They’re gorgeous, but they actually do more harm than good.
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If someone took 75% of your food away, you wouldn’t be a happy camper. But when you grow invasive butterfly bushes and other plants that provide only nectar, that’s what you’re doing to birds and butterflies in your own backyard.
A leading wildlife ecologist wants you to think about your property — no matter how big or small — as an important link in your local ecosystem. Each plant you include in your garden affect the local food web, even the beautiful, seemingly harmless butterfly bush.
Doug Tallamy, PhD, professor and chair of entomology and wildlife ecology at the University of Delaware, revealed three hard truths about butterfly bush — and why you should stop planting them at home.
1. Butterfly Bush Doesn’t Stay In Your Yard
Butterfly bush is an invasive plant, meaning it crowds out beneficial plants that have naturally grown in your community for centuries. This species originally from Asia readily takes over space where native North American plants would normally thrive. In fact, Buddleja davidii (the scientific name for butterfly bush) has certain traits that make it invasive in most environments.
“I hear the ‘it’s invasive here, but not over there’ argument a lot,” says Tallamy. “While it is invasive in many parts of the U.S., what’s really important is that the plant has the ability to be invasive almost anywhere. If it’s not in some place, chances are good it will be [at some point].”
Beyond backyards, the plants spread to important ecosystems and protected areas. There’s clear documentation of aggressive butterfly bush invasions in wildlife habitats.
“People who say butterfly bush doesn’t move around are in the denial stage,” Tallamy says. “Butterfly bush just doesn’t stay where we plant it.”
2. Butterfly Bush Doesn’t Really Benefit Butterflies
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There’s no denying that butterfly bush’s long, narrow tufts of flowers look beautiful. And like many flowering plants, it supplies lots of nectar. But when it’s the only species you grow for butterflies, you’re not going to have butterflies anymore, Tallamy warns.
These insects also require proper host plants so they can reproduce. Their larval offspring have to feed on the leaves of native species like butterfly weed, other milkweeds, joe-pye weed, and oak trees.
“People rationalize their perceived need for butterfly bush because they think it helps butterflies,” Tallamy says. “What they really want is a pretty plant in their yard.”
3. Butterfly Bush Contributes to the Collapse of Food Webs
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Here’s the harsh truth: Planting non-native plants like butterfly bush in your yard actually makes it harder for the butterflies and birds in your neighborhood to survive.
For instance, if you want chickadees to breed in your yard, you need plants that can support the 6,000 to 9,000 caterpillars the birds need during the 16 days they feed their young.
“If you don’t have that, the plant-caterpillar-chickadee food web stops,” Tallamy explains. “If you plant butterfly bush, and not native [species], then right away you’re removing at least 75% of the food that is supporting the biodiversity that’s out there.”
And these critters need all the help they can get.