Symphyotrichum novae-angliae (New England aster)

Gorgeous purple flowers in September. Butterfly magnet. The large plant tends to sprawl, so give it room in a sunny meadow setting. Alternatively, you can cut it down in early June and it will grow back lower and bushier. Great paired with goldenrod for a fall show of color. New England aster grows to 4' in full sun and average to high moisture. Although deer will munch it, once it's established it can handle the pruning. Give it protection the first year.