Butterfly bushes, those fluffy shrubs with purple flower clusters, have been a mainstay in many Connecticut gardens for more than 100 years. Now, ecosystem advocates say gardeners should consider planting alternatives that are native to the region.
A butterfly bush’s nectar will attract butterflies, according to the president of Pollinator Pathways, Donna Merrill. But when they arrive, they also immediately need a plant to lay eggs in, because many butterflies have a “very short time frame within the annual life cycle”.
While these plants are a great source of nectar for butterflies, they are not a source of food for the larvae.
"It [butterfly bush] just interrupts and disrupts the butterfly propagation within your garden and within your neighborhood and town,” she said. “You've basically created an ecological trap.”
“The caterpillars have to have the right plants to eat in order to complete their metamorphosis,” Uli Lorimer, Director of Horticulture for the Native Plant Trust, said.
Michelle Detweiler, an ecological planting designer for Pollinator Pathways, said the popular butterfly bush only offers nectar for mature butterflies.
"It doesn't provide for their caterpillars or any native caterpillar for that means," said Detweiler.
Detweiler recommends butterfly bushes be replaced with plants that can support caterpillars. She suggests any native milkweed, golden rods, asters, sunflowers and phlox.
She also recommends logging into the National Wildlife Federation website, which provides information on how to find the right native plant for your area.
Butterfly bushes will spread
Native plant advocates also say the other problem with butterfly bushes is how easily they will spread outside your yard.
Merrill said certain types of butterfly bushes can produce more than 40,000 seeds in one spike.
“So you absolutely do not want the butterfly bush to go to seed,” Merrill said.
The concern about butterfly bushes spreading in the environment prompted the landscape industry to develop species that are marketed as sterile, but Detweiler says they cannot be trusted.
“They will still be fertile to a certain extent and they will still likely self-seed. They can also revert to becoming fertile, so it's not a good solution,” Detweiler said.
Merrill advises anyone with a butterfly bush in their yard, if they aren’t ready to get rid of it and replace it, to cut off the flower as soon as it starts to wilt and die.
“They should be bagged and disposed of,” she said, like garbage. Do not compost cuttings.
Lorimer, who also sits on the Advisory Council for Pollinator Pathways, would like homeowners to garden not just for what pleases the human eye, but also for what feeds our wildlife.
