Attracting Monarch Butterflies To Your Garden

Brenda Reed
Adams County Master Gardener

As warm weather arrives, one of the fascinating possibilities to consider is turning your garden into a home for pollinators, those wee garden visitors who help our plants flourish by spreading pollen from plant to plant. Let's explore how we can host Monarch butterflies, pollinators that are both beautiful and beneficial, as well as fun to watch.

The Monarch butterfly (Danaus plexippus) is easily recognizable by its orange and black wings. These amazing insects make a journey of up to 2,800 miles to Mexico where they overwinter away from the cold northern climates. Before they can make that journey, however, they go through a transformation which we can observe in our own backyards if we have the right plants for them.

Monarchs lay their eggs on milkweed plants since milkweed is the only thing the larvae (caterpillars) will eat. Essentially, without milkweed, we don't have Monarchs. Here in Pennsylvania, there are 11 native milkweeds that can be planted, such as the aptly named Asclepias tuberosa (Butterfly weed), Asclepias incarnata (swamp milkweed) and Asclepias syriaca (common milkweed). After hatching from their egg cases, the caterpillars eat the milkweed leaves for about two weeks until they are about two inches long.

Milkweed produces a toxin which keeps animals from eating Monarchs, but they have developed immunity to this toxin. This benefits Monarchs because the more the caterpillars eat, the more toxins build up in their bodies, making them taste bad to birds and other animals.

The next stage in a Monarch's life cycle is one we probably remember from our childhood: metamorphosis. The caterpillar will turn itself into a chrysalis, where it will remain for about two weeks. While in the chrysalis, the yellow, white, and black caterpillar transforms into the orange, white, and black butterfly before emerging to begin its next life stage.

While the Monarch caterpillar only eats milkweed, the newly emerged Monarch butterfly eats nectar which is shares with other butterflies from a variety of flowers, shrubs, and trees. Ideally, we want to provide a continuous source of food for the butterflies from spring through fall. Blossom colors matter since butterflies prefer red, purple, yellow, orange, and pink. Some plants which butterflies are especially attracted to are Echinacae purpurea (purple coneflower), Rudbeckia (black-eyed Susan), Eupatorium spp. (Joe Pye weed), Solidago spp. (goldenrod), zinnias, and asters. A bonus is that these plants also attract other pollinators such as bumble bees and honeybees.

Herbs are also attractive to butterflies. One example is the black swallowtail butterfly, which enjoys both parsley and dill. Shrubs and trees such as the spicebush, hibiscus, and willow are also popular with different butterflies.

When planning a garden to attract butterflies, consider planting in areas that get full to partial sun. Butterflies also like to have a place to bask safely in the sun, so having a couple larger of rocks for them to rest on is a great addition to the setting. A source of water is also appreciated.

Plant flowers in clusters instead of single plants. Pollinators will be more attracted to the area and more likely to visit the garden to enjoy the nectar. Some plants, such as Rudbeckia (black-eyed Susan), will self-seed once the plant is established. Butterfly weed is a perennial which will grow each spring from its tubers and produce seed pods that can be sown in the fall to come up in the spring, expanding your garden or giving you seeds to share with friends and family.

Last year after planting butterfly weed in my garden, I experienced first-hand the Monarch's life cycle. As the milkweed grew from freshly planted tubers, I began to see several Monarch caterpillars on the leaves. Eventually, I couldn't find the caterpillars anymore and discovered a chrysalis hanging on a nearby wood beam. After checking the chrysalis daily, one morning I spotted the freshly emerged Monarch butterfly. Watching the process in real-time has motivated me to expand my pollinator garden and attract more monarchs as well as other butterflies.

For several years, Master Gardeners with Penn State Extension have studied the various pollinators, including Monarchs, by counting those that visit the test gardens planted with four goldenrod varieties and Joe Pye weed. The study ended last fall and has given Master Gardeners an appreciation for the variety of pollinators and other insects that visit gardens state-wide.

Herbicides and pesticides can kill caterpillars and butterflies, along with their food source, so these products should be avoided. Increased usage of herbicides is not helping the Monarch population as we are losing milkweed. Local gardeners can help by planting varieties of this plant, vital to Monarchs.

Monarchs are being watched for possible inclusion on the Endangered Species List because of their recent decline in population. If everyone provides areas for these pollinators to thrive while reducing the use of herbicides and pesticides, we can turn back the hands of time and expand the numbers of Monarchs for future generations to enjoy.

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