Near the base of the target tree, point hammer down in a copper nail at a slight angle. There is no standard as far as size when choosing copper nails, but usually the more surface of the nail in terms of length and width, the more effective the treatment. Even a longer nail means deeper penetration, resulting in a higher chance of the tree that becomes sick. Further hammer nails in a ring around the tree, about half an inch apart. This will damage an increased number of growth cells and increase the concentration of copper in the tree. This higher concentration is better because this increases the chance of metal oxidation that poisones the tree. The idea that a copper nail will kill a tree only applies to very small trees such as seedlings. Larger trees can tolerate a single nail without any problem and will simply grow over the nail in time without any negative effects. If necessary, cover nail heads with mud? The purpose of covering copper nails with mud is to hide the nails. Copper has a tendency to clearly show the trunk of the trees by its bright colour. Covering the nails makes the process less obvious with a casual look and can preserve the appearance of a yard as the tree starts to die. With mud to cover them, but will not completely hide something has been done on the tree. After the tree is dead, remove the nails before removing the tree. Otherwise the nails could fly and hurt someone, or they could damage the machines that are used to remove the tree as there are many nails.