During Eileen Malone-Brown's presentation on March 12, 2015 to the Potowmack Chapter of The Virginia Native Plant Society at Green Spring Gardens, she spoke about the importance of native plant pollinators. BAEE's award-winning book American Botanical Paintings: Native Plants of the Mid Atlantic contains portraits of plants and pollinators, as well as information about their dependence on one another.
One such critical relationship between plant and pollinator is the swamp milkweed and the monarch butterfly. The swamp milkweed is the larval host for the monarch and the queen butterfly. When the swamp milkweed foliage dies off in the fall, a generation of sexually immature monarchs migrates from their breeding grounds in the northern U.S. and southern Canada to the Abies religiosa (sacred oyamel fir) forests in central Mexico where they wait for 5 months during winter. They migrate north again to the breeding grounds when the swamp milkweed begins to bloom in spring. Female monarchs will lay their eggs only on milkweed plants.
The November 17, 2014 New York Times article, "For the Monarch Butterfly, a Long Road Back" by Liza Gross, discusses how there are possible links between the disappearance of native swamp milkweed and the decrease in the monarch butterfly population.
Between 1999-2009 nearly 60% of native Midwestern milkweeds vanished. Since then approximately 80% of monarch populations disappeared in the Midwest and in Mexico. People have tried replanting milkweed in native plant gardens but the only widely available variety for planting is tropical milkweed, which produces lush foliage in the fall. This fall foliage may trick the monarchs into staying and reproducing in winter when caterpillars may freeze and food is scarce. This also makes the monarchs susceptible to parasites, which will lead to further die off. Dara Satterfield, the researcher in Liza Gross's article, says
We've learned the hard way with migratory bison and whooping cranes that once we lose a migration, it is close to impossible to bring back…
From The New York Times, November 17 © 2014 The New York Times Company. All rights reserved. Used by permission and protected by the Copyright Laws of the United States. The printing, copying, redistribution, or retransmission of this Content without express written permission is prohibited.
You can watch the 2,000-mile migration of the monarchs to the oyamel fir forests in the PBS documentary The Incredible Journey of the Butterflies. (Aired November 30, 2011 on PBS.)
Native plant societies and nurseries in Canada and the U.S. can provide guidance for restoring swamp milkweed and other native plants. The American Horticultural Society's Native Plant Societies website provides a quick reference list of one per state / province for native plant societies in your area. Additional resources are listed in the footer of this website.