is milkweed a perennial
Milkweed perennials (Asclepias spp.) bear many small star-shaped flowers and produce a milky sap; they are named for this sap. The plants grow in U.S. Department of Agriculture hardiness zones 3 to 10 and bloom in summer, bearing their flowers in broad, flattened clusters at the branch tips. All varieties produce silky seeds within inflated seed pods. Milkweed thrives in a sunny location with sandy soil and offers benefits to insects.