Efforts to preserve monarch butterfly populations are sprouting in Lockeford.
Conservationists at the Lockeford Plant Materials Center, part of the U.S. Department of Agriculture’s Natural Resources Conservation Service, are growing experimental milkweed gardens. Their goal is to find out how to best grow and spread the flowering plant that monarch butterflies depend on for survival.
Each fall, monarchs travel from their summer habitat in the northern U.S. and Canada to winter homes in California and Mexico, stopping to eat, mate and lay eggs at patches of milkweed along the way. But fewer are coming every year.
The Xerces Society conducts annual Thanksgiving and New Year’s counts, along with sites in California and Mexico, where they have tracked the monarch butterfly populations for decades.
“In 1997, a total of 1.2 million monarchs were observed overwintering along the Pacific coast,” a statement from the Xerces Society said.
Just a few years earlier, in 1991, at least 200,000 of the stunning butterflies were counted at Pismo Beach alone.
That number has fallen drastically.
“In 2015, the number of monarchs was 292,674,” the Xerces Society reported.
During the 2018 Western Monarch Thanksgiving Count, the group found that the number of West Coast monarchs spending the winter in California had plunged to only 20,456 butterflies.
In response to the dwindling butterfly population, the Xerces Society has issued a call to action.
The group has banded together with the Lockeford Plant Materials Center to conduct research on the migratory patterns of the butterflies and their reliance on milkweed.
“Monarch butterflies require milkweed plants to lay their eggs on. They contain some toxins that accumulate into the caterpillar, to make them less attractive to bird species,” said Margaret Smither-Kopperl, manager of the Lockeford Plant Materials Center.
But those toxins can be harmful to cattle and other livestock, so most farmers do not grow the plant as a cover crop for their fields, she said.
According to the Xerces Society’s report, rampant pesticide use has also contributed to the loss of milkweed, which also serves as a food source for the monarchs.
The Lockeford Plant Materials Center has planted a test garden with three species of milkweed plants, to establish an ecosystem where the butterflies can congregate during their migration cycle.
Growing the plants turned out to be more challenging than expected.
“We had a hard time establishing the milkweed during the trial process, and we found that the Xerces Society also faced difficulties in establishing the plant,” Smither-Kopperl said.
It took a bit of trial and error to find out the best ways to cultivate each species, plant material agronomist Valerie Bullard said.
“We tried (planting the milkweed) by seed in the fall, and we tried with rhizomes, and we had three transplants that were planted at different times of the year, one during the fall, winter and spring,” she said. “We found that the rhizomes worked really well for one species of milkweed, but the others did not germinate at all.”
The center will replicate the growing trial of the milkweed plant four times in order to find the best strategies for growing the milkweed plants. Then, they’ll pass that information on to the Xerces Society so they can share the best methods for growing and transplanting milkweed, Bullard said.
Determining the best way to successfully transplant milkweed can help the Xerces Society distribute the plants to citizen scientists and home gardeners.
“Even a pot or two growing in your garden can help the monarchs,” Smither-Kopperl said.
The Lockeford center does not currently track the numbers of monarch butterflies that make the trek to their garden. However, they do have volunteer positions and internships available to citizen scientists eager to participate in tracking the monarch migration, growing milkweed, raising caterpillars, and more