Goat's Beard (Aruncus dioicus) brings dramatic, feathery plumes and a big, architectural presence to moist borders and woodland edges. You will get the best performance in consistently moist, fertile, organically rich soil. Place it in full sun to part shade; in hotter summer areas it appreciates afternoon shade, while in cooler climates it can take more sun as long as the soil never dries out.
At maturity this plant forms an upright, bushy clump about 36-72 inches tall, with bold, finely divided green foliage. In late spring to early summer, airy panicles of tiny creamy-white flowers rise above the leaves. Plants are dioecious (separate male and female plants); male plants often look showier in bloom, while female plants can hold attractive dried seed plumes later in the season if you leave the stalks in place.
Water regularly during establishment and mulch to keep roots cool and soil evenly damp. Because it can be slow to establish, give it time in the first couple of seasons and avoid letting it dry out. Divide in early spring or fall if the clump becomes crowded. Cut back stems after frost, or leave seed plumes for winter interest and trim in early spring. Use it as a specimen, in groups for a bold backdrop, or along streams, ponds, and rain-garden edges where the soil stays reliably moist.