When homeowners look for the perfect evergreen to create a dense, year-round privacy screen, the Mission Arborvitae (often sold as Thuja occidentalis ‘Techny’) is almost always at the top of the list. Known for its robust hardiness and thick, dark green foliage, it is one of the most reliable landscaping shrubs you can plant.
Unlike many other arborvitae varieties that turn an unsightly bronzy-brown during harsh winters, the Mission Arborvitae retains its deep green color year-round. Whether you want to let it reach its majestic mature height of 15 feet or keep it pruned into a neat, low hedge, this guide covers everything you need to know to grow and protect these beautiful evergreens.
Best Arborvitae Varieties for Tight Spaces
A recurrent problem for garden lovers is finding evergreen plants for cramped areas in the landscape. Surprisingly few trees or shrubs fit into narrow spaces without requiring constant, aggressive pruning. If you have limited space but still want four-season drama, consider these two spectacular narrow varieties:
- ‘DeGroot’s Spire’: Discovered in 1970, this is an exceptionally slender form of arborvitae. Its medium-green foliage is slightly twisted and turns a rich, mossy green during the cold. It will reach 15-20 feet tall but stay a mere 3-4 feet wide.
- ‘Jantar’ (Amber Gold): Originally discovered in Poland, ‘Jantar’ is an eye-popping yellow during spring and summer. As cool weather approaches, it takes on a warm amber-gold hue. It features dense lateral branches and forms a striking vertical element, reaching about 10 feet tall and 2-3 feet wide.
How to Plant Arborvitae for a Solid Hedge
If your goal is to create a solid, impenetrable privacy hedge, proper spacing and soil preparation are critical.
- Spacing: Plant Mission arborvitae trees exactly 4 to 6 feet apart. This allows them enough room to establish healthy root systems while ensuring their canopies will seamlessly merge together in just a few years.
- Location: Choose an area that receives full sun to partial shade. Arborvitaes grown in full sun will be much denser, while those in partial shade may have a slightly looser foliage structure.
- Digging the Hole: Dig a hole that is twice as wide as the root ball, but only just deep enough so that the top of the root flare remains 1 to 2 inches above the surrounding ground level. Planting too deep will smother the tree.
Watering and Soil Requirements
Because they are native to riverbanks and shorelines, arborvitaes do not like to dry out. Mission (Techny) arborvitae is no exception. During the scorching heat of summer, it requires regular, deep watering, especially during its first two years of establishment. Heavy mulching around the base is highly recommended to retain soil moisture.
However, while they love moisture, they absolutely hate standing in soggy, waterlogged soil. If you have heavy clay that doesn’t drain, your arborvitae will suffer from root rot. Amend clay soil with organic compost before planting to ensure adequate drainage.
Protecting Arborvitae from Winter Snow and Pests
1. The Danger of Heavy Snow
If you live in an area that gets heavy winter snowstorms or freezing rain, you must protect your arborvitae. Heavy, wet snow acts like a wedge, pulling the upright branches apart. Once the branches are bent over and splayed open by ice, they will permanently settle in that deformed shape.
In late fall, take heavy-duty twine or specialized tree wrap and gently bind the top half of your arborvitae together. This keeps the multi-stemmed structure tight and prevents heavy snow loads from splitting the center of the tree.
2. Deer Damage
Arborvitae is generally a robust plant with remarkably few insect pest issues (occasionally spider mites, which give the foliage a dusty gray tone). The most common and devastating “pest” is actually the white-tailed deer. Deer treat arborvitae like an all-you-can-eat winter buffet, munching the foliage from the ground up to about 5 feet high, leaving the bottom of the tree completely bare.
You can try applying strong scent-based deer repellents, but they must be reapplied frequently, especially after heavy rain. The only foolproof option for severe deer pressure is installing a physical barrier or netting around the hedge during the winter months.
Frequently Asked Questions
How fast does Mission Arborvitae grow?
Mission (Techny) arborvitae is considered a moderate to fast grower. Once properly established in well-draining soil with adequate sunlight, it can grow between 12 to 24 inches per year until it reaches its mature height.
Do arborvitaes need to be pruned?
While they naturally maintain a beautiful pyramidal shape without sheering, the first years of life are critical. Minor maintenance pruning to ensure a single, strong central leader (stem) is crucial. Eliminate competing, co-dominant stems when the plant is young to build a better overall structure for maturity.
Why is my arborvitae turning brown inside?
If the inner foliage near the trunk is turning brown and dropping in the fall, do not panic! This is a completely normal process called “seasonal needle drop.” However, if the outer tips of the branches are turning brown, it is a sign of severe drought stress, winter burn, or root rot from poorly draining soil.
