- You will get 101+ Seeds of Bloodflower Milkweed Flower Seeds. - Seller Notes: “Asclepias curassavica. U.S. Grown seed. Tested 1/23-Germination 94%. Packed 1/23.”. - Planting Time: 10 Weeks. - Soil Type: Poor soils, Clay, Loam, Peat, Sand. - Life Cycle: Annual. - Soil pH: Neutral. - Watering: Light. - Sunlight: Full Sun. - Bloodflower Milkweed aka Tropical Milkweed, Silkweed. This milkweed is originally from central America, Mexico and the southwest. It won't survive freezing temps. It's usually grown as an annual. Milkweed is the primary food plant of the monarch butterfly 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. Does well in containers. 100+ Quality heirloom seeds. - Asclepias curassavica. - Annual. - Full sun. - Spring, soil temp 68F+. - SOW on surface. Press into soil 8"apart. Do not cover. Needs light to germinate. Keep moist - germination 14-28 days. - Medium water. - Flowers are red. Blooms late summer, early fall.