Properly trimming back overgrown holly trees is necessary to encourage new growth on the holly tree and provide more berries, especially important in young holly trees. Basic trimming methods are important to know and understand before trimming your holly tree. A proper pruning gets rid of old growth to make way for sunshine to get to new growth and mature different parts of the tree. Use the lopper to get rid of the thickest branches, and pruning shears for the thinner branches and twigs.
Put on the gloves and protective eyewear. Prune the holly tree during the months of February to April, before new growth starts. Take a look at the ground and base of the holly tree. If there are any growing branches within 4 feet that are coming up out of the ground, around the base or from the bottom sides of the tree, trim these off with the pruning shears.
Examine the lower trunk area of the holly tree to make sure it appears healthy with no insect infestation. It is also important to look for wounds or holes that could represent disease. Some problems can be fixed with natural remedies or pesticides, but more serious problems call for the holly tree to be cut down and extracted from the ground.
Trim back holly branches growing in a downward manner past the lowest normal branches of the holly tree. Trim these close back to the trunk of the tree, but do not cut into the tree.
Use a ladder to climb up the holly tree to get eye-level with the middle section of larger mature holly trees. Use the pruning shears to trim away the weakest-looking branches that seem in the way, or are overcrowding. The point is to create extra space to let sunshine through to help develop other, younger parts.
Trim away any branches growing upward or awkwardly that may collide with stronger branches.
Cut away bent or broken branches, damaged branches and scar tissue growth. Sometimes, it is smart to trim characteristics such as criss-crossing branches or narrow crotches so they do not choke out other growth.
Examine the holly tree once you've pruned it back. It should appear as an oval or scaffold shape.
Always be cautious with sharp shears or working from atop a ladder.