- You will get 100+ Seeds of Smooth Blue Aster Flower Seeds. - Seller Notes: “Symphyotrichum laeve. U.S. Grown Seed. Tested 1/23-Germination 93%. 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. - Smooth Blue Aster Seeds. This is medium (36"-48") perennial prairie plant that is named for its smooth leaves, somewhat unique in the world of asters. 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 laeve. - 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.