A techny arborvitae tree should be planted in an area with full or partial sunlight in soil mixed with compost. If several are planted together, they should be spaced far enough apart to give them room to grow. The tree should be fully saturated with water after planting and watered once a week during the summer. It should be fertilized once a year in the spring.
Techny arborvitae trees can handle most types of soil, but prefer moist loam that drains well. When planting, the hole should be as deep as the roots of the tree and slightly wider. Mixing compost, peat moss or leaves into the dug soil improves richness and drainage. If the root ball is wrapped in natural burlap, the wrapping will decompose and can be planted as-is. However, synthetic or chemically-treated wrappings, as well as strings, staples and wires, must be removed. Set the root ball in the center of the hole. Half-fill it with the enriched soil. After watering, fill it the rest of the way with soil and water again. During the next week, as you notice the soil settling, add more soil.
Techny arborvitae are conical trees and are often planted as hedges. If they have sufficient space to grow, they reach heights of 15 to 20 feet. They do not often have problems with insects or disease, though they should be monitored occasionally for spider mites and bag worms. If these pests are detected early, they can be easily controlled with pesticides.