Smooth Blue Aster (Symphyotrichum Leave) – an herbaceous perennial wildflower that blooms light blue flowers in late summer to early fall, with a long blooming season of over 4 weeks.  
 
Growth: Can grow 3 - 4 feet tall.
Light: Prefers full sun. The more sun, the larger & more blooms the plant can produce. 
Soil: Prefers sandy to clay loam with dry to medium moisture. 
Hardiness: Can be prone to powdery mildew but proper air flow and direct sunlight can avoid this. A favorite of deer and rabbits.  
Maintenance: Low maintenance. Just ensure air flow between plants to avoid fungus.
Benefits: Attracts pollinators, including Monarch butterflies, and is the host plant to the Pearl Crescent Butterfly.