Monarch Butterfly, Danaus plexippus
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. They are preyed upon by Stink bugs and Assassin bugs.
There are many kinds of milkweeds. We usually have three species in stock. They are easy to grow and look nice in a garden. Some of the reasons Monarch's are having problems is the removal of native Milkweed species and the introduction of other milkweed species into gardens.
The Monarch butterfly feeds on nectar form various flowers including milkweeds, Asclepias sp. In the picture below a monarch butterfly feeds on an Asclepias speciosa. This is a large milkweed that does very good in gardens. It has large showy flowers and large leaves.
They also like Butterfly mint, Monardella spp, below a monarch butterfly is sipping off an annual species. However, there are many perennial species that are very good in gardens. One of the most attractive ones is Monardella antonina, Butterfly Mint Bush, this species is very popular with butterflies.
Some other flowers that are used by the Monarch butterfly are; Salvia mellifera (Black Sage), Trichostema lanatum (Woolly Blue Curls), Agastache urticifolia (California Licorice Mint), Chilopsis linearis (Desert Willow), Helianthus gracilentus (Dwarf Sunflower), Encelia californica, Mahonia nevinii (a species related closely to Oregon Grape), Ribes aureum var. gracillimum (Golden Currant), Dichelostemma capitatum (Wild Hyacinth), Isomeris arborea (Bladder Pod), Lobelia dunnii (Blue Lobelia)and Cirsium occidentale var. venustum (Venus Thistle)