Brain Food: Milkweeds for Monarchs

Jun 15, 2017

Scientists have noticed a sharp population decline in monarch butterflies migrating between Mexico and Canada. Flagstaff entomologist Mike Wagner wants to know if growing more milkweed will boost their numbers. Milkweed is a pollinator plant for many insects and the only plant on which monarchs will lay their eggs. 

Regents Professor Emeritus and entomologist Michael Wagner with different varieties of native milkweeds growing in the Northern Arizona University Greenhouse.
Credit Bonnie Stevens


Scientists have noticed a sharp population decline in monarch butterflies migrating between Mexico and Canada. Flagstaff entomologist Mike Wagner wants to know if growing more milkweed will boost their numbers. Milkweed is a pollinator plant for many insects and the only plant on which monarchs will lay their eggs.

“So it’s kind of a magnet, if you will, a magnet for butterflies,” Wagner says.

There are at least 30 varieties of milkweed in Arizona. Wagner has enlisted the help of local master gardeners to grow them in their own gardens in hopes of attracting more monarchs.

“So, we’re trying to do what we call a citizen science project to get local gardeners help us by planting plant, different species of milkweeds in different areas of central and northern Arizona to see which of these grows best, which is present when the monarchs are present, and potentially increase the population of monarchs that come through,” Wagner says.

Master Gardener Susan Olberding volunteers at Flagstaff's Pioneer Museum where she plants native milkweeds for monarch butterflies. The milkweed also serves as an educational tool for visitors to understand the relationship between pollinators and plants.
Credit Bonnie Stevens

Susan Olberding is a master gardener in Flagstaff.

“I was involved in the project last year and planted the milkweed at my home in Fort Valley and it was just too cold for them. So, I thojguht this year I thought we’d try it here at the Pioneer Museum because it’s lower elevation, a little warmer nighttime temperatures,” Olberding says.

Olberding and others report their findings to Mike Wagner in exchange for milkweed plants. He hopes the project will create more habitat statewide for the traveling butterflies.