Monarch butterflies have a multi-generational migration that can span thousands of miles and three continents. In 1996, an estimated 1 billion monarch butterflies migrating to forests in central Mexico covered almost 50 acres. In those same forests in 2015, they only covered 2.79 acres, the second smallest number on record.
Mexico has preserved the few forest areas where the butterflies over-winter. A monarch migration map is available online at Monarch Migration to show their route to these forests.
Milkweed habitat loss is due to development — both rural and urban, excessive mowing and the widespread use of glyphosate, the main ingredient in Monsanto’s Roundup® herbicide on crops and roadsides. Herbicide use in the U.S. for soy and corn killed off 58% of the country’s milkweed from 1999 to 2010, resulting in a monarch decline of 81%. This suggests that the monarchs are becoming extinct.
The problem isn’t only the lack of milkweed. Iowa State University found evidence that pollen from bioengineered corn could be deadly for Monarch butterflies. Monarch butterfly caterpillars were seven times more likely to die when they ate milkweed plants carrying pollen that drifted over from Bt corn, compared to traditional corn. Fifty percent of the monarchs that make it to Mexico typically come from the Corn Belt.
Milkweeds all carry the name of the Greek god of healing and medicine, ‘Asclepias’. The medicinal qualities of their roots were well known to indigenous peoples. However with our valuable pollinators relying so heavily on this plant, using other plants for medicine may be the prudent choice.
There are over 100 species of milkweed. One of the most popular is the beautiful orange butterfly milkweed which grows on my farm along with the stunning purple milkweed. When I first started my medicinal wildflower farm, there were very few milkweed stands. Though some people save the seed, cold stratify, start the plants indoors, and plant out after the fear of frost, I like to plant my seeds in November so that they will cold stratify outdoors. A few months prior to planting the seeds, cover a fresh patch of earth to kill any grass and allow a few frosts to heave up and disturb the soil. Then remove the cover exposing the soil and after a nice rain, press the seed into the earth. This has allowed me to create several hardy, drought-tolerant stands of perennial milkweeds. This method will not work for the warm weather annual milkweeds.
There are many organizations working to save the butterfly, and they all agree that we need to restore the milkweed population. Just 1 plant cannot sustain more than a couple of caterpillars. So plant a healthy sized patch near other native nectar plants for the most benefit.
It is important to plant milkweed that is native to your own region. Some milkweed sold in big box stores are not native to your area and could increase the incidence of a deadly protozoan parasite that causes more harm than good. The butterfly milkweed plant that Baker Creek sells seasonally has been mapped for the Northeast and Southeast regions.
Let’s all do our part to support these amazing creatures that do so much for us by planting milkweed, stopping the use of herbicides, and voting with our dollars for non-GMO corn.
Special thanks to Samantha Stolle from the MO Department of Conservation and Missourians for Monarchs.
Jamie Jackson, Butterfly Medicine Woman, is a staff member of Heirloom Gardener. She is also the owner of Missouri Herbs, an organic permaculture-based farm that focuses on growing Missouri naturalized medicinal plants that are crafted using traditional methods into herbal products. Check out her herbal products and blog at Missouri Herbs.