Arborvitae, members of the Thuja genus, are popular evergreens due to their dense, attractive foliage. Moving an established arborvitae can be done successfully, but the plant’s shallow, fibrous root system makes it susceptible to transplant shock if not handled with care. This process requires precise timing, careful execution, and dedicated aftercare to ensure the long-term health and establishment of the shrub in its new location.
Timing and Preparation of the Arborvitae
The ideal periods for transplanting arborvitae are late summer through early fall (late August to early November) or in early spring before new growth begins. Moving the plant during these cooler periods minimizes water loss stress and allows roots to establish while the plant’s above-ground growth is slowed. Avoid transplanting during the heat of mid-summer, as high temperatures and intense sunlight quickly lead to severe desiccation and transplant shock.
For larger, established arborvitae, root pruning can significantly improve survival chances. This technique involves using a sharp spade to cut a circle around the shrub several months before the move, effectively severing the longer roots. This forces the plant to develop a denser mass of fine feeder roots closer to the trunk, which will be contained within the eventual root ball and enhance water absorption post-transplant.
The arborvitae requires deep hydration in the days leading up to the move. Saturating the soil thoroughly 24 to 48 hours before digging ensures the plant is fully hydrated, counteracting inevitable water loss. Pre-watering also helps the soil adhere firmly to the roots, maintaining the integrity of the root ball during excavation, and the new planting site should be fully prepared to reduce root exposure time.
Excavating the Root Ball and Moving the Shrub
Determining the correct root ball size is essential, as this mass contains the majority of the fine feeder roots necessary for survival. A general guideline is to aim for a root ball diameter of 10 to 12 inches for every one inch of the trunk’s caliper, measured six inches above the soil line. For example, a two-inch caliper arborvitae requires a root ball approximately 20 to 24 inches in diameter, with sufficient depth to capture the shallow, spreading root system.
To begin excavation, use a sharp, straight-edged spade to cut cleanly down into the soil along the determined circumference. This trenching action severs the long lateral roots with minimal tearing, creating a distinct boundary for the root ball. Once the perimeter is cut, the most challenging step is undercutting the root ball to sever the deeper taproots and anchor roots.
Work the spade horizontally beneath the root ball, or use a root saw, to cut the base free, carefully rocking the shrub to sever remaining connections. Keep the root ball as intact as possible, as crumbling results in the loss of valuable feeder roots. Immediately slide heavy-duty burlap or a tarp beneath the ball, lifting the plant by the root ball itself, not the trunk, to prevent the trunk from separating from its root system. Secure the burlap tightly around the entire ball with twine or rope to maintain its shape and moisture during transportation.
Replanting in the New Location
The planting hole must be prepared to encourage lateral root growth into the surrounding native soil. Dig the hole two to three times wider than the root ball’s diameter, creating a wide shelf for new root expansion. The depth must be precise so the root ball sits no deeper than it did originally, ensuring the root flare is visible and level with or slightly above the surrounding grade after planting.
Carefully set the arborvitae into the prepared hole, maneuvering the heavy root ball into position using the secured burlap or tarp. Once oriented, all wire baskets, ropes, and any synthetic burlap material must be completely removed. If using natural burlap, cut it away from the top third of the root ball and fold it down into the hole, ensuring no burlap remains above the soil line to wick moisture away from the roots.
Begin backfilling the hole with the native soil, avoiding excessive amendments that discourage roots from growing beyond the planting area. Gently tamp the soil as you go to eliminate large air pockets. Once the hole is filled, use the remaining soil to construct a small, circular berm or watering ring just outside the root ball perimeter. This earthen dam contains water over the root zone, directing moisture inward.
Critical Aftercare for Transplant Success
Immediate and deep watering is the first step in successful aftercare, settling the soil around the roots and eliminating air pockets. The newly transplanted arborvitae needs a thorough soaking immediately after backfilling and watering ring construction are complete. This initial watering must penetrate the entire root ball and the surrounding backfill soil.
A consistent watering schedule is necessary for the first year to minimize transplant shock and encourage new root growth. For the first few months, the plant requires deep watering two to three times a week, ensuring the soil remains consistently moist but never waterlogged. As the plant establishes itself, gradually reduce the frequency, checking soil moisture regularly, especially during dry spells.
Applying a two to three-inch layer of organic mulch, such as wood chips or shredded bark, over the entire planting area helps to conserve soil moisture and regulate soil temperature. Keep the mulch pulled back several inches from the trunk flare itself, preventing it from physically touching the bark. This avoids the “mulch volcano” effect, which can trap excessive moisture against the trunk, creating an environment favorable for disease and pest entry. Continue monitoring the foliage closely for signs of browning or needle drop, which are indicators of water stress, and adjust the watering schedule as needed throughout the first growing season.