Monarch butterflies are amazing creatures. These strikingly colored, orange, white and black butterflies migrate up to three thousand miles every year in the fall to spend the winter roosting in large groups in areas where weather conditions are cool but remain above freezing; then they turn around and fly the same distance back to their summer breeding grounds in North America in the spring. That’s quite a feat for an insect that weighs on average only 2/100 of an ounce! Monarchs that spend the summers west of the Rocky Mountains winter in groves of trees along the central and southern California coast, while those from eastern North America journey all the way down to the forests of central Mexico each year.
Unfortunately, these beautiful butterflies are in trouble. Over the past twenty years, monarch populations have declined by over 90%. The biggest threat to the monarchs is loss of habitat. Logging of Mexican forests has reduced the extent of the butterflies’ overwintering sites, and in this country, modern agricultural practices and urban and suburban development have led to loss of important grasslands habitat and a sharp decline in the number of milkweed plants that are vital for monarch reproduction.
Why is milkweed so important? Like all butterflies and moths, monarchs go through a complete metamorphosis in the course of their life cycle. A monarch begins its life cycle as an egg laid on a milkweed plant, which hatches out into an eye-catching caterpillar adorned with bright yellow, black and white stripes. This caterpillar feeds exclusively on milkweed plants before changing into a chrysalis, to emerge 10-14 days later as an adult butterfly. Without milkweed plants for nourishment the caterpillar stage can’t survive, and there will be no adult butterflies. While the adult butterflies feed on the nectar from milkweed flowers, they also feed on nectar from a wide variety of other flowers, which provides them with energy they need to fuel their long migratory flights.
How can you help the beleaguered monarch butterfly? You can plant milkweed in your own garden and landscape and encourage your neighbors and community to plant milkweed as well, not only in gardens, but in parks, wildflower meadows, along roadways, in natural areas, and on farmlands. Various native species of milkweed are found across the country. While some are wildlings that are best suited to more naturalized landscape areas, there are some species of milkweed that fit nicely into more manicured garden areas.
One of the best garden additions is butterfly weed (Asclepias tuberosa). This easy care perennial will liven up your garden with large, flat-topped clusters of bright orange flowers all summer long on 1-3 foot tall plants. All it asks is full sun and well-drained soil. Once established, butterfly weed is quite drought tolerant. Native to the eastern and southern U.S., besides feeding monarch caterpillars, its flowers provide nectar source for many other species of butterflies. A great choice for a prairie or meadow planting, it pairs nicely with other natives like purple coneflower, asters, and ornamental grasses. ‘Hello Yellow’ is a yellow flowered cultivar. Butterfly weed is adapted to USDA Zones 4-9.
Swamp milkweed (Asclepias incarnata) grows naturally in swamps (hence the name), but it also does well in garden settings in full sun, adapting well to soils with average moisture. A native of the eastern U.S., this milkweed is a robust plant reaching 3-5 feet tall and producing clusters of fragrant pink or mauve flowers through the summer. As with all milkweeds, it will feed monarch caterpillars and attract many species of butterflies. ‘Ice Ballet’ is a white flowered cultivar. Swamp milkweed is adapted to USDA Zones 3-9.
Both butterfly weed and swamp milkweed are easily grown from seed, and are the two species most commonly offered as plants in the perennials section of garden centers and nurseries, as they are the species most adaptable to general garden culture. But there are over 100 native milkweed species that thrive in a variety of climates and growing conditions. Common milkweed (Asclepias syriaca) is one of the most familiar, growing natively in most of the eastern and central U.S. and Canada, but other species are found in just about every region of the country. Here are suggestions for a dozen of the most ornamental native milkweeds from the National Wildlife Federation.
Other Ways to Help Monarch Butterflies
- Plant a variety of flowering plants in your garden so there are blooms from spring to fall to provide nectar for adult butterflies.
- Don’t use pesticides harmful to butterflies and their caterpillars in your gardens and landscape.
- Support actions to protect native grasslands.
- Encourage habitat restoration with community-wide plantings of wildlife corridors that include native milkweeds and nectar-producing plants.
- Support organizations that are working to help monarch butterflies, including Monarch Watch, the Xerces Society for Invertebrate Conservation, and the National Wildlife Federation’s Garden for Wildlife Program.