Transplanting a tree involves moving an established plant, a high-risk process requiring meticulous planning. A large, established tree can lose up to 90% of its root system during the move, causing severe physiological stress known as transplant shock. This shock results from the tree’s inability to absorb enough water and nutrients through its reduced root mass to support the existing canopy. Successful relocation depends on precise execution and dedicated care, starting well before the move.
Selecting the Best Time and Preparing the Roots
Transplanting should occur during the tree’s dormant period, typically in late fall after leaf drop or in early spring before buds swell. Moving a dormant tree significantly reduces its metabolic demands for water and nutrients, minimizing stress from root loss. This timing allows the tree to focus energy on root regeneration within the soil ball before the demands of leaf-out and summer heat begin.
Root pruning should be performed several months to a year prior to the transplant to condition the tree. This preparatory step involves using a sharp spade to cut a circular trench around the tree at the diameter of the future root ball. Severing lateral roots encourages the tree to produce a dense network of fine, fibrous feeder roots closer to the trunk. This concentrated mass of new feeder roots, contained within the excavated soil ball, enhances the tree’s ability to absorb moisture once replanted.
Excavating and Protecting the Root Ball
The removal process must focus on retaining the intact root ball, as this soil mass contains the roots responsible for water and nutrient uptake. Root ball size is determined by the tree’s caliper, measured six inches above the soil line. A guideline is to plan for a root ball diameter 10 to 12 inches wide for every one inch of trunk caliper.
Excavation should proceed by cutting cleanly around the measured diameter with a sharp spade, ensuring smooth edges and cleanly severed roots. The ball’s depth is typically one-half to two-thirds of the diameter, focusing on the upper soil layers where feeder roots concentrate. Once undercut and separated, the root ball must be immediately secured to prevent cracking or drying out.
Wrapping the soil ball tightly in burlap, a specialized container, or a wire basket provides structural integrity for lifting and transport. The securing material, such as twine or rope, must be pulled taut across the top and sides to maintain soil-to-root contact. Immediate containment of the undisturbed soil mass is necessary because fine feeder roots die rapidly upon exposure to air and light.
Replanting Techniques for Survival
The new planting hole should be prepared before the tree arrives, making it two to three times wider than the root ball but no deeper. The soil at the bottom must remain firm and undisturbed to prevent the root ball from settling, which compromises proper planting depth. During replanting, ensure the root flare—the widening where the trunk transitions into the roots—sits at or slightly above the finished soil grade.
Planting the tree too deep is a common mistake, as it deprives surface roots of oxygen and can lead to trunk tissue decay. Once positioned, backfilling should begin with the original soil, avoiding excessive amendments that discourage roots from growing outward. The soil should be gently tamped to remove large air pockets, but not excessively compacted, as this restricts water infiltration and root growth. After the backfill is complete, the burlap and any ropes or wires around the top third of the root ball should be cut away and removed, allowing new roots to spread freely.
Immediate Post-Transplant Care
Immediate post-transplant care helps the tree overcome root loss and establish itself in its new location. Watering is essential, as the tree’s reduced root system cannot efficiently draw moisture from the soil. The tree must be watered deeply immediately after planting, maintaining a consistent schedule of deep, slow watering throughout the first growing season.
Monitoring the soil moisture is important, ensuring the root ball remains moist but never waterlogged, as excessive water can lead to root rot. Applying a two to four-inch layer of organic mulch, such as wood chips, helps retain soil moisture and moderate temperature fluctuations. Keep the mulch several inches away from the trunk and root flare to prevent moisture buildup against the bark, which encourages disease and decay. Staking should only be used if the tree is unstable, using flexible ties that allow movement to encourage trunk strength, and supports must be removed after one year.