These slow-growing trees create dense evergreen foliage that can make excellent “living walls” when privacy is needed in the garden. Some varieties take on a bronze cast in the fall and winter, so be selective when picking an arborvitae variety to plant in your yard. These trees stand up well to trimming and can be made into whimsical topiary plants to create living garden art. Arborvitae have long been used for their various medicinal properties.
The Tree of Life
Native to North America, these rugged evergreen trees are often found growing in places where little else might. When early French settlers reached North America, they learned from Native Americans that these plants could be used to treat scurvy, a disease caused by vitamin C deficiency that many of the sailors were suffering from. Young foliage happens to be high in this nutrient, and it led it to the plant being named arborvitae, which translates to "tree of life." Be extremely cautious, though—it's harmful if used in excess, due to the neurotoxic compounds in the plant. These trees have also been used as food (in small amounts), lumber, and for their cleaning properties.
Arborvitae Care Must-Knows
Arborvitaes grow best in consistently moist, almost swampy soils. While they love full sun, they can also manage in part shade. Their biggest downfall is drought conditions, especially during and leading up to winter. If fall has been dry, give these plants (especially young ones) supplemental water. This also helps prevent one of the biggest problems with arborvitaes: winter burn.
Planting arborvitaes in dry soil and exposed to winds during the winter will likely cause winter burn. The first sign of winter burn is browning of the leaves. In severe situations, this can cause significant damage to arborvitae and may even kill them. Luckily, there are newer, burn-resistant varieties you can plant. You can also site your arborvitae out of direct sunlight and wind. Wrapping young and sensitive plants in burlap can help as well.
A few pests may bother your arborvitae. Spider mites can appear, especially during the hot and dry days of summer. Unfortunately, by the time you find these pests, it'll be too late, as you'll most likely notice browning foliage due to their feeding that can't be reversed. Use an insecticidal soap or horticultural oil, but be careful if it is during the heat of the summer because these sprays can also cause the plants to burn.
Bagworms can also attack arborvitae. Much like spider mites, you may not notice these pesky worms until the damage is already done. Typically in midsummer, you may notice little, brownish "bags" that look like small pine cones hanging all over your tree. These are actually the cocoons of bagworms. After eating their fill of foliage, bagworms will spin their cocoons; as they work, they cover the outside with little bits of leaf debris, camouflaging their resting place. Come spring, these little caterpillars will crawl out of their cocoons and fly out in search of a new host. The ideal time to treat them is as they are hatching, typically beginning in June. One of the safest things to spray while they are feeding (before hibernation) is Bacillus thuringiensis, but it's important to time this treatment correctly.