An overgrown holly (Ilex spp.), either on its own or part of a hedge, can loom over the garden, looking rangy at the base, while casting shade where you don't want it, or blocking doors or windows when used as a foundation shrub. Restore a holly that has outgrown its planting area, or has begun to look bedraggled and unattractive through drastic pruning. Rejuvenate your holly with one of several renovation pruning techniques, depending on how much of the plant you want to maintain during the process and the final form you want your holly to take.
Spray the blades of your pruning tools with household antiseptic cleaning fluid to kill any lingering plant disease or fungal spores from recently pruned plants. Dry the blades with a paper towel.
Prune away one-third of the oldest, longest stems of globe-shaped hollies in the early spring, just as new growth begins. Cut branches with loppers or a pruning saw depending on the diameter of each. Repeat each year for three years to renew growth and reduce height gradually to avoid a visual hole in the landscape.
Cut off all the branches of a mispruned holly hedge or single specimen back to either 3 to 4 inches, tall or to 6 inches shorter than your desired height for the plant. Thin crossing or too-congested growth as the plant fills in, and pinch or cut back the growing tips every time they put on 6 inches for dense growth starting at the base of the shrub.
Cut back the branches up one side of a vertical holly hedge when you don't want to lose it as a screen. Remove each branch back to within a few inches of the main trunk, cutting shorter at the top and longer as you move toward the base to maintain the natural shape of the holly. Hollies can push out growth even from old wood. Trim the other side of the shrub back to one-third of their length. Cut the unrenovated side back in the second year.
Remove branches at the bottom of a single-trunked holly to a point one-third of the way up the trunk to create a tree-form holly. Cut with loppers or a pruning saw just outside the branch collar -- the raised ridge at the joint between the trunk and the branch. Thin crossing, too-long, spindly and congested growth from the remaining crown. Remove any shoots or other lower branches until the bottom of the crown is at your desired height the following year.
Things You Will Need
- Bypass pruners
- Pruning loppers
- Pruning saw
- Household antiseptic cleaner
- Paper towels
- When retraining hedges, cut them so they are at least 6 inches wider at the bottom of the plant than the top, so all parts get sun and remain full.
- Hand pruners cut stems up to 1/2 inch thick, loppers handle branches up to 1 1/2 inches in diameter, while you should use a tree saw for any larger branches.
- Most holly species are hardy from U.S. Department of Agriculture plant hardiness zones 5 through 8 or 9.
- Don't attempt to cut branches while standing on a ladder. Use a pole saw or hire a professional arborist.