THE DETAILS: The first problem? The butterfly bush has been placed on a number of government and university invasive species lists because of its ability to spread easily and outcompete native plants. Originally from Asia, these plants have virtually no natural predators here, so they infest areas and crowd out native plants that provide food for native bugs, birds, and other animals. The second problem with the beloved bush? While it draws butterflies with its nectar, it does not supply butterfly larvae with food, which means they’ll have to expend time and energy finding another place to lay their eggs. So if you want the best for those butterflies that visit your garden, it’s good to have plants that offer not just the nectar, but also act as a host site. Especially since some of the plants that are better for butterflies are getting crowded out. “Many people think all plants are the same. But when invasive plants grow, they take up space native plants could occupy,” says Tallamy. “We’ve got to put the right ones back where they belong.”
WHAT IT MEANS: There’s more at stake here than butterflies. As more and more wild areas are lost to development, every green space left becomes increasing important. “Plants provide ecosystem services that keep us alive,” says Tallamy. They filter drinking water, prevent runoff and flooding, produce oxygen and sequester the greenhouse gas carbon dioxide, and help build topsoil. Native plants do all that while keeping our food web healthy. Right now, 30 percent of plants in most natural areas are invasive, which reduces the food supply for birds and insects by 30 percent, Tallamy explains.
You can attract butterflies, and help keep your local environment healthy at the same time. Here’s how:
Find better butterfly plants. If you already have a butterfly bush that you can’t part with, you can minimize it’s impact. Just mulch heavily around it, pull out any seedlings that spring up, and trim it back before the plant goes to seed so it doesn’t spread. To truly support butterfly life, plant a mix of things that serve as nectar sources and hosts for caterpillars. These include milkweed, Joe-Pye weed, goldenrod, and purple coneflower. Plants in the milkweed family are especially likely to attract monarchs. Contact your local native plant nursery for even more ideas. The best part? Native plants are not fussy and definitely require no synthetic chemicals or pesticides.
•Give them water. All that flying makes butterflies thirsty. Make sure a nearby mud puddle is kept damp, or get a shallow plate, fill it with sand, and then just keep it damp.
•Give them sun AND shade. Butterflies also need lots of sun, which you should already have somewhere in your yard, because most of the host and nectar plants require full or partial sun. Plant your butterfly garden near shade, though, so the butterflies have a place to cool off on very hot summer days. Trees are also important because butterflies like to hide on the underside of leaves for protection.
•Plant a colorful garden. Color loves company: Butterflies generally like bright colored plants; pink, purple, and red-lavender are favorites. Plant flowers with single petals instead of double because those are easier for the butterflies to access. And choose native plants, which hold more nectar than hybrid types.
•Avoid invaders.If you planted only native plants in your landscape, the ecological benefits would be enormous. But it’s not all or nothing; if you choose to include some non-native species, be sure to avoid invasive plants. Efforts to pull out these culprits cost various government agencies upwards of $23 billion a year. Invaders also bring in diseases that can kill native plants. So next time you head to a nursery, make sure your selections aren’t on the [http://www.invasive.org/] invasives list.
•Turn off the bug zapper. If you own a bug zapper, unplug it—for good. These devices kill just .02% of biting bugs, and take out thousands of beneficial bugs that backyard birds rely on to live.