Arborvitae Tree Identification

Size and Form

• Arborvitae in the wild grows between 30 and 60 feet tall, with widths between 10 and 15 feet. Trunk diameters reach between 1 and 3 feet. The arborvitae possesses a narrow conical form, at times appearing nearly pyramidal. Arborvitae can have multiple trunks or just one. Trunks of arborvitae often feature branches all the way to ground level. The buttressed trunks of arborvitae have a thin and almost scaly covering of brown-shaded bark.

Foliage

• The evergreen foliage of arborvitae, composed of very small scale-like and overlapping leaves that completely cover the twigs, turns yellowish-green to brown in severe winters. The outer twigs usually grow in the same vertical plane, forming what the Ohio Department of Natural Resources calls "sprays." Each leaf is no longer than 1/8 inch. The twigs are difficult to see because the foliage obscures them, but they are an array of colors, including orange, green and yellow.

Flowers and Cones

• Yellow male flowers occur on the arborvitae but fall off in the spring. The green female counterparts turn into upright cones that add little ornamental interest to an arborvitae. The cones, composed of between eight and 10 light brown scales, are rarely longer than ½ inch. Two very small seeds exist in some of the cone scales, protected from the elements until the cones open up and disperse them. The cones stay on the tree through almost all of the winter months before falling off.

More Identification Keys

• Look for arborvitae growing in the wild in swamps, wet areas and damp forests. The trees often grow together to form large stands. Those in full sun are more robust. Those in partial shade have an open crown of branches and look somewhat scraggly. Arborvitae is a host plant of the bagworm, the larvae of a moth capable of defoliating the tree during times of infestation. The bagworm cocoon, which can remain on the tree all winter long, looks like part of the tree, but it hangs downward, as opposed to the cones, which grow upright on the tree's branches.