Did you know that the only plant that Monarch butterfly larvae eat is Asclepias? It is also known as Milk Weed or Butterfly Weed.
The tall pink variety, commonly known as Swamp Milkweed, is indigenous to New Jersey. The beautiful butterfly gardens in the Fanwood Nature Center have some well established specimens. Butterfly Gardens at several schools and backyards in Scotch Plains and Plainfield also have this versatile plant.
The widespread use of herbicides has forced the native Asclepias Incarnata onto the endangered list. Scientists have genetically modified strains of corn to be resistant to a very common weed killer so that entire fields can be sprayed with it. The corn plants survive, but all other plants do not. The beautiful pink flowering plant that used to grow profusely at the edges of fields and roadsides has now become scarce, endangering the Monarch population.
The plant is a host, nectar and shelter plant for all stages of Monarch development. Adult Monarchs are attracted to the flowers as a source of nectar. The tall, stiff stems provide an excellent site for egg laying. When the eggs hatch, the caterpillars have their only food source immediately available (Aren't mothers smart?). The milky latex sap of the plant also makes the larvae unpalatable to birds and other predators.
There are several cultivars of Asclepias that will grow well in your Scotch Plains or Fanwood garden. A. Incarnata will thrive in the full sun in average to moist soil. It is a good choice for your rain or bog garden. It will get three to four feet tall and is deer resistant. The fluffy flowers and enchanting vanilla fragrance make it an ideal plant for the back of your mixed perennial border. These plants are hardy in USDA Zones 3 to 7 (for an explanation of USDA Zones, see below), they are very slow to break dormancy in the spring. Patience and clear plant markers are recommended. This plant is available in a few sizes.
A. Tuberosa is also perennial here in Zone 6B. There are a few varieties of bright sunny yellow, cheerful orange, radiant red and bi-colors. This plant has an exceptionally long season of bloom. Its expected height of 18-24 inches makes it an ideal choice for mid-border. A. Tuberosa can tolerate dry soil and makes an excellent cut flower. The voracious Scotch Plains deer tend to avoid this one as well.
A. Curvassia, or Tropical Milkweed, must be grown as an annual here in New Jersey, but its vibrant colors make it worth the replanting. Hummingbirds love the bi-color yellow-red flowers almost as much as the butterflies do. This plant is available in the spring in cell packs and small pots. It grows 12-18 inches and loves a sunny spot.
All of the Milkweeds produce a banana-shaped seedpod in the late summer and fall, which opens to reveal silky white fibers with small brown seeds attached. The fluffy strands act like parachutes for the seeds to be carried by the wind to new places to germinate. Some species of birds will use the fibers as nesting material. The seed pods add beautiful textural interest when the bright colors of summer begin to fade.
Butterflies, like frogs, are sensitive barometers of ecological health. The Monarch population is rising again with the efforts of conservationists to make its only food supply more readily available. Plant some milkweed and bring these exquisite "flying flowers" to your yard.
An explanation of United States Department of Agriculture "planting zones:" They are regions defined by a 10 degree Fahrenheit differential in the average annual minimum temperature. Essentially, the higher the numbers, the warmer the temperatures for gardening in those planting zones. There are 11 zones in the United States and southern Canada, and each zone is split into parts A (warmer) and B (cooler). Scotch Plains is in Zone 6B.