One of the most popular ornamental plants, arborvitae trees are a mainstay in landscape designs, both commercial and residential. These low maintenance, easy to grow trees are a gardening dream that can play a variety of roles. Whether you’re looking to grow a privacy hedge to keep prying eyes out of your yard or a windbreak to slow winter squalls, planting arborvitae is a good idea.
Growing arborvitae isn’t tricky, but to get your trees off on the best foot possible, it’s essential you know how to plant them. So let’s talk about the what, when, where, and how…
Historically, arborvitae was a prevalent plant with Native Americans for their medicinal purposes. The name itself means “tree of life.”
Over time their purpose has changed, but they are still among the most popular trees in landscape designs. Known for their dense evergreen foliage, easy-going nature, and iconic pyramid shape, they also work well as:
- Privacy Screens
- Living Fences
- Ornamental Plantings
When to Plant
Like many other plants, it’s best to plant trees and shrubs when they are not actively growing to minimize stress. This typically means late winter or early spring, depending on winter conditions and how soon the soil is workable (i.e., does the soil freeze or not).
Avoid planting in the fall. Trees need time to establish their root systems before winter. This can be done, though, if you live in a climate where the winter conditions are milder.
Where to Plant
Consider planting your trees in the following places:
- Plant on the north side of your property to create an efficient winter windbreak.
- Plant on the south or west side of your property to shade your home from the sun.
- Plant wherever you need to construct a privacy screen, a living fence, or a hedge.
Arborvitae are tolerant of many climates, thriving in USDA growing zones 3 through 7. They are not as tolerant with drought, and as such, they don’t handle the heat as well as the cold.
Choose a spot in your landscape where trees will be in either full sun or partial shade; they need a minimum of six hours of direct sunlight daily.
Type of Soil
It’s a common misbelief that arborvitae will grow anywhere you stick them, regardless of the soil type or terrain. Their expansive root systems need to grow easily through the soil, and they don’t like to have their “feet” soggy, so they prefer soils with the following characteristics:
- Free of rocks
- Rich in organic matter
- pH values between 6.5 and 8.0
If your soil doesn’t fit those parameters, you can amend it by adjusting the pH, digging out large rocks, or adding finished compost or well-rotted manure.
Arborvitaes are often planted closely together when they are young; as they grow they don’t have the space they need for both above ground and below-ground growth.
Trees that grow tall must have a broad spreading root system that grows wide and deep to anchor the top-heavy plants into the ground. To ensure they have enough room when fully mature, it’s important to space young trees properly.
How far apart should to plant?
The answer to this depends upon what lies nearby and the variety you are planting. For instance, the Green Giant varieties needs more room than the emerald green varieties.
- Space them ten feet from other arborvitaes to account for their mature size unless you plan on trimming them regularly as they grow. As they mature, they will fill in the gaps.
- Spaces shrubs grown for a hedge slightly closer together, leaving about five feet between them.
- Space them twenty feet from other large trees to avoid competing for water and soil nutrients.
- Space them ten feet from your home, garage, or paved areas to avoid encroachment.
The steps to getting arborvitae in the ground are similar to planting other trees. Overall, the process is fairly straightforward but will require some physical labor, especially if large.
Try to plant on overcast days or during the cooler evening hours to minimize planting stress or shock.
- Use a round-point digging shovel to dig a hole that is approximately as deep as the container and twice to three times as wide, setting the dirt removed to the side. If the arborvitae is wrapped in burlap, dig the hole a couple of inches deeper than the root ball and two to three times as wide.
- Remove the tree from its container or burlap wrap, depending on how it was purchased. To get it free from a container, you can lay it on the ground, on its side, and tap the pot to help loosen it. If need be, carefully cut the container free. Burlap and any wires securing it to the root ball should be carefully cut, removing as much as possible.
- Loosen the outside of the root ball slightly with your hands, taking care to not damage the roots or break any off.
- Remove any roots that appear dead or show signs of damage. Healthy roots appear white and are firm to the touch.
- Set the plant in the center of the planting hole, so the root ball’s top is even with the soil surface or slightly above it. To raise it in the hole you can add a few inches of the fill dirt to the bottom, creating a slight mound.
- Fan the roots out in the bottom of the hole to encourage outward growth.
- Backfill the hole with the removed soil, until it is even with the soil surface or slightly above.
- Periodically tamp the soil to remove any air pockets, while ensuring the tree stays upright. This may be easier if you have another set of hands to hold the tree in place.
- When the hole is completely backfilled, water the soil well to soak the entire root ball.
- Anchor the trees to the north and south to prevent crooked growth due to winds.
- Lay down a three-inch layer of mulch around the tree’s base, taking care to keep the mulch about one inch from the trunk.
One of the great things about growing arborvitae is they are fairly low maintenance and don’t need a lot of extra pampering. However, it’s crucial they get both the water and fertilizer needed for optimal growth.
Newly planted trees need approximately 20 to 30 gallons of water a week, which equates to 1 to 2” of rainfall. After the first or second growing season, the root system is established enough you can taper off the watering slightly.
If you live in an area where rainfall is less than this, you will need to water the tree by hand. When watering, longer soakings at infrequent intervals are better than short, regular bursts of water. This helps to drive roots deeper in search of water and makes plants more tolerant of drought.
Trees are continually pulling nutrients from the soil to complete the metabolic processes that result in growth. As they do this, they continuously use up the soil nutrients, making it necessary to replenish them over time. This is where fertilizers come into play for arborvitae.
To prevent nutrient deficiency symptoms, apply an all-purpose, landscape fertilizer formulated for trees and shrubs in the spring as plants come out of dormancy. Typically fertilizers higher in nitrogen such as a 3-1-1 ratio work very well. Follow the manufacturer’s directions to avoid over-fertilizing. While a little fertilizer is good, too much is a bad thing.
Frequently Asked Questions
Q. How Fast Do They Grow?
A. They are relatively fast-growing, which lends to their popularity as a privacy hedge, living fence, windbreak, etc. Depending upon the variety, they can put on two to three feet of vertical growth annually.
Q. Why is My Arborvitae Turning Brown?
A. They most commonly turn brown in the summer due to lack of moisture, especially during high temperatures. Browning in the winter is from winter burn, stemming from a combination of lack of water, wind, and low temperatures. Make sure to check out our article on browning for all the possible considerations if your tree is starting to turn brown.
Q. Do Deer Eat Them?
A. Unfortunately, deer will eat many varieties. A select few types have evolved through breeding and experimentation that appear to be deer-resistant. However, if deer populations are starving, they will eat almost anything, including the deer-resistant varieties.
Q. Can I Plant Them in Rocks?
A. Arborvitae grows best when planted in soils that are loose and free of rocks or heavy dirt clods. They have extensive root systems needing soil they can easily grow in, allowing the roots to move both down through the soil and laterally.
Q. Does They Need to Be Pruned?
A. No, they don’t need pruning like some other trees or shrubs. They will naturally grow into their well-known conical shape. Some people choose to trim their arborvitae back to maintain a specific size or to keep it from creeping too close to their homes or onto neighboring properties.
Q. Is It Poisonous to Dogs and Cats?
A. Arborvitae is not considered highly poisonous to dogs. If it is consumed in high quantities, it can cause skin rashes or gastrointestinal discomfort.