Tips on Planting Arborvitaes

Arborvitae trees, members of the cypress family, are statuesque evergreens with flat, fine-needled foliage and symmetrical shapes. Fast-growing and hardy, they perform well as individual plantings, hedges and natural privacy screens and wind blocks. Since they can survive where winter temperatures drop to -35 degrees F, they are grown as far north as Zone 2 in Canada and as far south as Virginia. Arborvitae establish roots quickly. By using basic gardening techniques, you can guarantee that your arborvitae thrives.

It's important to know how big your arborvitae will grow, and select trees accordingly. The fast-growing Thuja Green Giant reaches 40 feet tall and 20 feet wide. This imposing tree goes bronze in the winter, but turns green again as the weather warms. The dark-green American arborvitae tops out at 20 to 30 feet high, retains rich green color through the winter months, and has an attractive pyramid shape. The Emerald Arborvitae, which originated in Denmark, is more petite, reaching a top height of 15 feet and a width of 4 feet. It keeps its bright green color throughout the winter, and is tolerant of both cold and heat.

Arborvitae need moist, well-drained, slightly acidic soil that is slightly elevated. The site should receive between three hours and six hours of full sun a day; avoid putting the tree where it could be scorched by intense afternoon sun. Spring and early summer are the optimal times to plant your tree, although arborvitae can also be successfully planted in late winter. Select a 2- to 3-foot tall specimen from a reputable nursery, and dig a hole as deep as the burlap root ball, and one and a half times as wide. Amend the soil with nutrient-rich organic compound and place the tree in the hole, centered and straight. If the root ball is wrapped in natural burlap, plant the burlap with the tree, but make sure the edges are buried. If it is encased in synthetic burlap, slit the fabric in several places around the root ball so the roots can establish themselves. Backfill with garden soil and compost, tamping soil down lightly, and water liberally.

To avoid edges of branches turning brown, don't prune arborvitae in summer. Arborvitae should be covered in winter to prevent damage from snow and ice buildup, but avoid using burlap; it can cause mold and mildew. Heavy-duty, multistrand netting is a better choice, and has the advantage of being a complimentary green color. Like many plants, arborvitae can develop mold and mildew diseases; avoid overhead watering and observe good garden sanitation. Avoid over-watering by giving a thorough soaking no more than once a week.