Cottonwood trees, known for their rapid growth, are common across North America. As native species, they often establish as volunteer saplings. While transplanting cottonwoods is possible, it requires careful planning and execution for successful establishment.
Why and When to Transplant Cottonwood Trees
People often transplant cottonwood trees to relocate volunteer saplings growing too close to structures or from undesirable spots. Cottonwoods are exceptionally fast-growing, sometimes adding up to 6 feet in height per year. Even small saplings can quickly become too large to manage.
The optimal time for transplanting cottonwood trees is during their dormancy, typically late autumn after leaves drop or early spring before bud break. Transplanting during dormancy minimizes stress, allowing the tree to focus energy on root establishment. While other times are possible, the dormant season generally offers the best chance for success.
Preparing for Cottonwood Transplant
Thorough preparation of both the new site and the cottonwood itself is crucial for successful transplanting.
Selecting the New Site
Choosing an appropriate new location is fundamental. Cottonwoods thrive in full sun, requiring at least six hours of direct sunlight daily. They prefer moist, well-draining soils, often found along riverbanks or floodplains. The site must provide ample space for the tree’s mature size, as cottonwoods can grow 70 to 100 feet tall with a 50 to 70-foot spread. Their extensive root systems can damage nearby structures, sidewalks, or septic systems, so careful placement away from these elements is important.
Preparing the Tree
Thoroughly water the cottonwood a few days before transplanting to moisten the soil around its roots. This helps the root ball hold together during excavation, reducing damage. For larger specimens, root pruning several months in advance can promote a more compact root ball, which is beneficial for transplanting. This involves severing roots around the tree to encourage new feeder roots closer to the trunk.
The Cottonwood Transplant Process
Moving a cottonwood tree requires careful handling and precision to preserve the root system and minimize transplant shock.
Digging the Root Ball
Water the tree thoroughly the day before digging to moisten the soil. Dig a trench around the tree, creating a root ball sized for the trunk diameter. A guideline suggests a root ball diameter of 10-12 inches for every inch of trunk caliper. Carefully sever the roots with a sharp spade, pushing it inward under the plant to lift it while keeping the root ball intact. For smaller saplings, the root ball should be deep and wide enough to encompass a significant portion of the root system.
Moving and Handling
Once the root ball is separated, gently lift and transport the tree. For smaller trees, use burlap or a tarp to wrap and support the root ball, preventing it from breaking apart. For larger trees, specialized equipment like a wheelbarrow or large container may be necessary. Avoid carrying the tree by its trunk; instead, support the root ball itself.
Planting the Tree
Prepare the new planting hole to be twice as wide as the root ball and just as deep. Place the cottonwood in the hole, ensuring the top of the root ball is level with or slightly above the surrounding ground surface to prevent stem rot. Backfill the hole with the original soil, gently packing it around the root ball to remove air pockets. Immediately after planting, water the tree generously to settle the soil and eliminate air pockets.
Aftercare for Transplanted Cottonwoods
Consistent aftercare is necessary to help the cottonwood establish and thrive. Proper watering, mulching, and monitoring are key to its recovery.
Newly planted cottonwoods require regular watering, especially during dry periods, to support root establishment. Daily watering for the first one to two weeks post-planting is often recommended, transitioning to every two to three days for the next few months, then weekly until roots are fully established. Generally, 1 to 1.5 gallons per inch of stem caliper at each watering is a good starting point. Creating a circular soil mound around the root zone can help direct water to the roots.
Applying organic mulch around the tree’s base helps conserve soil moisture and regulate soil temperature. Spread mulch a few inches away from the trunk to prevent moisture buildup against the bark. If the new site is exposed to strong winds, temporary staking may provide stability until the root system anchors the tree. Ensure ties are loose enough to prevent girdling the trunk.
Challenges and Considerations
Transplanting cottonwood trees, especially larger specimens, presents distinct challenges. They have extensive, often shallow root systems that spread rapidly, making excavation of an intact root ball difficult and increasing damage risk.
Cottonwoods are among North America’s fastest-growing trees, adding 6 feet or more in height annually. This rapid growth means a small sapling can quickly outgrow a manageable transplant size. For anything beyond very young saplings (typically less than 2 inches in trunk diameter or under 8 feet tall), successful transplanting significantly decreases. Professional tree moving services with specialized equipment are often necessary for larger trees, but success rates are not guaranteed, and mortality can be high. Cottonwood wood is also weak and brittle, prone to limb breakage, which is an important consideration for long-term placement.