May 13, 2021

Tips for protecting monarchs

3 best management practices

WASHINGTON — Monarch butterflies are an important pollinator species experiencing declining populations.

According to the Environmental Protection Agency, threats include loss of breeding habitat, loss of overwintering habitat in Mexico, changes in weather patterns and other factors.

The EPA believes a holistic approach is needed for monarch conservation. This includes judicious use of herbicides, balancing weed management needs with monarch conservation needs.

Best-management practices are effective, common-sense practices that emphasize proper pesticide mixing, loading and application.

Best Management Practices

1. Avoid application of bee-toxic pesticides during bloom.

2. Make pesticide applications in the evening or at night when pollinators are not actively foraging.

3. Check wind conditions and other weather parameters prior to pesticide application.

“Specifically, things that people can do to protect monarch butterfly habitat when it comes to herbicides is to use herbicides efficiently and effectively,” said Amanda Pierce, biologist at EPA, during a webinar.

“What we mean by that is use a selective herbicide, so an herbicide that’s actually just targeting the weed that you’re interested in, or if you’re using a non-selective, broader herbicide, to use that in a selective manner to reduce the potential impact on milkweed plants.”

It’s important to always read and follow label directions on herbicides and pesticides.

For more information on best management practices, visit

Erica Quinlan

Field Editor