Perennial ( Asclepias syrica) Germ 14-21 days Fragrant and nectar abundant pink flowers along with the leaves are an important food source for many butterflies and insects. Flowers in midsummer followed by green pods which dry, opening up with fluffy seed heads. Spreads by seeds and underground rhizomes. Grows 3-4 feet. Hardy to zone 3-9. 40 seeds.