American Arborvitae

Evergreens are valuable plants in any garden, bringing permanence and stability to it, giving year-round color, screening and structure. In colder zones many of the widely used evergreens simply cannot survive, as low temperatures are particularly difficult for them to tolerate and cause extensive burning and death of foliage. In those colder zones we still need reliable, easy-to-grow evergreens, that will tolerate a range of garden conditions, and with a diversity of potential uses. For that, nothing comes close to matching the overall utility of the American Arborvitae. This tree – native to large parts of North America, is amazingly cold-tolerant, and it survives even when winter low dip to a chilly minus 50 degrees. Whether you call it White Cedar, or Arborvitae, this terrific plant is always there when you need it, and indispensable for screening and hedges.

The American Arborvitae is an upright growing, columnar evergreen tree that will in time be over 20 feet tall, and can eventually reach as much as 40 feet, depending on the conditions it grows in. It has a width of only 10, or at most 15 feet, and the foliage is kept low to the ground for many years, with trees only developing a trunk of any height after a decade or two. A conifer, it does not have the typical needles we see with other conifers like pine trees – instead it has tiny, scale-like needles that cover the thin young branches tightly, making them appear bright green. These young branches are clustered into fan-like sprays, making a dense, full look to even unclipped plants. Trunks and older branches have attractive silvery-red bark, which peels away in long vertical strips, making an attractive effect. As a conifer this tree doesn’t flower, but on older plants you will see clusters of small cones, about ½ inch long. These begin yellowish-green, and mature to a light brown, when they split open and release seeds.

With its attractive upright form, dense growth, and rich green foliage, the American Arborvitae is perfect as a specimen tree in a lawn, alone or in clusters of 3 or 5. Placed in the corners of your property they give a sense of enclosure, and complete the scene, and individual trees can also be placed among large shrubs, to provide a vertical accent and winter interest. Since it is native, planting along the edges of woodland will enhance it, without upsetting the ecology. It enjoys water, so this plant looks great along a stream, by a pond or lake, or in any low-lying, damp areas.

Growing American Arborvitae Trees

For many gardens, the American Arborvitae is first and foremost a plant for screening and hedges, left to grow naturally, or trimmed for a neat look. In colder regions it is the classic hedging plant, and many gardens are enclosed with such hedges or screens. For a natural screen, plant 5 or 6 feet apart, and for clipped hedges 3 foot spacing is right. Don’t plant too closely, as each plant needs to develop well, and if you plant too close, some of the plants will eventually die, leaving awkward gaps in your hedge. As well, they will struggle for the light, and the lower branches will die, leaving that vital part of your hedge bare and open. This tree grows at a rate of 6 to 12 inches a year when young, slowing as it matures to 1 or 2 inches a year. Plants that are trimmed regularly will continue to develop about 6 inches of new growth between trimmings. 

The American Arborvitae grows well from zone 2 to 7. In very cold zones some bronzing of the foliage in winter is normal, and plants quickly green-up again when spring comes. A very adaptable and tough plant, it will grow in most soils, if they are not too dry, and it grows well in wet conditions too. Young plants should be given plenty of water, but mature trees will tolerate ordinary periods of summer drought well, at least in cooler zones. It has no important pests or diseases, and any damage is much more likely due to drought and lack of basic care, than to pests. 

Trim as desired, between late spring, after the first flush of new growth, up until early fall. Avoid trimming later in fall, or during hot, dry weather. Trimming makes the growth very dense and lush, allowing solid hedges and formal specimens to be easily created. When trimming hedges, keep the top narrower than the bottom, to allow light to the ground, and to keep the lower parts green and thick for many years. Do not trim into bare wood, as it cannot re-sprout, so trim little and often. Plants that are clipped regularly should be fed in spring and perhaps again in late summer, to keep them green and vigorous, and feeding is beneficial for unclipped plants too. Don’t fertilize too late in the season, especially in cold areas, as late new growth may be killed by cold. In late fall, plants should be watered deeply, before the ground freezes, to protect from winter burn. 

History and Origins of American Arborvitae Trees

The American arborvitae, Thuja occidentalis, grows wild in eastern Canada, and in the north-eastern states, from Minnesota to Maine, and as far south as the mountains of Tennessee. It is usually found in rocky soils, around lakes, and along streams, and on cliffs, in mountains and in wetlands. This is a very long-lived tree, and some are among the oldest trees in North America – over 1,000 years old. The name ‘arborvitae’ means ‘tree of life’ because a tea made from the foliage contains high levels of vitamin C. The French explorer Jacques Cartier was shown this by native Americans, saving the lives of members of his expedition.

There is a lot to be said for growing the natural form of trees, especially native ones, without always planting special garden varieties. For the best hedges, this is especially true. Choose the American arborvitae in its natural form, like many other gardeners do. Our stock is selling fast, so order now, while we still have plants left for you.