It seems as though most people are aware of the importance of growing flowers as a nectar source when trying to attract butterflies to one’s yard but not everyone knows about the importance of host plants. A host plant is a certain plant that a butterfly will lay its eggs on and will then be eaten by the caterpillars that hatch. *Keep in mind that host plants are intended to be eaten and will have damaged leaves or can become totally defoliated. This is a good thing!*
Some butterflies have only one host plant. A common example of this is Monarch butterflies only laying their eggs on species of milkweed. Lucky for us, (and the monarchs), Florida is home to 21 species of native milkweed. Milkweed contains a variety of chemical compounds that make monarch caterpillars poisonous to potential predators. Three excellent species for home gardens include Butterfly Milkweed (Asclepias tuberosa), Pink Swamp Milkweed (Asclepias incarnata), and White Swamp Milkweed (Asclepias perennis).
Another example is Passionflower. Gulf fritillary and Zebra Longwing butterflies lay their eggs on species in the genus Passiflora (Passionflower). Much like monarchs and milkweed, Passionflower contains toxins that gives Gulf fritillary and Zebra Longwings an unpleasant taste and makes them poisonous to predators. Purple Passionflower (Passiflora incarnata) is a lush green vine with one of the most stunning flowers imaginable. Another less showy native Passionflower eaten by gulf fritillary and Zebra Longwings is the Yellow Passionflower (Passiflora lutea).
Many plants found in an herb garden such as parsley, carrots, dill, and fennel will attract the Eastern Black Swallowtail. A Florida native wildflower, Zizia aurea (Golden Alexander), is also in the carrot family and will serve as a host for Black Swallowtails. To deter predators, Swallowtail caterpillars will extend an orange snake tongue-looking organ from its head called an osmeterium. In my opinion it is very cute to witness but surely terrifying to a would-be predator.
The Giant Swallowtail caterpillar feeds on the foliage of citrus trees as well as a few native trees including hop tree (Ptelea trifoliata). Do not fret, they will not cause major damage to your citrus trees and you will get to observe Florida’s largest butterfly as a result. An interesting thing to note about this caterpillar is its clever disguise of looking exactly like bird droppings.
Why have butterflies as just passing guests when you could have them as permanent residents in your garden? Watching a butterfly go through its entire life cycle is very exciting and rewarding! I encourage you to make host plants a part of your garden today.
*This article was written by Savannah, Greenhouse Manager at Tallahassee Nurseries