The leaves, blossoms, and seed pods are eaten by the Monarch butterfly. The blossoms are a host nectaring plant to all butterflies. The glycosides in the latex of native Butterfly Weed are not as toxic as other native milkweed species.

Common Milkweed leaves, blossoms, and seed pods are eaten by the Monarch caterpillar, however, many species of butterflies nectar on the flowers of this native plant. The plant's latex contains glycosides, making it toxic to animals. It is an aggressive rhizomatous spreader and best planted in a field and not in a flower border.

The leaves, blossoms and seed pods are larval food for the Monarch caterpillar. Many butterfly species nectar on the blooms of this native plant. Latex produced by the plant contains glycosides making the plant toxic to animals.

Tropical milkweed is grown in Maine as an annual and the leaves and blossoms provide food for late season Monarch caterpillars. It is non-native, and therefore not an ideal choice for growing in Maine butterfly gardens, but works well in a pot or planter on a deck if there is no space for a garden.