Green Guide: Rhus spp.

The sumacs, members of the genus Rhus, provide a great example of plants that were once considered highway trash but are now more firmly rooted in the genre as a treasure.

Some Rhus make excellent landscape plants as long as they are used correctly. Most are about as bomb-proof as you will find in the plant kingdom. They exhibit tremendous adaptability – they’re tolerant of dry and poor soils, and seem to thrive on neglect. Ease of propagation (root or stem cutting depending on species), production and establishment are all major pluses for this group.

But they also offer outstanding foliage throughout the seasons. Some offer deep, glossy green throughout summer and all present a stunning fall foliage show.

But take heed, many Rhus are colonizers and tend to spread and form broad colonies. Most species are reasonable to manage in the landscape, but they require careful observation for and removal of spreading suckers. Rhus are great in naturalized sweeps and almost always work best when planted in multiples.

R. aromatic
The fragrant sumac is, to me, one of the great overlooked North American natives. In its wild form, the plant is large and rangy, growing 8-10 feet tall and wide. But some cultivars offer controlled and workable plants. In spring, male catkins emit a strong, spicy aroma. Deep, glossy green, trifoliate leaves emerge in late spring and remain in excellent shape all summer.

Fall foliage takes center stage with masses of rich reds, oranges and wine mix to create an amazing show.
‘Gro-Low’ maxes out at 2-3 feet tall and at least twice as wide. Use as a massing shrub for a great groundcover. I’ve used it to great effect in parking lot medians and other difficult sites.

R. chinensis
This large, typically tree-form species wins the prize for more aggressive spreader. Plants grow to 20 feet tall and wide, or larger. But they can occasionally make spectacular specimens. Large, creamy flower panicles in summer remain effective into the fall fruit show and can be quite elegant. Bright-green summer foliage often morphs to outstanding yellows, oranges and reds in fall.

Elwin Orton’s ‘September Beauty’ is aptly named with excellent vigor and a beautiful floral and fruit display. Use it in a lawn area where mowing is frequent to keep suckers at bay. Watch for verticillium wilt.

R. copallina
It typically grows 15 feet tall and is a suckering species. Summer leaves are brilliantly glossy, turning to fire-engine red in fall.

‘Lanham’s Purple’ offers deep-burgundy foliage.

Morton Arboretum’s ‘Morton’ is sold under the name Prairie Flame. It’s a compact, shorter grower and it tends more toward red and wine fall color.

R. glabra
Smooth sumac typically grows 10-15 feet tall, and this cut-leaved species isn’t as much of a spreader. Try ‘Laciniata’ for its red-orange fall color.

R. typhina
The staghorn sumac is the most common and well-known species. ‘Laciniata’ is the most common cultivar and offers nicely dissected leaves and a rich mixture of green, yellow, orange and red. ‘Bailtiger’ (Tiger Eyes) is a screaming yellow, cut-leafed form.

— Paul Cappiello, Yew Dell Gardens; www.yewdellgardens.org