The sycamore tree, including the native American sycamore (Platanus occidentalis) and the hybrid London planetree (Platanus × acerifolia), is known for its rapid growth and large size. These trees can reach heights of 75 to 100 feet and develop a widespread, aggressive root system. This root system can damage nearby infrastructure like sidewalks and foundations. Because sycamores resprout vigorously after being cut down, homeowners often seek permanent solutions to stop their growth. Successfully eliminating a sycamore requires a multi-step approach that targets the root system to prevent inevitable regrowth.
Physical Removal of Young Trees and Sprouts
Controlling sycamore growth begins with the physical removal of young plants, which avoids chemical intervention. Seedlings and small saplings, typically less than an inch in diameter, are best managed by removing the entire root structure. Hand-pulling is effective for very young sycamores, especially when the soil is moist, allowing the whole root to be extracted cleanly.
For slightly larger saplings, use a shovel or weed wrench to dig out the root ball completely. Sycamores have a strong capacity for vegetative reproduction, meaning any root fragment left behind can send up new suckers. Thorough excavation is necessary because removing the entire root system depletes stored carbohydrate reserves, preventing the plant from drawing on this energy source for future regrowth.
Girdling Established Trees
For a larger, established tree that needs to be killed without herbicides, the technique of girdling can be employed. Girdling involves cutting a continuous band around the trunk’s circumference, penetrating the outer bark and the cambium layer down to the sapwood. This process severs the phloem, which transports sugars from the leaves to the roots. Effectively starving the root system over months or years, the roots die, and the tree will not resprout from the trunk.
Systemic Chemical Treatment for Stumps and Roots
For permanent cessation of growth from an established, cut-down sycamore, applying a systemic chemical treatment directly to the stump is the most reliable method. This introduces herbicide into the tree’s vascular system to kill the root system underground. The most effective active ingredients for this purpose are glyphosate and triclopyr.
The herbicide must be applied immediately after the tree is cut, ideally within 5 to 15 minutes, before the tree seals the wound. For stumps greater than four inches in diameter, concentrate the application on the cambium layer. This thin, lighter-colored ring of living tissue just inside the bark is responsible for transporting the solution to the roots.
Hack-and-Squirt Method
An alternative technique for a standing tree is the “hack-and-squirt” or bark injection method, used on trees over one inch in diameter. This involves making downward-angled cuts around the trunk with a hatchet, penetrating the cambium layer. The herbicide is then squirted directly into these cuts, creating a small cup that holds the chemical.
Chemical treatment is most effective in late summer and fall. During this period, the sycamore naturally moves carbohydrate reserves downward in preparation for dormancy. Applying the systemic herbicide then ensures the chemical is actively translocated along with the sugars, maximizing delivery to the entire root mass.
Long-Term Management of Sycamore Regrowth
Even after successful initial treatment, sycamores often produce persistent regrowth in the form of root suckers and stump sprouts. This regrowth is a stress response, as remaining root fragments draw on stored energy to re-establish a canopy. Managing these sprouts is crucial to ensure the tree’s growth is truly stopped.
The most straightforward non-chemical approach is constant, repeated cutting to exhaust the root system’s energy reserves. Allowing a sucker to grow foliage recharges the root’s energy supply. Therefore, cutting sprouts back to the ground immediately upon appearance prevents this energy replenishment. Although this process may take one or more seasons, the root system will eventually deplete its stored energy and die.
A more targeted solution involves applying a low-concentration systemic herbicide directly to the new suckers. A glyphosate or triclopyr solution can be painted onto fresh cuts or directly onto the foliage, ensuring no overspray reaches desirable plants. Tearing the suckers away from the root rather than simply cutting them can sometimes be more effective, as it removes a greater portion of the basal buds responsible for the regrowth.
If the original stump was not chemically treated, stump grinding removes the visible portion and the main root crown, but it does not eliminate the entire root system. After grinding, the area must be monitored for several seasons. Any residual sprouts must be immediately removed or treated with a targeted herbicide application to prevent the root system from recovering and re-establishing a new tree.