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. 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. Thin to single best seedling. Use scissors to cut out unwanted sprouts. Height 36"- 48" tall x 18" wide. Medium water. Light fertilizer. Flowers are blue. Blooms August, September, October.