If you’re a New England gardener looking for a large-impact shade perennial that blooms in early summer, you can’t go wrong with Goat’s Beard (Aruncus dioicus). Perfect for a partly-shaded woodland edge, its creamy white flowers are especially striking contrasted with a darker background:
Native to the rich woods of Pennsylvania southward, Goat’s Beard grows quickly in spring from a woody crown, with flowering stems that can reach 6′ in moist soil. Flowering in late June in my zone 5b central Massachusetts garden, Goat’s Beard seems to do best with about half a day of morning sunshine. It usually takes a few years to get established, but once mature, it fills a good size area, so give it plenty of room.
Don’t confuse the native Goat’s Beard to the commonly planted Astilbe, which is also sometimes called Goatsbeard. Astilbe is much shorter than the native Aruncus, growing only about 2′.
Goat’s Beard is a good plant for New England habitat gardens…its flowers attract hordes of beneficial pollinating insects, and its long seed tassels persist well into winter. Don’t these winter seed stems look like a nice meal for birds?
Aruncus dioicus is dioecious, which means that there are male and female plants. Only the female plants produce the seed heads, and their flowers are slightly showier than the males, so plant several Goat’s Beard at a time to ensure that you have at least one female plant. Even if you are lucky enough to find this plant for sale in a nursery, you’ll probably get some blank stares if you ask what sex they are! In central MA, this plant is sometimes available at Bigelow Nurseries in Northborough as well as Garden in the Woods in Framingham. I also have them for sale during the season at Turkey Hill Brook Farm (Spencer, MA).