Did you know that every year Monarch butterflies migrate from as far as Northern Canada up to 3,000 miles down to the mountains of Mexico, visiting the exact same trees as their ancestors? Each individual Monarch only lives long enough to make part of the trip and it’s unknown how the descendants follow the exact same paths and find the exact same trees four generations later. The mystery of migration of these beautiful orange Monarchs is just one question that fascinates the Garden’s lead Butterfly Expert, Nancy Weiss. Every summer, Nancy leads Butterfly Walks in the Garden to share her knowledge of these wonderful insects and how we can support them. A lifelong naturalist, Nancy has been involved with the Massachusetts Audubon Society, the Smithsonian, Nature Serve, and the Master Naturalists before coming to Botanical Garden of the Piedmont.

Just like Monarchs, Virginia’s other native butterflies are in need of help. To thrive, every type of butterfly needs two kinds of plants. “They need what people normally think of, the nectar plants, for the adult to get nectar sugars for energy to fly around. But for their eggs to attach to and then turn into tiny caterpillars and grow, they need often different plants called host plants.” For example, Virginia’s state insect, the Eastern Tiger Swallowtail, can be seen swooping around many different plants for nectar from spring to fall. However, their eggs must be laid on Tulip trees or Magnolia trees as these are the only plants that support their caterpillars’ growth. It’s hard to picture these butterflies flying overhead, high in the trees because they aren’t often visible there, but these trees are essential for their reproduction. Another example of a butterfly that requires trees is the Zebra Swallowtail, whose only host plant is the Pawpaw tree.

Not all butterflies attach their eggs to a specific leaf or stem. There are butterflies like the Great Spangled Frittaries who use the “bomb approach” with eggs. They’ll fly over the field of their required host plant, violets, and drop their eggs one by one all over the field of violets. Once the caterpillars hatch, they will immediately look for a violet to eat. So the approach may be different, but the need is the same: a specific host plant for each butterfly species. The bombing butterflies need a lot more of them! The problem is that many of the native plants needed for both supporting butterfly eggs and providing nectar to the adults are becoming more and more scarce.

The presence of the right host and nectar plants does not guarantee that the butterflies will thrive. Another danger butterflies face is invasive plants. Even when the host plants they need are present, butterflies can confuse a similar-looking invasive plant for a host and place their eggs in a hostile environment by mistake where the caterpillars are unable to live. Butterflies are also threatened by the use of insecticides such as Neonicotinoids. “Nearly 100% of field corn and over 60% of soy seeds are treated with these pesticides.(1)” The chemicals then spread to every part of the plant, the surrounding soil, and the surrounding water. This means that even the surrounding unsprayed wildflowers, including the milkweed necessary for Monarchs, can become toxic to pollinators.

Nancy’s advice for those beginning to connect with butterflies is to watch which ones are coming to your own garden or window. These are the ones with plant support already nearby. You can take a picture and use the free iNaturalist app, inaturalist.org, to help identify the species. Now, you may wonder if you are seeing a moth, instead of a butterfly. However, butterflies never fly at night, so if you spot a flying “butterfly” after dark you’ve glimpsed a moth. “Some moths do fly during the day, but you can always tell the difference by their antennae.” Butterfly antennae always have a small thickening at the end like a knob. Moths’ antennae are either just threads or look “very complicated, like old TV antennas.”

Some ways to start supporting butterflies include: providing their native host plants, avoiding Neonicotinoids, and providing water for butterflies to drink. If you put out a shallow basin with a wide edge and fill it with water, then put in a few rough rocks of different heights. It allows the butterflies to have landing spaces and access water on their journeys. Rocks of different heights will allow them to continue to reach the water as the level lowers. Of course, you can also come to Garden events or service days to learn more about stewarding the land to promote native plants and remove invasives. Watch the Garden’s calendar for this year’s Butterfly Walk dates with Nancy Weiss!

2026-2-27 interview with Nancy Weiss

• https://www.worldwildlife.org/news/stories/the-other-big-reason-monarchs-are-in-decline-neonicotinoid-pesticides/

About the Author:
Whitney Zhang is a nonprofit professional with a passion for nature and wildlife. Before coming to Botanical Garden of the piedmont she worked as a Children’s Librarian at JMRL and the Contra Costa public library system in California.