Sycamore trees are a common sight across the UK. They are often considered of little or no value for wood lots or other wooded areas. Girdling is an effective way to kill a sycamore tree, as it cuts off the tree's sap, which is necessary for it to live. This method is safe and effective and requires only the use of an axe. Subsequent treatment of the girdled area with herbicide will prevent the tree from putting forth new shoots. This latter method is best for trees in locations away from inhabited areas.
Cut into the tree, angling the cut downward to remove the bark as well as the portion of the tree directly under the bark. The cut needs to be at least 1.3 cm (1/2 inch) deep on smaller trees and as much as 4 cm (1 1/2 inch) deep for larger trees.
Chop out a section of bark and tree about the width of the axe and the appropriate depth for the size of the tree. The section should be about 7.5 to 10 cm (3 to 4 inches) from top to bottom. Remove this section completely.
Repeat this process all the way around the tree. The number of cuts required will depend on the size of the tree.
Check to make sure that the cuts overlap one another so there is no bark or surface wood left anywhere in the girdled area. Sap can flow through areas where the cuts are not deep enough or the wood has not been completely removed, in which case the tree will not die.
Spray the girdled area with herbicide. Wear protective gear to prevent ingesting or touching the herbicide with bare skin. Follow the manufacturer's instructions for use. The girdling kills the tree, and the herbicide prevents new growth.
Girdling the tree before spring will prevent new growth from starting, resulting in less mess when the tree dies. Girdling can be done at any height on the trunk, so cut at a height that is most convenient for you.
An axe can be dangerous. Use extreme caution. Do not allow children or pets in the area when the axe is being used. Branches can be loosened by the vibration of the axe on the tree. Wear a hard hat to prevent injury. Herbicide is poison. Follow manufacturer's instructions for proper handling. Spray bottles used to apply herbicide should be clearly labelled as to their contents. Dead trees become brittle over time and will eventually break and fall. If the sycamore is not in a safe location away from inhabited areas, it should be removed by professionals as soon as it is practical.