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Care of Thuja Trees

By Charmayne Smith ; Updated September 21, 2017

The thuja tree is a hardy evergreen tree. Commonly referred to as the Green Giant, the thuja tree grows in a pyramidal form, reaching heights up to 60 feet tall. This rapidly growing tree is able to reach heights of 30 feet in just 30 years with maximum spread of 20 feet. Thuja is a relatively easy tree to cultivate and can be used as a privacy screen or hedge.

Choose a planting location for your tree. Thuja trees are fairly forgiving and can quickly adapt to most environments. Though the tree is flexible, it prefers a nutrient-rich, well-drained soil. It will grow in all types of soil, from sandy loams to heavy clays. The tree requires at least six hours of sunlight each day. The light can range from full, direct sunlight to partially light shade. Heavy shade is not recommended.

Consider the purpose of your thuja when you choose its location. The trees are ideal for privacy screens, hedges and topiaries. Plant thuja trees at least four feet apart to create a solid barrier. Height is also a consideration when planting. For privacy screens with a shorter height, plant the trees closer together. Plant thuja farther apart to create a taller barrier.

Water thuja regularly to promote healthy growth. Though the trees tolerate short periods of drought, they respond with browning and droopy foliage. In addition, thuja cannot tolerate wet feet, so water carefully. Water the thuja approximately once each week, adjusting for climate and rainfall.

Fertilize the young thuja with a well balanced fertilizer. The ideal fertilizer will incorporate nitrogen, phosphate and potassium. Increase the nitrogen levels slightly for mature trees. This will promote rich, darker foliage. Apply fertilizer twice monthly during the early spring and monthly during the growing season. Do not fertilize while the tree is dormant.

Trim and shape the tree, as desired. The thuja grows naturally in a pyramid shape and does not require pruning. Shaping can begin once the tree has established itself. Wait at least four weeks for establishment.


Things You Will Need

  • Water
  • Fertilizer

About the Author


Writing professionally since 2004, Charmayne Smith focuses on corporate materials such as training manuals, business plans, grant applications and technical manuals. Smith's articles have appeared in the "Houston Chronicle" and on various websites, drawing on her extensive experience in corporate management and property/casualty insurance.