Get the Dirt: May 2016

By Lynn Barber

Last month my article was about returning from a five-day Mexico vacation to view the Monarch butterflies prior to their leaving mountain sites for the United States and Canada. This month’s article is about the threats that remain and the reversal in the decline of the Monarch butterflies.

Each fall, Eastern United States and southern Canada Monarch butterflies travel up to 3,000 miles to central Mexico mountains for the winter, generally from November to some point during the following March. There are environmental and man-made threats to this migration process. The habitat loss at the Mexico sites is an issue that can involve illegal logging, expanded farming or bad farming practices. Other negative impacts include the absence/lack of milkweed en route, warmer temperatures causing earlier departure, later arrival, no place to go up the mountain and an increase in non-native milkweed, such as the Scarlet milkweed, which become invasive and can alter migration behaviors.

There is good news in that the United States, Canada and Mexico have agreed to protect Monarch butterflies. Solutions involve increasing the development of ecotourism, research and education, better forestry and farming practices, sanitation and disposal, more efficient land use, environmental responsibility, planting and creating native milkweed gardens, which are important food sources for Monarchs.

Butterflies need host plants for larvae (most important) and nectar plants for adults (less important because of the availability of many alternative nectar plants). For a list of native larval host and nectar plants, see the University of Florida publication, Native Habitats for Monarch Butterflies in South Florida, by Rebecca G. Harvey, Patricia L. Howell, Carol Morgenstern, and Frank J.
Mazzotti, at This document contains a link for Asclepias species that are native to each region in the United States. Review Butterfly Gardening in Florida, by Jaret C.
Daniels, Joe Schaefer, Craig N. Huegel, and Frank J. Mazzotti, at, for even more information. When our group left Mexico, the guide said, “Go home and make a difference.” All of us can. Hopefully, we will.