Balsam fir may be the Christmas tree of choice, a symbol of life in the dead of winter, but a common landscape tree and woodland native, the arborvitae — the “tree of life” — also offers welcome greenery in the outdoor frozen world. A common tree for framing landscapes and a common shrub for foundation plantings, arborvitae still seems special despite its prevalence around homes.

 

Native throughout the Northeast, Thuja occidentalis is widely adaptable. It can grow on dry, alkaline soils and by wet, acidic bogs (preferring the alkaline, however), reaching 10 feet in width and 30 feet in height. It is adapted to zones 3 to 7 and to full sun or partial shade.

 

Native trees grow slowly and are long-lived (sometimes living for centuries), while some cultivars, such as ‘Techny’ and ‘Nigra,’ are more contained, growing to half to two-thirds the size of the species and holding their green color better in winter than some. These are good choices for privacy screens and windbreaks.

 

The flattened, scaly leaves are handsome not only in the landscape but combined with contrasting evergreen textures, especially that of white pine, in holiday swags.

 

The trees are also attractive to white-tailed deer, which browse the foliage and use the canopy for shelter in winter. If you don’t want to attract deer, consider ‘Spring Grove’ arborvitae. Plants Unlimited says that this fast-growing, pyramidal-shaped cultivar of Thuja plicata is resistant to deer browsing.

 

Other mammals, including snowshoe hares and porcupines, browse on arborvitae foliage, and birds, moose and black bear use the tree for shelter. According to the University of Maine, “Pileated woodpeckers feed on the carpenter ants that, in turn, nest in and feed on the heartwood.” I sometimes see various birds taking shelter in the ‘Globe’ arborvitae, a rounded shrub, near our birdfeeder.

 

The reddish-brown bark of arborvitae is among its attractive features. If trees become too large for a landscape, one solution is to remove the bottom branches, revealing the handsome bark and creating a woodland setting. Most trees have single trunks, but some develop multiple trunks that emerge at right angles to the main trunk and then bend gracefully upward. These shapes can look interesting or awkward in the landscape, depending on the particular tree. Multiple trunks can hold so much snow and ice that they break.

 

To avoid multiple trunks, prune them out as soon as you notice them developing. To lightly trim an arborvitae to fit your landscape, see the 2-minute video at finegardening.com/how-to/videos/pruning-conifers-size-control.aspx.

 

You may also want to prune arborvitae to control their height; i.e., to encourage them to be shorter and wider rather than tall and narrow. Do this in late spring.

 

If an arborvitae does become too large or misshapen for a landscape, it can be cut down for its fragrant, durable, rot-resistant wood, which is used for boxes, shingles, posts, boats, and more.

 

The botanist and herbalist Dr. James Duke has an interesting page on arborvitae at hort.purdue.edu/newcrop/duke_energy/Thuja_occidentalis.html, where he notes historical uses of the vitamin C-rich foliage and of the essential oil, with warnings about potential toxicity. Others note that certain concentrations of thujone in the oil distilled from arborvitae can be a neurotoxin or may lead to abortion, and that the oil can kill ticks, fleas, bedbugs and other pests. That’s the flip side of the tree of life. A good review of the usefulness and potential dangers of medicinal products made from arborvitae appears at http://ecam.oxfordjournals.org/cgi/content/full/2/1/69.

 

Jean English lives in Lincolnville.