Arborvitaes are fast-growing evergreens that are both beautiful and useful to landscapes. With their thick, textured needles and drought-resistant nature, these low-maintenance plants are popular with homeowners seeking privacy screens or natural borders. In the video above, This Old House landscape contractor Jenn Nawada showcases her two favorite species of arborvitae and shares helpful insights on their care.
What Are Arborvitaes?
Arborvitaes, scientifically known as Thuja occidentalis, are versatile evergreen trees or shrubs belonging to the cypress family. These plants are renowned for their dense foliage, conical shape, and ability to thrive in various climates.
Characteristics of Arborvitaes
Arborvitaes have several distinctive features that make them a great choice for homeowners and landscapers:
- Conical or pyramidal growth
- Dense, scale-like leaves
- Evergreen foliage
- Relatively fast growth rate
- Soil adaptability
- Tolerance for full sun and partial shade
Common Uses in Landscaping
These versatile plants serve multiple purposes in outdoor spaces:
- Focal points in garden designs
- Foundation plantings
- Natural property borders
- Noise reduction barriers
- Privacy screens or hedges
- Windbreaks
Arborvitaes also stand out in winter by keeping gardens green even when other plants lose their leaves.
Types of Arborvitaes
While there are many varieties of arborvitaes, Nawada calls out two popular types.
Emerald Green Arborvitae
The Emerald Green arborvitae is an excellent choice for smaller spaces and tighter corridors. These are its key features:
- Compact size, typically reaching 10–15 feet tall and 3–4 feet wide
- Dense, bright green foliage that retains its color year-round
- Great for marking property lines or creating garden borders
- Ideal for creating privacy screens in smaller spaces
- Narrow, upright growth habit
It’s worth noting that Emerald Green arborvitaes aren’t deer-resistant, which may be a consideration for those living in areas with high deer populations.
Thuja Green Giant Arborvitae
The Thuja Green Giant, also known as the Western arborvitae, is a larger and more robust tree. Its characteristics include the following:
- Dark green, glossy foliage that keeps its color throughout the year
- Deer-resistant nature, making it suitable for woodland communities
- Excellent choice for creating natural borders or privacy screens in larger spaces
- Potential to reach heights of 40–60 feet with a spread of 12–20 feet
- Rapid growth rate, capable of growing 3–4 feet per year
This variety works particularly well in areas where plants can spread out and grow naturally without restriction. It is also remarkably hardy and adaptable, needing minimal care.
How To Plant Arborvitaes
The right planting method is crucial for your arborvitaes’ long-term health. Follow these steps to make sure your plants get off to a strong start:
- Choose an appropriate location with well-draining soil and good sunlight.
- Dig a hole twice as wide as the root ball and just as deep.
- Remove the plant from its container and gently loosen the roots.
- Place the arborvitae in the hole at the same depth it was in the container.
- Backfill the hole with a mixture of native soil and compost.
- Water thoroughly and apply a 2- to 3-inch layer of mulch around the base, keeping it away from the trunk.
- Continue to water regularly for the first growing season to establish a strong root system.
Planting in early fall can give arborvitaes ample time to acclimate and strengthen their roots before the onset of winter. While planting, make sure the arborvitaes are spaced evenly away from one another to accommodate their growth and get the best air circulation.
Keeping Your Arborvitaes Healthy
Arborvitaes are easy to maintain, but they still need some attention to keep them in good shape. Nawada shares some tips to keep these evergreens thriving.
Pruning Arborvitaes
While arborvitaes don’t require extensive pruning, some occasional trimming can help keep them healthy. Follow these tips:
- Remove any dead, damaged, or diseased branches as soon as you notice them.
- If you need to prune for shape or size control, do so in early spring before new growth emerges.
- When pruning, cut at a “V” where branches intersect to encourage natural-looking regrowth.
- For a formal look, shear the sides of the arborvitae in early spring.
- For a more natural appearance, allow the plant to grow with minimal intervention.
Pruning also helps improve air circulation within the plant, reducing the risk of fungal infections. Always use sharp, clean tools for cuts, which minimize stress on the plant.
Watering and Fertilizing
Good watering and fertilization practices can also help your arborvitaes thrive:
- Avoid over-fertilizing, as this can lead to weak, spindly growth.
- Once established, arborvitaes are relatively drought-tolerant but benefit from occasional deep watering during dry spells.
- Apply a slow-release, balanced fertilizer in early spring before new growth begins.
- Water deeply and regularly during the first growing season to establish a strong root system.
In sandy or poor soil conditions, consider amending the soil with organic matter or compost to enhance nutrient availability and moisture retention.
Protecting Arborvitaes in Winter
In colder climates, arborvitaes may need some shielding during harsh winters:
- Apply a 2- to 3-inch layer of mulch around the plant’s base to insulate the roots.
- If heavy snow is expected, gently tie the branches together to prevent splaying.
- Consider using burlap wraps or anti-desiccant sprays to protect against frost burn in exposed areas.
Snow can be gently brushed off from branches to prevent breakage. Avoid using de-icing salts near arborvitaes, as these can harm the foliage and roots.
Common Arborvitaes Problems and Solutions
While arborvitaes are hardy plants, they can face challenges. Here are some common issues and how to address them:
- Bagworms: Remove bags by hand or use appropriate insecticides if infestations are severe.
- Deer damage: Choose deer-resistant varieties like the Thuja Green Giant or use repellents and natural barriers, such as ivory soap.
- Root rot: Make sure the tree has proper drainage and avoid overwatering to prevent this fungal disease.
- Yellowing foliage: This could indicate overwatering, nutrient deficiency, or pest infestation. Adjust watering practices, apply a balanced fertilizer, or inspect for pests.
Seasonal Care Tips
Arborvitaes appreciate seasonal care to remain healthy year-round. In spring, apply a balanced fertilizer and prune as needed. During summer, regular watering is essential, especially in hot, dry conditions. In fall, a fresh layer of mulch helps insulate the roots, and inspecting for bagworms prepares the plant for winter.
Arborvitae Varieties for Different Climates
Selecting the right arborvitae variety for your climate is key to successful growth. In colder regions, consider Techny, which have excellent winter hardiness. For climates with heat and humidity, Green Giant and Steeplechase perform well.
Companion Planting with Arborvitaes
Arborvitaes can be paired with many plants to make your landscape look more dynamic. Ornamental grasses, flowering shrubs like hydrangeas, and perennials such as hostas complement arborvitaes well. This combination creates a gorgeous year-round garden display.
