A new law in Michigan bans noxious weeds and includes protections for milkweed.
The law is meant to help eradicate certain noxious weeds. Townships, villages, and cities can have a lien for expenses in controlling the weeds. Governing bodies can also appoint commissioners of noxious weeds, define their duties, and pay them.
The law lists which plants are to be considered noxious weeds. The list includes Canada thistle, dodders, mustards, wild carrot, bindweed, perennial sowthistle, hoary alyssum, giant hogweed, ragweed, poison ivy, poison sumac, and any other plants “regarded as a common nuisance” by governing bodies.
There is part of the law that states “noxious weeds does not include milkweed.” Milkweed is widespread and often found in fence rows, on roadsides, in fields, and in prairies and pastures. It tolerates light shade, but generally prefers full sun.
According to the USDA, common milkweed is “nature’s mega food market for insects.” There are more than 450 insects known to feed on some portion of the plant. It’s among the most important food plants for monarch caterpillars.
In the caterpillar stage, monarchs feed only on the leaves of plants in the milkweed family. A decline in milkweed has led to a decline in the population of monarch butterflies. If you have space to spare, planting milkweeds provides food for monarchs.
Milkweed contains various levels of cardiac glycoside compounds, which makes the plant toxic to most insects and animals. For some insects, the compounds become a defense. That’s because they can store them in their tissue, making them inedible or toxic to other animals.
Monarch butterflies use that defense so that birds leave them and their caterpillars alone. Northern monarchs feeding on common milkweed don’t build up much of the toxin and could probably be eaten safely, but birds don’t know that. Monarchs further south are probably toxic to birds.
According to the MSU Extension, there are about a dozen types of milkweed that are native to Michigan.