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: Ilex x meserveae

What It Is

Commonly called blue holly, Ilex x meserveae is a group of hybrid hollies originally bred by Kathleen Meserve of New York after World War II to feature showy foliage and berries while maintaining cold-hardiness for Northeast winters. Size varies depending on variety, but generally ranges between 6’-12’ high and wide.

Why to Grow It

When most of the landscape is dull and dormant in the winter, Ilex x meserveae puts on a show with its glossy leaves and clusters of red berries. The berries provide winter food for birds, adding to the interest.

Where to Put It

Ilex x meserveae needs full sun to part shade to thrive. It will mature to a large shrub, so take advantage of its evergreen foliage and showy berries to screen a boring wall or fence. It also works well as an evergreen hedge. Ilex x meserveae requires a medium amount of water and will need artificial irrigation in the Spokane/Coeur D’Alene climate during the summer.

Like all hollies, a male and female plant are each necessary for the female plant to produce berries. One male plant can pollinate several female plants, but it’s important to ensure that the varieties flower at the same time. Most cultivars, however, come with a male and female form that have been bred so that their bloom times align. The Berri-Magic line even includes a male and female plant in each container to ensure berry production.

Glossy evergreen leaves and red berries make this holly a winter showpiece.

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.