A young lemon tree will produce new shoots below the area where it was grafted. These shoots are known as suckers because they will suck energy from the young tree. They are easy to locate; they'll generally look different from the shoots above the graft. Sometimes they are thornier, and the leaves will look different than those above the graft. It is important to remove suckers as soon as they appear. Luckily, removal is easy.
Mix together 1/2 cup of disinfectant cleaner and 2 1/2 cups of water.
Place the pruning shears into a shallow tub or pan and cover them with the disinfectant cleaner/water solution. Allow them to soak in the cleaner for three minutes. Rinse them well under clear, running water and allow them to dry prior to using.
Locate the graft joint on the lemon tree. This is the area where the tree was originally grafted onto the rootstock. Look for a swollen area on the lower 1 to 2 feet of the trunk.
Remove any growth that is sprouting below the graft joint. Using the hand pruners, snip them off as close to the tree as possible. Use a vertical cut so the moisture will run away from the cut.