Want butterflies? Learn to love caterpillars, too

By Debbie Arrington
With great intentions, a newbie gardening friend planted the biggest, showiest Showy Milkweeds she could find. She wanted to help monarch butterflies, the beleaguered species that migrates from Mexico to California. Monarchs love Showy Milkweeds and she hoped, like many gardeners, to attract some of these endangered beauties to her backyard.
And magically, the monarchs arrived. After their long migration, they somehow found these suburban flowers and made themselves right at home in her small garden.
"Now I've got a problem," she complained. "Something is eating the milkweed!"
Congratulations, I said. You've got a monarch nursery. 

Milkweeds (especially Asclepias speciosa, the Showy Milkweed) are both a "host plant" as well as a "nectar plant" for monarchs. Adult butterflies sip nectar from many kinds of flowers. But monarchs are particular about where they lay their eggs. They need a host plant, preferably milkweed, where their newly hatched caterpillars can have a ready and abundant food source.
"Host plants" are meant to be eaten. Remember that when planting a butterfly garden. It's got to be a no-pesticide zone. 

Awhile back, a reader called me for advice on her passionflower vine. I asked her if she had seen any of the bright orange fritillary butterflies that gravitate to that vine's unusual purple flowers. She had. While the butterflies were lovely, she was concerned about something else.
"The plant is covered with worms; they're eating holes in the leaves," she said. "What can I spray on it to kill these bugs?"
Nothing! Those are the fritillary caterpillars, and the passionvine was doing its job as a home to these hungry babies. 

In butterfly gardening, the goal is to attract beneficial insects, not kill them.
I admit I have destroyed (by hand) my share of cabbage white caterpillars and tomato worms in my vegetable garden. But the flower garden is for the bees and butterflies; caterpillars get a pass.
Butterfly lovers can't be perfectionists. If gardeners want to help monarchs and other pollinators, we need to accept some chewed-up foliage to go along with all the butterfly-friendly flowers. 

A good butterfly garden is bound to have some ragged edges. Holes in leaves and other proof of voracious appetites are signs of success. It can mean caterpillars growing strong.
Yes, they are creepy, crawly eating machines, but they are the next generation of butterflies. They're also a major food source for songbirds, who feed caterpillars to their young. More caterpillars mean more songbirds, too.
Focus on the flowers; the leaves will grow back.

(For more information on butterflies, check out Art Shapiro's excellent website at http://butterfly.ucdavis.edu/butterfly. The monarch image is courtesy his site, credit Erik Runquist. Monarch caterpillar and milkweed photos courtesy Cheryl Parry Rose.)