Arborvitae are the workhorses of the landscape. These rugged, native North American evergreens thrive where other plants struggle, offering dense greenery, formidable privacy screens, and surprising versatility. While they are known for being low-maintenance, achieving truly professional results requires a bit more strategy than just digging a hole. Whether you dream of a living wall, a sculptural topiary, or a stately windbreak, mastering the specific steps to grow arborvitae will set you up for decades of success. This guide breaks down the process into eleven critical actions, from selecting the perfect variety to ensuring your trees survive their first winter.
Step 1: Choose the Right Arborvitae for Your Space
Not all arborvitae are created equal. The genus Thuja includes both trees and shrubs, with mature heights ranging from a compact 2 feet to a towering 60 feet. Selecting a variety that matches your site is the single most important decision you will make.
For a dense privacy screen that stays manageable, the ‘Green Giant’ is a popular hybrid that can add 3 to 5 feet of growth per year, eventually reaching 50 to 60 feet. If you have limited space or want a low hedge, consider dwarf cultivars like ‘Hetz Midget’ or ‘Little Giant’, which stay under 4 feet. For colder climates in USDA Zones 2 through 4, stick with Eastern arborvitae (Thuja occidentalis) cultivars like ‘Techny’ or ‘Smaragd’ (Emerald Green), which offer superior cold tolerance down to -40°F. Planting a giant variety under a power line or too close to a house is a common mistake that leads to expensive removal later.
Step 2: Pick a Sunny, Well-Drained Location
Arborvitae are sun-lovers at heart. To grow arborvitae with thick, lush foliage, you need to provide at least six hours of direct sunlight each day, with morning sun being particularly beneficial. While they tolerate partial shade, too much darkness causes the interior foliage to turn brown and drop off, leaving you with a sparse, leggy plant.
These trees also demand consistently moist but well-drained soil. Avoid low spots where water pools after a rain. Standing water around the roots is a fast track to root rot, a fatal condition for arborvitae. If your yard has heavy clay soil, consider building a slight berm or raised bed to improve drainage. The ideal pH range is neutral to slightly alkaline, between 6.5 and 8.0, which is common in many North American soils.
Step 3: Time Your Planting Correctly
Timing is everything when you want to grow arborvitae successfully. The best windows for planting are early spring, after the last frost has passed, or late fall, about six weeks before the ground freezes solid.
Spring planting gives the roots a full growing season to establish before winter’s chill arrives. Fall planting works well because the cooler air temperatures reduce stress on the foliage while the soil remains warm enough for root growth. Avoid planting in the heat of summer, as the combination of high temperatures and a compromised root system can cause severe transplant shock. If you must plant in summer, be prepared to water deeply and frequently.
Step 4: Prepare a Generous Planting Hole
The hole you dig is the foundation of your tree’s future. A common mistake is digging a hole that is too deep or too narrow. For a professional result, dig a hole that is two to three times the width of the root ball but exactly the same depth.
Wide holes allow the roots to spread outward into the surrounding soil, encouraging a stable, self-sufficient tree. If the hole is too deep, the root ball will settle below ground level, causing the trunk to rot. After digging, remove the tree from its nursery container. Gently loosen the outer roots with your fingers. If the roots are circling the pot, make a few vertical cuts with a sharp knife to encourage them to grow outward instead of continuing to circle.
Step 5: Plant at the Correct Depth
This step is non-negotiable for long-term health. The top of the root ball should sit level with the surrounding soil, or even an inch or two above it in heavy clay soil. Never bury the trunk with extra soil.
Place the tree in the center of the hole. Backfill the hole halfway with the original soil you removed (no need for fancy potting mixes). Soak this layer thoroughly to settle the soil and remove air pockets. Then, finish backfilling the hole to the top edge of the root ball. Do not pile soil up against the trunk. Water the entire area deeply again. This two-stage backfilling and watering process ensures the roots have good contact with the soil from the start.
Step 6: Water Deeply and on a Schedule
Watering is the most critical care task for the first two years. Arborvitae are thirsty plants, and inconsistent watering leads to stress, browning, and vulnerability to pests. The goal is to grow arborvitae with a deep, robust root system.
