Planting Arborvitae: 5 Tips for Planting Arborvitae

American arborvitae (Thuja occidentalis) is a native evergreen tree with several practical landscaping uses. Arborvitae is a type of conifer tree with dark green foliage that grows in a narrow, pyramid shape. They're often planted in rows as a windbreak or privacy screen; their dense growth habit also makes them perfect for shaping into a decorative topiary. Popular cultivars include the ‘Emerald Green’ arborvitae and ‘Green Giant’ arborvitae. Parents and pet owners should be advised that these plants are toxic to animals and humans if ingested.

The best time to plant arborvitae trees is after the last frost in early spring or in the late fall before the ground hardens. Arborvitae trees are hardy in USDA hardiness zones three to eight and do well in a range of soil types.

1. 1. Choose a location with full sun. Arborvitae trees thrive in full sun conditions but will tolerate partial shade. When planting arborvitae, keep in mind that they can reach a mature size upwards of twenty feet tall. To accommodate this growth, plant your tree fifteen to twenty feet away from buildings, power lines, and other trees.
2. 2. Prep your tree. Most garden centers sell arborvitae with the root ball wrapped in burlap. Remove the burlap, and spray down the root ball with a garden hose.
3. 3. Dig your hole. To ensure enough space for the root system, your planting hole should be between two to three times deeper and wider than the root ball. Keep in mind that mature trees can reach up to ten feet wide when left to their own devices. If you do not plan on regularly pruning your trees, you may want to consider spacing them ten feet away from neighboring plants. Otherwise, they can be planted closely together in a row if pruned regularly.
4. 4. Plant your arborvitae. Before placing your arborvitae in the planting hole, use your hands to gently loosen up the root ball. Place the tree into the hole and backfill with soil so that the top of the root ball is roughly level with the top of the hole. Once the hole is half full of soil, soak the root system with water from a gardening hose to get rid of any air pockets in the soil. Continue to backfill until all the empty space around the root ball is filled. Gently tamp down the soil, then water deeply.
5. 5. Apply a layer of mulch. At the base of the tree, apply a three-inch layer of mulch to help keep the soil moist.

Arborvitae trees are relatively low-maintenance. They have a slow to moderate growth rate and will not require constant pruning if spaced properly. However, there are a few plant care tips to follow to ensure that your arborvitae will thrive.

1. 1. Keep the soil moist. Arborvitae trees do best in consistently moist soil, but overwatering will cause root rot. Use a soaker hose or drip irrigation system to deliver deep, consistent watering throughout the spring and summer growing season—especially during the tree's first year of growth.
2. 2. Fertilize your tree as needed. Arborvitae trees don't require fertilizing to survive, but if your tree’s growth is slow or sparse, apply a slow-release fertilizer once during the growing season to help promote new growth.
3. 3. Prune your tree in the spring. Pruning arborvitae in the spring will keep its foliage thick and looking neat. Trim just the leafy parts of the branches, being sure not to cut it all the way back to bare wood. Clip off dead stems to prevent diseases from spreading to the tree.
4. 4. Keep an eye on pests. Arborvitae trees are relatively pest-resistant; however, they can occasionally become infested by bagworms or spider mites. The best way to control these pests is to physically remove them by spraying the tree with a garden hose.

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