Arborvitae (Thuja) are popular evergreen conifers often used for privacy screens and landscape accents. As these trees mature, their size may necessitate relocation within a property. Successful transplanting requires careful technique to minimize root disturbance and subsequent stress. Success depends directly on proper preparation and diligent aftercare to help the tree establish itself in its new environment.
Determining Feasibility and Optimal Timing
The possibility of transplanting an arborvitae depends highly on its size and age. Smaller specimens relocate with significantly greater ease and have a higher survival rate. Trees under six feet in height are generally manageable to excavate and move intact. Specimens established for more than eight to ten years, or those exceeding ten feet, possess extensive root systems that make a successful transplant very difficult.
The optimal window for moving arborvitae is during the dormant season, allowing the tree to recover from root damage before active growth or summer heat begins. The best times are in early spring before new buds break or in early fall (late August through early November). These periods offer cooler temperatures and adequate moisture, promoting new root growth. Avoid moving the tree during mid-summer heat, drought, or when the ground is frozen, as these conditions severely increase the risk of transplant shock.
Preparing the Arborvitae for Relocation
Preparing the tree begins several days in advance by deeply watering the soil surrounding the trunk. This pre-watering saturates the root ball, helping the soil hold together during excavation and minimizing moisture stress. The size of the root ball is paramount for survival. A general guideline is to allow for eight to twelve inches of root ball diameter for every one inch of the trunk diameter, measured six inches above the ground.
To begin excavation, use a sharp spade to cut a circle around the tree at the determined root ball diameter, pushing straight down to sever surrounding roots. This action, known as undercutting, defines the root ball and helps retain the fine feeder roots necessary for water and nutrient uptake. Once the trench is dug, carefully work the spade underneath the root ball to sever deeper taproots and gently lift the tree out of the ground.
Immediately after lifting, the soil mass must be secured to prevent crumbling during transport, which is highly damaging to the roots. Wrap the entire root ball in heavy burlap or durable plastic sheeting and tie it tightly with twine or rope to maintain structural integrity. For particularly large arborvitae, utilizing a wire basket over the burlap provides additional support to keep the soil firmly packed around the roots.
Site Preparation and Replanting Procedures
Before the tree is moved, the new planting location must be fully prepared. The new hole should be dug two to three times wider than the root ball diameter, but no deeper than the root ball height. This wide, shallow hole provides loosened soil for new lateral roots to easily expand into, while preventing the tree from settling too deep after backfilling.
When placing the arborvitae, confirm that the root flare—where the roots spread from the trunk—is positioned at or slightly above the surrounding soil grade. Planting too deep is a common error that restricts oxygen exchange and can lead to trunk rot and tree decline. Once the tree is correctly positioned, remove or cut away all securing materials, such as rope, plastic, or burlap, from the upper half of the root ball.
Backfill the hole using the native soil that was excavated, gently tamping it down to remove large air pockets. Avoid using excessive soil amendments, as this discourages roots from growing outward into the surrounding native soil. After backfilling, create a shallow berm or ring of soil around the edge of the planting hole to form a water basin, directing irrigation toward the root zone.
Post-Transplant Aftercare and Monitoring
The first six to twelve months following the move are critical for the tree’s survival, requiring consistent attention to moisture levels. Immediately after planting, water the tree deeply and thoroughly to settle the soil and eliminate air pockets. Consistent, deep watering is necessary, especially during the first few weeks, to ensure the root ball remains moist but never waterlogged.
For the first growing season, consistent moisture is the goal, as water stress can significantly decrease growth. Monitor the soil moisture daily using the finger test, watering only when the top inch of soil feels dry. Adding a three to four-inch layer of organic mulch helps retain moisture and regulate temperature, but keep it several inches away from the trunk.
New arborvitae should not be fertilized immediately after transplanting, as this directs energy toward foliage production rather than root establishment. Wait until the following spring or until the tree shows clear signs of established growth before applying a balanced fertilizer. Observe the foliage for signs of stress, such as browning or yellowing needles, which often indicate moisture issues in the root zone.