Flat-topped White Aster

Doellingeria umbellata

Flat-topped white aster is the tall, dramatic aster for moist sites that blooms in August and September when monarchs and fall migrators are moving through. The flowers are arranged in broad, flat-topped corymbs -- hundreds of small white daisies with yellow centers arranged in a wide platform that butterflies can land and feed from for long stretches without moving. On warm September mornings, a stand of this plant can look like a butterfly convention in progress. At four to six feet, it reads as a structural back-of-border plant in moist gardens, pond margins, and rain garden edges. The foliage is clean and attractive all season, and the dried seed heads carry into fall as bird food. A high-value, underplanted species that deserves far more attention in designed landscapes.