Plant Spotlight: Smooth Sumac and Staghorn Sumac

What It Is

Sumacs are plants from the genus Rhus that grow around the world, with over a dozen true sumac species in North America. Despite the name, poison sumac is included with species including poison oak and poison ivy in the Toxicodendron genus. Sumac’s dried, ground fruit is a common spice in Mediterranean and Middle Eastern cooking, and the dried berries can also be used to made a lemonade-like beverage.

There is significant variety in size and form in the genus, but Rhus glabra, smooth sumac, and Rhus typhina, staghorn sumac, are two of the larger forms that can be grown as small trees. Though they are nearly identical in appearance and growing conditions, Rhus glabra is native across North America, including the Spokane region, while Rhus typhina is native only to the eastern half of the continent. Both grow naturally as large, multi-stemmed shrubs forming large colonies, but a bit of yearly pruning will keep them trained into a tree form.

Rhus typhina's rust-colored seedheads persist through the winter for a striking visual display.

Why to Grow It

Smooth sumac and staghorn sumac are fantastic plants for four-season interest. In a garden setting, sumac’s bare lower trunks offer architectural interest in spring and summer, while its feathery compound leaves create a dense screen of green foliage. Fall and winter are its real time to shine, though. Large conical seedheads mature throughout the summer, arriving at a deep rust color by autumn.The contrast with the green foliage is stupendous, but even better is the brilliant orange-red fall color. Sumac is one of the first plants to change, making it easy to identify along roadsides and in its native habitat. After the leaves drop, the seedheads persist through the winter, offering a bright spot of color as well as important food for wildlife.

Where to Put It

Sumac is an excellent plant for naturalizing marginal areas, as it does well in extremely poor soils and is very drought tolerant. It can often be seen on steep hills or along the roadside, as it is also resistant to erosion and pollution. In a residential landscape, a single-trunked tree will grow to about 15’ high with a slightly wider spread. Sumac will take some shade, but prefers full sun, and has low water requirements. Because the foliage is massed towards the top of the plant, sumac can be complemented with low- to medium-height perennials and shrubs around it to provide a visual balance.

Plant Spotlight: Symphoricarpos Species

What It Is

Symphoricarpos is a genus of shrubs commonly known as snowberry or coralberry, depending on the color of the fruit. It is native throughout North America, with the species Symphoricarpos albus common throughout the Inland Northwest. Our native snowberry is easily recognizable in the autumn and winter for its dense clusters of white berries, which persist months after the leaves fall. Its delicate foliage and small pink flowers are attractive but inconspicuous. All varieties are fairly small shrubs, generally topping out at five feet high and wide.

This hybrid coralberry holds its bright berries well into winter.

Why to Grow It

As the name suggests, snowberry and coralberry are prized for their prominent berries. A variety of cultivars and hybrids have been bred by the floral industry for a spectrum of pink berry colors and longevity in cut arrangements. You can enjoy those improvements just as easily in your garden, where the berries can also provide a winter food source for songbirds. Snowberry is also an excellent plant for naturalizing areas and erosion control, as it slowly spreads to form thickets when left to its own devices. Regularly harvesting its berry-covered stems, however, is enough to keep it in check.

Where to Put It

Symphoricarpos should be planted in full sun to part shade. Native Symphoricarpos albus is quite drought-tolerant, but nursery cultivars do best with supplemental water in the summers. Snowberry is fairly unremarkable most of the year, so place it with other plants that will offer more dynamic interest through the spring and summer, then let it take center stage in the winter. If you plan to use the berries in flower arrangements, consider locating snowberry off a covered porch or other area where it can be easily accessed when snow begins to pile up.

Plant Spotlight: Thuja plicata

What It Is

Thuja plicata, the western red cedar, is an evergreen conifer native to the Pacific Northwest. In Washington, it grows mainly on the wetter west side of the state, but it also grows throughout North Idaho. In fact, North Idaho is home to a huge western red cedar thought to be the largest tree east of the Cascade-Sierra Crest. Although it can reach giant proportions in the wild, there are many nursery cultivars available with more restrained growth, and Thuja plicata is often included in the arborvitae group. Cedar is well known for its iconic scent, as well as its natural insect repellent and rot-resistant qualities, making it a popular choice of wood for building outdoors.

Why to Grow It

The flat, lacy needles of Thuja plicata provide year-round beauty, as well as excellent screening. It is a great conifer for partly shady spaces, and the fragrant foliage is a classic holiday decoration. If the tree is limbed up as it matures, it maintains its interest with shaggy red bark that weathers to gray. Western red cedar’s dense foliage also provides excellent shelter for songbirds and wildlife in the winter months.

Where to Put It

Western red cedar works well as a single specimen tree in the landscape, but its dense structure also makes it an excellent hedge. While it thrives in full sun in its native range, a little bit of shade is helpful for the hot, dry summers we get in the Spokane region, and it does well into partial shade. Providing it with plenty of water is also important here, especially for plants in full sun, and Thuja plicata can even tolerate wet, boggy soils.

Plant Spotlight: Tsuga Heterophylla

What it Is

Western hemlock's delicate evergreen foliage provides interest throughout the winter.

Western hemlock, Tsuga heterophylla, is the state tree of Washington, where it mostly grows in the Cascades and the Olympic Peninsula. It prefers shady, moist conditions and is not found native in Spokane County, but it does grow throughout the Idaho Panhandle. Trees in the wild can grow to 100’ high and 30’ wide, but are smaller in cultivation.

Why to Grow It

Western hemlock is an attractive conifer tree for shady spaces. Its small needles and cones offer delicate evergreen interest, and it is a good tree for attracting birds. There are only a few cultivars cultivars available currently, but Tsuga heterophylla’s superior resistance to the hemlock woolly adelgid makes it a more reliable choice than the widely grown Tsuga canadensis. The insect is steadily devastating hemlock populations throughout the Eastern US, but western hemlocks do not show the same mortality when infested.  

Where to Put It

At least partial shade is necessary for the western hemlock in the Spokane/Coeur D’Alene region, where our hot, dry summers can stress the tree. Northern and eastern exposures are preferred, and Tsuga heterophylla does well in moist soil, as long as it is well-draining. The lacy, evergreen foliage is a great addition to a woodland or shade garden. Its soft needles won’t poke or jab like many other conifers, making it a suitable choice next to patios or pathways, where people might brush against it.