Non Invasive Milkweed. Asclepias purpurascens purple milkweed is uncommon with many butterfly gardeners but it is a great alternative due to its non invasive habit. Common milkweed asclepias syriaca.
Importance as a butterfly nectar source. Showy milkweed is the western version of common milkweed. Usda plants database as of november 15 2017.
Cordifolia which is better suited to the sierra foothills 2000 ft.
As with common milkweed showy milkweed can become very invasive in the garden. Some species of milkweed like common milkweed asclepias syriaca have a tendency to be more aggressive in garden settings or disturbed areas and thus have a reputation of being weedy. Though not as commonly offered for sale as other milkweeds purple milkweed is worth searching out for its deep purple showy flowers. The flowers attract a wide variety of nectar seeking insects.