One of the slowest of herbaceous perennials to emerge from the soil in spring is the Butterfly weed (Asclepias tuberosa) with its bright green foliage and its sunny orange flowers, but they are well worth waiting for! These native butterfly magnets love full sun and well drained soils, especially in the winter. Plants develop strong taproots so it is best to plan where in the garden they will thrive because transplanting them later will be difficult.
Native flowers often have many common names, and Butterfly milkweed is also known as chigger flower and pleurisy root. Sometimes a name shares a reason why not to pick it, and a chigger flower says ‘pick at your own risk!’
Pleurisy root is a nod to the herbalist who only had plants to help heal, and it was used help drain excessive fluids to heal lung congestion.
Most milkweed plants earn their name because of the milky white sap that oozes out of the stems when broken. It was thought that the milky sap was needed for the Monarch caterpillars to feed on for their protection, but Butterfly weed does not have the milky sap and still provides protection from predators if the caterpillar feeds on it.
The bright orange, black and white spotted Monarch butterfly will sip nectar from many types of flowers including the Butterfly weed, but the yellow, white and black striped caterpillar will only feed on plants in the Butterfly weed family, often eating the plants down to the ground. Even if the Monarch caterpillars do eat the plants down to the ground, they will regrow quickly and produce more bright orange flowers for pollinators.
The bouquets of bright orange flowers mature into thin seedpods that split open to allow the tiny seeds with their silky tails to drift on the breezes and grow into more Butterfly weeds.
(Editor’s Note: Ginny Rosenkranz is a commercial horticulture specialist with the University of Maryland Extension.)