Contributed by Lois Ports for the Bristlecone Audubon Chapter

Many people may consider the milkweed a weed and remove it from their gardens and property.  Yet the reason for planting and nurturing milkweed flies by in summer and is a favorite of many: monarch butterflies.

Milkweed is often found growing along roadsides and ditch banks.  Beneath its dull, gray-green exterior, milkweed is full of surprises. Inside the plant is a sticky white sap that contain several glucosidic substances called cardenolides that are toxic. It is most dangerous during the active growing season. Several species of milkweed are poisonous to range animals. The bitter taste warns away many of the animals and insects that try to eat its tender leaves. Certain insects, including monarch butterfly larvae, are immune to the toxin.

Adult monarch butterflies typically lay a single egg under a leaf near the top of the milkweed, its host plant. The eggs are about the size of a pin head and will hatch about four days after they were laid. The growing milkweed plant provides food and shelter for the larvae (caterpillar). The larvae will eat the leaves of the plant. It will take about 14 days for the caterpillar to mature and form its chrysalis.

The red milkweed beetle also utilizes the milkweed for its host plant. They also obtain some protection by incorporating toxins from the plant into their bodies. The beetle can become a problem for gardeners trying to establish milkweed in their gardens. The distinctive bold coloring of both the monarch and the red milkweed beetle advertise their inedibility.

Historically, the milkweed plant was valuable when grown for its medicinal properties. It caused an increase in perspiration which would help reduce fever. During World War II the silky material attached to its numerous seeds was used for filling in lifejackets and flight suits. Seeds are contained in an attractive pod that bursts and sends seeds drifting through the air, borne by wind.

Populations of the monarch have plummeted by approximately 90 percent in just the last two decades. You can easily grow milkweed plants to attract the monarch and other flying creatures to your garden. Plant seeds of the milkweed plant indoors or directly sow outside after danger of frost has passed and soil has warmed. If the appearance of the plant is too weedy for your taste, grow milkweed plants in a hidden but sunny corner or at the back of a border.

If you are interested in learning more about both the flora and fauna of our area you can send an email to to be put on our newsletter mailing list or find us on Facebook under Bristlecone Audubon Chapter.