- You will get 51+ Seeds of Orange Butterfly Weed Flower Seeds. - Seller Notes: “Asclepias tuberosa. U.S.Grown seed. Tested 1/23 - Germination 93%. Packed 1/23.”. - Soil Type: Poor soils, Clay, Loam, Peat, Sand. - Life Cycle: Perennial. - USDA Hardiness Zone (°F): 7 (0 to 10 °F). - Soil pH: Neutral. - Watering: Medium. - Sunlight: Full Sun. - Orange Butterfly Weed. American Native Wildflower. This 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 not enough wild milkweed for the babies to eat. Once established this plant requires very little care. Drought and heat tolerant. One plant of Orange Butterfly Weed will form a large clump by its spreading rhizomes. This happens the second season and beyond. Tough perennial. Some can live 5+ years. 50+ Quality seeds. - Some American Native Wildflower seeds need to go through a cold winter to germinate. This plant is one of them. They do this so the seed won’t sprout in fall, only to have the seedling not make it through a cold winter. I have stratified these seeds to simulate a cold winter(stratification) This raises the germination rate considerably. Thanks for looking!!. - Asclepias tuberosa. - Perennial. - Full sun. - Spring, soil temp 60F+. - SOW 1/4" deep, 6" apart. Keep moist. - Germinates in 14 - 30 days. - Medium water. Light organic fertilizer.