For the first year, provide a weekly, low-and-slow watering. Use a soaker hose or a garden hose on a trickle at the base of the tree for 30 to 60 minutes. The water should penetrate the entire root mass, not just wet the surface. Check the soil moisture by feeling an inch below the surface. If it is dry, it is time to water. In hot, dry weather, container-grown arborvitae may need water every single day. After the first year, water deeply whenever the top inch of soil feels dry, directing the water several inches from the trunk under the canopy.
Step 7: Apply a Layer of Organic Mulch
Mulch is a professional’s secret weapon. A 2- to 4-inch layer of organic mulch, such as shredded bark or wood chips, creates a stable environment for the roots. Apply it in a flat ring around the base of the tree, but keep it a few inches away from the trunk to prevent rot.
Mulch conserves soil moisture by reducing evaporation, which is vital during dry spells. It also moderates soil temperature, keeping roots cooler in summer and warmer in winter. Over time, the mulch breaks down and adds valuable organic matter to the soil, improving its structure. This simple step dramatically reduces the need for frequent watering and suppresses competing weeds.
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Step 8: Space Trees Correctly for Screens
If you are planting a hedge or privacy screen, proper spacing is crucial. The goal is to create a solid wall of green without crowding the trees to the point of stress. For most large arborvitae varieties, allow 3 to 4 feet between the centers of each tree.
This spacing allows the branches to interlock as they mature, creating a seamless barrier. Planting too close together (under 2 feet) forces the trees to compete for water and nutrients, leading to sparse, weak growth and increased disease risk. For a windbreak, you can space them slightly farther apart, about 5 to 6 feet, as the primary goal is to slow wind, not create a solid wall. Always research the mature width of your specific variety and adjust spacing accordingly.
Step 9: Prune Strategically in Spring
Arborvitae are forgiving of pruning, but they have specific needs. The best time to prune is in early spring, just as new growth begins to emerge. This gives the plant a full season to recover and fill in any gaps.
Focus on removing dead, damaged, or diseased limbs. You can also lightly shear the tips to encourage denser growth or shape the plant into a formal hedge or topiary. Never cut back into the brown, bare wood in the center of the plant, as this area rarely produces new growth. If you prune too late in the summer, you risk encouraging new growth that will not harden off before the first frost, making it vulnerable to winter burn.
Step 10: Protect Against Winter Burn
Winter burn is a common problem, especially in colder zones and for newly planted trees. This occurs when the foliage loses moisture to wind and sun, but the frozen ground prevents the roots from replacing it. The result is browning, often on the side facing the sun or wind.
To prevent this, keep your arborvitae well-hydrated going into winter. Water deeply until the ground freezes. Apply a fresh layer of mulch (2 to 4 inches) to insulate the roots. For added protection, especially for smaller trees, consider wrapping them in burlap or installing a windbreak of snow fence on the windward side. Do not use plastic sheeting, as it traps moisture and heat, which can damage the tree. Some varieties naturally develop a bronze cast in winter, which is normal and not a sign of damage.
Step 11: Monitor for Pests and Problems
While arborvitae are generally tough, they are not immune to issues. The most common pests are bagworms, spider mites, and deer. Bagworms create spindle-shaped bags on the branches and can defoliate a plant quickly. Pick them off by hand in fall or winter, or treat with a biological insecticide (Bacillus thuringiensis) in late spring.
Spider mites cause a stippled, dusty appearance on the foliage. A strong blast of water from the hose can dislodge them. Deer will browse on arborvitae, especially in winter when other food is scarce. Physical barriers like fencing or deer repellents are the only reliable solutions. If you notice progressive browning on one side of the tree, it is likely winter burn or a root issue, not a pest. If the entire tree turns brown, it has likely died and should be removed to prevent potential disease spread.
With these eleven steps, you are equipped to grow arborvitae that will thrive for decades, providing beauty, privacy, and structure to your landscape. The upfront effort of careful selection and planting pays off with a resilient, low-maintenance evergreen that enhances your property year-round.
