Aruncus dioicus (goatsbeard) is lighting up the shade right now. This perennial is about 2 metres (6 feet) tall. Unlike some of the subtle shade plants, goatsbeard grabs the attention, especially when its towering white flowers bloom.
The tall plumes are a cream colour that are very noticeable in the shadows. The long narrow blooms sway in the breeze, and give the plant a more delicate look at the top, than the solid foliage below.
The foliage is like a coarser version of an astilbe. It grows quickly in the spring, and forms a substantial clump. It can be 1.2 metres (4 feet) across. This perennial looks more like a shrub when it matures, growing rapidly from new sprouts every spring.
Goatsbeard is a great perennial for the back of a shady border, or in a corner. This healthy plant receives about an hour a day of direct light. It tolerates medium shade very well, but it is not as happy about deeper shade.
Another of my A. dioicus was planted in a darker corner under a willow. Whether from the deeper shade, or the competition with willow roots, it never bloomed, and only grew a half metre (a few feet). The branches were close together, like the stunted trees you find growing in alpine areas, a little krumholtz. I’ve moved it to a medium shade location last year, but it hasn’t caught up in height with my other goatsbeard, nor has it bloomed. I hope I haven’t permanently stunted it, from an impoverished start.
Aruncus dioicus blooms in the summer, when many of the shade perennials have quieted down. Mine blooms for about 2 to 3 weeks in July. I like this perennial because it adds height in the shade. There are fewer tall shade plants from which to chose. Another tall shade perennial, Actaea simplex (bugbane), formerly Cimicifuga, will be blooming late in the summer. What tall shade perennials do you grow?
I’ve written more about this perennial and the dwarf goatsbeard on another post.