Native milkweeds are the required host plants for the monarch butterfly’s caterpillars (Xerces Society, 2025). These caterpillars exclusively feed on milkweed, making the plant a critical aspect of their life cycle. However, it is a common misconception that monarchs use milkweeds across their habitats year-round. In fact, planting milkweed at historic overwintering sites can negatively impact monarchs.
The VCRCD Restoration Team continues to restore historic monarch overwintering and breeding sites across Ventura County. Recently, the team planted a variety of native plants at Pleasant Valley Masonic Cemetery— a monarch overwintering habitat they have been enhancing since 2021. This overwintering site should be used by monarchs to rest and roost for the winter; however, previously planted native milkweed continues to disrupt this process. If milkweed is nearby, female monarchs will produce eggs to breed rather than conserving their resources to get them through winter. Additionally, native milkweed often drops its leaves in the fall, causing newly hatched caterpillars to lose their food supply. Fall and Winter blooming nectar plants should be planted instead of milkweed at these sites to fuel the butterfly during overwintering.
Unfortunately, the team found multiple caterpillars at this site, meaning female monarchs have begun breeding when they are not supposed to. The Restoration Team will relocate the caterpillars and transport the milkweed plants to one of our inland breeding sites where they will continue to feed caterpillars in the spring.
To learn more about the impacts of milkweed in overwintering sites and a monarch’s life cycle, click here.
Photo by David Dockter near the cemetery in October 2025. See more of his photos here.
