The following is to continue the discussion started at the September Berkeley Garden Club meeting about the desirability of planting CA native milkweed for our diminishing population of Monarch butterflies:
According to the Las Pilitas Nursery, a CA native plant nursery in Santa Margarita, CA, “The Monarch butterfly larva feeds on milkweeds. Some of their favorites are the Monarch Milkweed, Asclepias eriocarpa and the Narrow Leaf Milkweed, Asclepias fascicularis. Milkweeds contain toxins that make the adult poisonous to birds and other predators. Most insects can eat the monarch without effect.” Also available locally, is Showy Milkweed, Asclepias speciosa. All the the above are nectar food for the butterfly and important food for the eggs, and resulting very hungry caterpillars of the Monarch.
Each of these CA native species die to the ground in winter, which urges the Monarch to migrate to their wintering grounds in places like Pacific Grove, the Big Sur coastline and Baja, California’s central valley. When we plant the non-native milkweeds, like Butterfly Weed, Aesclepias tuberosa, or Blood Flower, Aesclepias curassavica, both readily available in our local nurseries and also relished by the Monarch, we should cut them to the ground in late fall to prompt the Monarch on in their normal migratory patterns. When the Monarchs don’t migrate, they lay their eggs and the resulting winter larvae is more likely than the migratory Monarchs to face multiple threats and also become infected with the protozoan parasite Ophryocystis elektroscirrha [OE].
The more we know about our butterflies and beneficial insects, the smarter we will be about providing nurturing, safe habitats in our gardens. This coming month our speaker will be Kate Frey, author of The Bee-Friendly Garden, so our conversation about providing gardens that nurture life and beauty will continue at our October 17 meeting.