Much of the monarchs butterflys’ food source is being destroyed by drought and spraying along roadways here in California and along the Central Coast. Gardeners want to help by planting milkweed (the host plant of the monarch) in their gardens. Before you plant milkweed seeds or seedlings, know which variety is best to feed monarchs. There are varying opinions on this subject. Native milkweed is considered invasive in some areas. But contained in our gardens, native milkweed is not likely to present an “invasion” problem.
Some scientists recommend planting only native milkweed in California gardens like; Asclepias californica (California milkweed), Asclepias cordifolia (purple or heartleaf milkweed), Asclepias fascicularis (narrow-leaved milkweed), and Asclepias speciosa (showy milkweed). They believe exotic (non-native) milkweeds may cause some monarchs to loiter and avoid migrating and become infected with harmful parasites. Because non-native milkweeds are perennial and don’t die back, they tend to pass parasites on to monarchs more readily.
The loveliest of the California native milkweed (Asclepias speciosa) is call ‘Showy’. Its blossoms are carnation-scented, a rosy mauve. Monarchs, however, seem to prefer “showy’s” homelier stepsister, the narrow-leafed milkweed (fascicularis). Hide its rather plain looks behind native irises or shrubs in your garden.
If you have planted a non-native species of perennial milkweed and REALLY want to keep it, cut it to the ground several times a year. This keeps it healthy and helps to kill the parasites that infect the monarch. “Going native”, of course, is always safer.
For information and pictures of the California milkweed, go the Xeres website. You’ll be inspired!