Monarch butterfly numbers drop as threats grow
U.S. butterfly populations drop 22% in 20 years. Learn how planting native flowers can help monarchs. Start your pollinator garden today.
Butterfly populations across the U.S. have declined 22% over the past two decades, according to a new study published in Science magazine. Monarch butterflies have been hit especially hard, with the latest Western Monarch Count recording just 9,119 individuals — a 96% drop from last year’s 233,394.
Scientists cite habitat loss, pesticide use and climate change as leading factors. The U.S. Fish and Wildlife Service has proposed listing the monarch butterfly as a threatened species under the Endangered Species Act.
The Xerces Society reports an 80% decline in the eastern monarch population and a 95% decline in the western population since the 1980s. The eastern monarchs’ overwintering grounds in Mexico now span just 2.2 acres, compared to 45 acres in the late 1990s.
Monarchs rely on milkweed and nectar-rich flowers during their multi-generational migration. Urbanization and industrial agriculture have reduced these habitats, leaving gaps in migratory pathways.
For greenhouse growers and horticulture professionals, the trend underscores the importance of growing and promoting native plants like milkweed, asters, monarda and liatris to support pollinators. Even small-scale plantings in containers or roadside strips can make a difference.
“We are at a critical moment for monarchs and pollinators,” said partnership cultivator Tabar Gifford of American Meadows. “Every flower, every wildflower patch and every pesticide-free yard contributes to the recovery of monarch populations.”
Experts recommend avoiding pesticides, planting native species and encouraging community action to restore pollinator habitats.