The blue wood aster, Symphyotrichum cordifolium, also called the heartleaf aster or common blue wood aster, is a blue fall-flowering perennial wildflower native to eastern North America.
It is an unusually durable plant, adapted both to moderate shade and dry urban conditions.
In the garden, it is especially valuable as a late-blooming wildflower providing a blue color at a time when few other flowers bloom in such vibrant color. It is also a prolific bloomer, producing dozens of small flowers which persist for many days.
Ecologically, it is also a powerhouse, supporting a variety of insects and birds. Because of its wind-dispersed seeds, planting this species in your garden can help restore and protect nearby wild areas as it spreads into the surroundings.