Plant of the Month: Goatsbeard
This month’s plant, goatsbeard, is now blooming along roadsides and in gardens around the Salish Sea. As summer arrives, it will be blooming higher into the foothills. I’ve noticed lots of it blooming along rural roads in the past week while I’ve been out bicycling here in Whatcom County.
Feathery plumes of creamy white blossoms extend from the stems of this tall perennial. Those plumes resemble the long whiskers of mountain goats, giving the plant its common name. Goatsbeard, Aruncus dioicus, is native to both the west coast and eastern North America, although there are different varieties on the two sides of the continent.
Many gardeners describe goatsbeard as similar to Astilbe, a genus with two native species in eastern North America and many more introduced and hybrid cultivars and varieties in cultivation. Both Aruncus and Astilbe are in the rose family. In the photograph above, white goatsbeard and a pink cultivar of astilbe are growing together in the University of British Columbia Botanical Garden, Vancouver.
Our native goatsbeard grows best in part shade and moist soil. That’s why it’s seen so often along roadsides and trails. It’s a showy plant when in bloom, standing 2-7 feet tall. Grown in the garden, it can form nice-sized clumps. Plant it in a woodland garden in rich soil. In northern areas it can take more sun as long as it gets sufficient moisture.
Goatsbeard is dioecious, meaning it has male and female flowers on separate plants. The male flowers are showier, the plumes of blossoms appearing thicker and more feathery.
Even when not in bloom, goatsbeard is an attractive perennial. It has large, pinnately divided leaves with toothed edges. Come autumn, the foliage turns a nice bronze.
Goatsbeard is available in the nursery trade or may be grown from seed. It can also be propagated by dividing large clumps, something best done with garden specimens rather than digging up plants from the wild. If you’re growing goatsbeard from seed, there’s no way to know whether you’re going to get girl or boy plants until they’re big enough to bloom so you’ll want to start several plants to get the ones you want. You’ll probably want to plant males for their showier blossoms and to avoid having seedlings pop up all over the place.
You can see more photos of goatsbeard on my PNW Flowers website.