- You will get 101+ Seeds of Sky Blue Aster Flower Seeds. - Seller Notes: “Symphyotrichum oolentangiense. U.S. Grown Seed. Tested 1/23-Germination 94%. Packed 1/23.”. - Planting Time: Perennial. - Soil Type: Chalk, Clay, Loam, Peat, Saline, Sand. - Life Cycle: Perennial. - USDA Hardiness Zone (°F): 4 (-30 to -20 °F). - Soil pH: Neutral. - Watering: Medium. - Sunlight: Partial Shade, Full Sun, Medium Sun. - Sky Blue Aster Seeds. This is medium (36") perennial prairie plant. It has intensely colored 1 1/4" blue flowers that bloom in late summer through fall. Asters go into high gear when most of the other plants are dying out or going to bed for the winter. They attract the later pollinators and add late season interest. It is a "behaved" aster, meaning it does not spread fast and out of control, so it can be an excellent addition to home gardens. Basically, a carefree, long lived native wildflower. 100+seeds per order. Thanks for looking! - Symphyotrichum oolentangiense. - Perennial. - Full sun/Part sun. - Spring, soil temp 65F+. - SOW-4 seeds per, 1/16"deep, about 18"apart. Keep moist. - Germination 14-21 Days. - Medium water. Light fertilizer. - Flowers are blue. Blooms August, September, October.