Milkweeds and Monarchs
A Little Good News
Authors: Ron Vanderhoff, Mike Evans and Bob Allen
Monarch butterflies are on the rebound in California. Early counts show a nice increase in the numbers this fall, in Orange County and around the state, compared to steadily declining tallies over the past several years. In 2020, the species was even considered for Endangered Species designation, an action that remains a real possibility.
But efforts to save the species just might be working; habitat preservation, reduction in the use of harmful pesticides and herbicides, and yes, native plant gardening which provides host plants for the caterpillars and nectar plants for the adults. The effects of wildfires, habitat loss, pathogens, climate change and a host of other factors might be somewhat mitigated by simply planting native butterfly plants in home landscapes.
We’re doing it! The numbers are better. In 2021, Tree of Life Nursery and Roger’s Gardens customers took home and planted almost 16,000 native milkweed plants consisting of three species. Other retailers added their share as well. Rogers Gardens even offered a milkweed exchange program: bring in an uprooted, tropical milkweed plant (not good for monarchs), and you got a free native milkweed in exchange (definitely good for monarchs). With other local nurseries added in, let’s put a best guess at 20,000 new native milkweed plants now in and around suburban Orange County.
And the results seem to be showing. Bob Allen, the Orange County Thanksgiving Monarch Count Coordinator, is finally reporting that monarchs again are showing up at their historical overwintering sites, right here in Orange County.
Each year for the past thirty, during the weeks surrounding Thanksgiving, monarchs are counted at the break of dawn on specific legacy trees along the California coast. These counts, from hundreds of locations, are then carefully tabulated to provide the most accurate data available on monarch numbers.
In Orange County, Bob and Ron have been busy visiting each of the fifteen or so overwintering sites and have found at least a few monarchs at most of them. A cluster of 300 in San Clemente, a cluster of 150 in Huntington Beach and smaller clusters and scattered individuals at other sites is encouraging. The numbers aren’t huge but it’s a substantial improvement over the one single overwintering monarch that was found in 2020, the three counted in 2019, or even the 56 or 68 in the two years prior.
As of this writing we have surveyed colonies in San Clemente, Capo Beach, Dana Point, Laguna Beach, Crystal Cove, Costa Mesa and Huntington Beach. We concluded the annual surveys on Sundaywill finish with a count this Sunday, Dec. 5 in Seal Beach. Including the San Clemente colony, which was located in late October, we will end up with about 500 overwintering adults this year, are far cry from just 25 years ago when almost 14,000 were counted in Orange County. But it is encouraging.
Our counts will be combined with other counts from throughout California and Northern Baja and tabulated by the Xerces Society, the leading Monarch and invertebrate conservation organization in the United States. Bob and Ron will be out again surveying the same colonies in January, assessing any changes in their numbers and getting a better understanding of their status.
Though we have no hard data regarding a correlation between new larval food plants in home gardens and the numbers of overwintering Monarchs, comparable results are being seen throughout California. Let’s hope for even more encouraging news at year’s end when the 2021 count will be complete.
This fall, you can still provide nectar for pollinators, including butterflies of all species by planting flowering natives, specifically butterfly host plants. You can also plant even more native milkweed next year, when the plants re-emerge from their winter dormancy.
Thank you to all the local gardeners and Monarch enthusiasts for spreading the word, planting locally native milkweeds and helping monarchs recover.
General Manager of Roger’s Gardens and Vice President of the CA Native Plant Society – OC.
President of Tree of Life Nursery in San Juan Capistrano, California’s largest native plant grower.
OC Monarch Count Coordinator, author of Wildflowers of OC and the Santa Ana Mts. and a professor of biological sciences.