Plant a milkweed, save a monarch

Monarch butterflies need you. Or, rather, they need to hang out on your milkweed plants.

Those fluttery orange-and-black summertime visitors make an astounding journey from the mountain forests of central Mexico. And when they get here, says Alan Branhagen, Powell Gardens’ horticulture director, they’re interested in only one thing: milkweed.

In one of nature’s intricate plot devices, migratory monarchs lay their eggs exclusively on various species of milkweeds.

The caterpillars then eat the leaves and other plant parts to take in toxins, which make the resulting butterflies nasty-tasting or poisonous to many predators.

The monarch’s bright colors — some animals prefer camouflage — are nature’s way of alerting hungry birds and insects that the butterflies have a secret weapon.

The system works, Branhagen says, but it requires milkweed.

“Put the caterpillars on parsley, say, and they’re going to die,” he says. “They can’t ingest it.”

Don’t have milkweed? As part of its annual Festival of Butterflies, the botanical garden east of Kansas City is selling several milkweed varieties, starting at $8, and asking visitors to plant them in their yards or in containers.

Migratory monarchs are struggling because of habitat loss. Land development and herbicide use, among other factors, have taken a toll on the milkweed and nectar plants they need.

“We want to focus on what we can do to help mitigate this,” Branhagen says. “Monarchs have lost 50 percent of that habitat in the past few years. That’s a big blow for them finding enough food to raise the next generation on.”

The tropical milkweeds get bushy, a great attribute for a host plant. But they can’t survive the winter here and are best suited to containers on the patio, Branhagen says.

Several native, perennial plants are good choices for area yards and gardens, he says. The swamp milkweed has pink fragrant flowers and, as its name suggests, prefers wet areas. Orange or butterfly milkweed makes orange flowers and does well in dry areas.

“If you have a spot where it’s tough to grow anything, the butterfly milkweed will probably be happy there,” Branhagen says.

And common milkweed is an excellent monarch host, though it sends out underground stems for spreading, which some gardeners don’t like, Branhagen says.

During Powell’s recent butterfly count, part of the nationwide count sponsored by the North American Butterfly Association, 16 monarchs were spotted at the botanical garden. That’s about half of the annual average for the past 12 years at the garden and well below the high count of 103 in 2005.

Representatives from Monarch Watch, an education and research program based at the University of Kansas, will show festival visitors how monarchs are tagged and provide information about ways to support the species.

“This really special migratory population is like no other butterfly on Earth,” Branhagen says, “so special, we hate to lose it. I’ve been interested in butterflies since I was 5. It’s a shock to be witnessing what we’re witnessing.”

This story was originally published August 1, 2014 at 7:00 AM with the headline "Plant a milkweed, save a monarch."