among the scientific community about the possible drawbacks to using non-native species to feed native butterflies, and also some evidence that A. curassavica may be invasive in some areas. For more on this topic, see the excellent article Native Habitats for Monarch Butterflies in South Florida on the University of Florida IFAS Extension website.

Choosing native plants when possible has undeniable benefits, but this isn't always as easy as it sounds. Florida also has several dozen native species of milkweed, most found only in the wild and some in very localized populations. Of these native species, the only one commonly found for sale is Asclepias tuberosa, commonly called Butterflyweed, and then only at local native plant nurseries. Occasionally, Swamp Milkweed (Asclepias incarnata) and Purple Milkweed (Asclepias humistra) are available as well. Learn more about Florida's native milkweeds by clicking here.

If you have the chance to plant these native species, we certainly encourage you to do so. One important note: Several of Florida's native milkweed species are also native to other parts of the country, and seeds are sometimes available for sale on the internet. The problem with these seeds is they are often not from Florida sources, and so can have difficulty growing here in Florida's very challenging climate. Try to seek native sources of milkweed seeds for best success.

We're always seeking local sources of native milkweeds for our butterflies. If you know of any within reasonable proximity to the Tampa Bay area, please drop us a line in the comments.

Milkweed Fun Facts:

• Milkweeds belong to the genus Asclepias, named for Asklepios, the god of healing in Greek mythology. Many cultures have used milkweed in folk medicine for a wide variety of maladies, including cancer, and as a purgative and contraceptive. (Herbal remedies containing milkweed should be used with great caution, as the sap in the plant is in fact toxic.) 
• The common name "milkweed" refers to the milky sap that leaks from the plant when a leaf or stem is broken. This sap contains latex, and milkweed was explored as a possible industrial source of latex rubber in the early 20th century, though never pursued on a wide scale.
• Milkweed is a host plant for more than just monarch butterflies: A whole group of butterflies known as Danaids use milkweed. Other Florida butterflies in this group include the Queen (Danaus gilippus) and Soldier (Danaus eresimus); the Tropical Milkweed Butterfly (Lycorea cleobaea) is found from southern Texas down through Central and South America. Old World representatives of this subfamily include the Plain Tiger (Danaus chrysippus), found in Asia and Africa, and the Malay Tiger (Danaus affinis), found from Thailand down through the Philippines.