Seeds from this Asclepias Hirtella Woodson Tall Green Milkweed can have stalks that are 3 to 4 inches tall. Leaves are opposite and very narrow and long. Leaf length is 4 to 6 inches and width is 2 to 3 inches. Flower cluster on the top of the plant only. Each cluster contains up to 50 individual flowers. Seed pods are long and skinny. Sap of this milkweed is not milky. They bloom during May through July. Hardy in zones 6 to 10. 4 to 6 weeks of stratification suggested for good germination.