ROSE / SWAMP MILKWEED. Perennial.U.S.Grown seed. MILKWEED is the primary food plant of monarch caterpillars. The monarch population has been decreasing by 50% a year for over ten years. The reason is no milkweed for the baby's to eat. Once established this plant requires very little care. Drought tolerant. One plant of Rose/Swamp Milkweed will form a large clump by its spreading rhizomes,which can be divided.This happens the second season and beyond. The lifespan of this perennial 4-5 years. 50+ Quality heirloom seeds. I keep all milkweed seeds at 41F to help speed up germination.Thank You! Asclepias incarnate. Full sun. Early spring, soil temp 40F+. SOW on surface. Press into soil 6"apart. Do not cover. Needs light to germinate. Keep moist. Germination 14-28 Days. Thin to 18". Height 36 - 60" x 18" Wide.