Tree suckers are small, thin twigs that emerge from the base of a tree trunk, or sometimes directly from the soil under the tree. These suckers should be removed to tidy up the tree and in the case of a citrus tree, to prevent nonfruit-bearing branches from stealing nutrients. Since tree suckers often begin to regrow later, you can apply specialised horticultural products to stop the regrowth from occurring.
Look at the trunk of the tree near the base at the ground and identify any small branches or twigs that are emerging from it, which are the suckers. Cut the suckers off as close to the trunk as possible using hand pruners and making the cut straight across the sucker. Do not damage the main trunk as you cut.
Look at the ground under the tree for small twigs that are growing up from the ground. These are root suckers and can be removed by digging down with a shovel until you locate the main horizontal roots they are growing from. Then cut the suckers off as close to the main roots as possible with the hand pruners.
Open a bottle of sucker-stop liquid, which is available at home improvement stores and garden supply stores. Dip a paintbrush into the mixture and apply a thin coat to every area that you pruned to stop the suckers from growing back.
Although the sucker-stop solution will prevent the removed suckers from growing back, the tree may produce new suckers in other locations.