Transplanting a cedar tree (including Cedrus species or related Thuja varieties) is a high-stakes gardening task due to its evergreen nature. Cedars retain their needles year-round, continuously losing water through transpiration, making them highly susceptible to transplant shock. Success depends on meticulous planning and careful execution to minimize root system disruption. Understanding root preparation and timing makes a successful move achievable.
Pre-Transplant Preparation and Timing
The optimal window for moving a cedar tree is during its dormant period, either in late fall or early spring before new growth begins. Transplanting during this time reduces the tree’s metabolic demands, allowing it to focus energy on new root growth. Complete the physical move at least six to eight weeks before extreme summer heat or deep winter freezes.
Preparation should begin six to twelve months prior using root conditioning or pruning. This technique encourages a dense, fibrous root ball close to the trunk, essential for absorbing water and nutrients. Use a sharp spade to cut a vertical trench around the tree, severing the outward-reaching roots in a defined circle.
The root ball diameter is calculated based on the tree’s trunk diameter (caliper), measured six inches above the ground. Use a guideline of 10 to 12 inches of root ball diameter for every one inch of caliper. For example, a three-inch caliper tree needs a root ball diameter of at least 30 to 36 inches. This pruning stimulates feeder roots, improving the tree’s survival rate.
The new planting site requires full sun exposure and deep, well-drained soil, as cedars do not tolerate standing water. Dig the new hole before excavation; it should be two to three times wider than the root ball but only as deep as its height. Plant the tree at the same depth, ensuring the root flare remains visible at or slightly above the finished soil grade.
Executing the Physical Move
On the day of the move, thoroughly water the soil several hours before digging to keep the root ball intact and hydrated. Begin digging just outside the root-pruning line, cutting straight down to sever lateral roots, then working underneath to cut the taproot. Keep the soil surrounding the roots undisturbed to prevent breakage and drying.
Once the root ball is free, immediately wrap it tightly in natural burlap, heavy canvas, or a wire basket if large, securing it with twine. The root ball’s weight is considerable, requiring careful handling to avoid damage. Keep the secured root ball moist during the move.
Set the tree into the prepared hole, ensuring it stands straight and the top of the root ball is level with the surrounding grade. Rotate the tree for the best aesthetic orientation before backfilling with the original excavated soil. Avoid adding amendments like compost or peat moss, as this discourages roots from growing into the native soil.
As you backfill, gently tamp the soil to eliminate large air pockets, and water the hole thoroughly multiple times to help the soil settle. The root flare should be clearly visible above the soil line. Remove all non-biodegradable materials, such as synthetic twine and wire basket components, from the root ball before finishing.
Post-Planting Care for Establishment
The first year after transplanting focuses on establishing a new fine root system, making consistent moisture management essential. Immediately apply a two to four-inch layer of organic mulch, such as wood chips, over the backfilled area. This layer helps regulate soil temperature, reduces water evaporation, and suppresses weeds.
Keep the mulch several inches away from the trunk to prevent moisture buildup, which can lead to bark decay. A consistent watering schedule is vital, typically involving a deep soaking once or twice per week during the first growing season. Apply water slowly using a soaker hose or drip system to penetrate the full depth of the root ball (12 to 18 inches), encouraging deep root growth.
Continue deep watering into the late fall to hydrate the foliage and prevent winter desiccation. Check soil moisture before each watering; the soil should be moist but not waterlogged. If staking is needed for stability, use broad, flexible strapping material anchored low on the trunk for no more than one year.