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Helping Monarch Butterflies Reach New Heights

monarch butterfly-home pageThe monarch butterfly is a captivating and storied pollinator. Their dramatic and seemingly fragile wings of orange-and-black can nevertheless carry the butterflies on migratory voyages hundreds of miles from their birthplace. Monarchs live and perform pollinator services throughout southern Canada and the continental United States before commencing their multigenerational migrations to Mexico or coastal California to overwinter. But almost anywhere they are found, and regardless of where they overwinter, these butterflies are suffering sharp declines in numbers due to loss of habitat.

Because monarch butterflies are always on the move, they need to have the right plants at the right time along their migration route. Caterpillars rely on milkweed for food, and adult butterflies rely on the flowers from high-quality nectar plants to fuel their flight.

It is because of this dependency on milkweed that NRCS California is teaming up with the Xerces Society and Hedgerow Farms to launch a new study at the NRCS’ Lockeford Plant Materials Center (PMC) near Stockton, Calif. Over the next three years, these partners will test plant-establishment methods, and three different varieties of milkweed plants, to help create a series of recommendations for farmers and landowners to help repopulate milkweed across California’s landscape.

monarch_caterpillar“We know that the western monarch butterfly has experienced an estimated decline of 74 percent, and milkweed continues to disappear from our landscape,” said Jessa Cruz, Xerces Society partner biologist. “This project aims to help reestablish milkweed plants across the landscape, and provide recommendations for farmers and landowners.”

A Monarch caterpillar (left) snacks on narrow leaf milkweed. The leaves of milkweed are a critical food source in the life cycle of Monarchs.

The Lockeford PMC is in the middle of California’s Central Valley, an important migration route for western monarch butterflies, where perennial milkweed has been lost due to agriculture and development.  The western monarch butterfly is unique—choosing to overwinter on the California coast rather than heading to Michoacan caves in Mexico like its eastern cousins. 

“Establishing milkweed can be quite tricky,” said Margaret Smither-Kopperl, manager of the Lockeford PMC and a botanist. “But it’s extremely important to our efforts to aid western monarchs, especially here in the Central Valley where our PMC is located.”

The study will officially launch at the end of June 2017. It will begin by solarization of the planting site, using clear plastic tarping, to kill off any competing weeds and their seeds. Then in the fall, a succession of seeds, rhizomes and transplants from three different milkweed varieties will be planted in time for winter rainfall.

“The final goal of the study will be to establish a set of recommendations that farmers and landowners can utilize to establish milkweed in their fields and neighborhoods to help monarch populations rebound,” added Smither-Kopperl.