Whorled Milkweed for Monarchs (Asclepias verticillata) 100 Certified Pure Live Seed, True Native seed FREE SHIPPING Number of seed is Pure Live Seed, not bulk Species is US Native, not introduced alien We grow the seed so we control the quality A small 12" to 24" tall native perennial milkweed with white to green flower heads on mostly single stems. It flowers from June to September, tolerates part shade, and accepts dry to moist soils.