Smooth blue aster is another garden hero. Its superpower is the ability to bloom well after the first autumn frost, and grateful pollinators will frequent it on sunny October days when no other flowers are left. Smooth aster enjoys sun, shade, dry, moist...a true generalist. Leave it alone once it's established - too much extra water can make it very large! Prone to reseeding if you have a lot of bare ground, so cut off stalks after flowering if that doesn't appeal to you.