Milkweed and the Importance of Monarchs as Pollinators

 

 The March meeting of the Seabrook Island Garden Club featured a talk on “Milkweed and the Importance of Monarchs as Pollinators” by guest speaker Christopher Burtt from the Clemson Cooperative Extension Service. Mr. Burtt is a 2015 Clemson graduate and serves as the Urban Horticulture Agent and Master Gardener Coordinator for Berkeley, Charleston and Dorchester Counties.

 Most people are familiar with monarch butterflies due to their relatively large size, their bright orange and black coloration, and their annual migration patterns. Like bees, butterflies are plant pollinators, and about one third of all crop production in the world depends on pollination. Sadly monarch populations have declined precipitously over the past two decades primarily due to habitat loss, although Mr. Burtt pointed out scientists believe the decline has not been as significant as it was originally thought to be.

 To understand what can be done to prevent further decline in the monarch population, it is important to understand this butterfly’s migration patterns and life cycle. Monarchs spend the winter months in central Mexico and begin to head northward in the spring where they lay their eggs on milkweed plants. These eggs hatch and grow into caterpillars that feed exclusively on milkweed before pupating and becoming the next generation of butterflies. Simply put, no milkweed means no monarch butterflies. Additionally, milkweed produces a milky sap that makes the caterpillars toxic to birds and unpalatable to other animals thus allowing them to survive.

 Effective conservation efforts involve planting native milkweed species to restore the breeding habitats of monarch butterflies. According to Mr. Burtt, South Carolina has 21 species of native milkweed but only three are common. He recommends planting Swamp milkweed (Asclepius incarnata), Butterflyweed (Asclepius tuberosa) or Aquatic Milkweed (Asclepias perennis). All native milkweed species are perennials. While milkweed grows readily in a wide range of wild habitats, it can be hard to establish in backyard gardens as it requires significant sunlight and moist but well drained soil conditions. Mr. Burtt nonetheless encourages gardeners to incorporate a few milkweed plants into any landscape plan to attract monarchs. Although non-native milkweed is easier to grow and more readily available at nurseries, some scientists are concerned that it has negative impacts on monarchs and their larvae. To avoid these risks, native milkweeds should be grown whenever possible.

 Right about now, the monarchs are beginning their journey northward and will be passing through South Carolina. We should do everything possible to ensure the prosperity of one of our most beloved pollinators. Whatever you do, don’t forget the milkweed!

 

—Submitted by Susan McLaughlin