Monarch butterfly populations have been declining over the past decade, with sharp declines in the last few years. What can gardeners do to help?
Support the declining monarch butterfly population by planting beneficial habitat that includes the milkweed plants their larvae need to survive.
Milkweed, the only plant on which monarchs lay their eggs and the only source of food for baby caterpillars, is disappearing all across the United States due to herbicide use and land conversion.
Monarchs are in trouble because of the elimination of milkweed that used to grow in farm fields. Grow a patch of milkweed in your backyard, which will provide food for monarch caterpillars.
Monarch butterflies making their way back to North America from their winter habitat in Mexico follow a well-marked trail. These striking orange-and-black butterflies are looking for one thing: milkweed (asclepias). And when you plant milkweed in your garden, it’s like rolling out a welcome mat for monarchs.
Spring is the beginning of the monarch’s breeding season, and milkweed is crucial to survival of the species. Many flowers — especially native plants — are terrific sources of nectar for monarch butterflies, but milkweed leaves are the only food monarch caterpillars eat. Monarchs butterflies lay their eggs on milkweed plants so the tiny caterpillars will have access to food the moment they hatch.
Common milkweed plants are tall (3 feet), thin, summer-bloomers. The flower cluster forms a globe atop the plant’s rigid stem. The flowers come in various shades of pink, and they are fragrant flowers. Leaves are broad-oblong and light green. Seed pods that resemble small cucumbers succeed the flowers.
The pods, in turn, burst open in late summer to early fall, exposing their seeds. The seeds are attached to white silky hairs, meaning the slightest wind will distribute them.
Milkweed seeds can be sown directly in the ground, but starting them indoors improves germination and lets you nurture the seedlings.
Choose a spot in sun: butterfly plants need at least six hours of sun a day. Almost any kind of soil is acceptable, but light, well-drained soil is best. A good butterfly garden also provides shelter from the wind: the sunny side of a solid fence, garage, or garden shed is a good place for a waystation. Dense plantings, with tall and short plants, help with the wind, too, and also give butterflies shelter from predators.
Many scientists are concerned about the eastern population of monarchs, which summer east of the Rocky Mountains. This group is occurring in ever smaller numbers, and its survival may be threatened by a series of natural disasters in the Mexican wintering grounds, as well as by reduced acreage of milkweed plants in their summer home.
The monarch butterfly exhibits the most highly evolved migration pattern of any known species of butterfly or moth and perhaps any known insect.