A: It’s a tough problem.
By and large, most evergreen shrubs don’t respond well to that level of extreme pruning. Dwarf Burford hollies are quite tough and should recover over time. But that process could take years before you have a hedgerow that looks like something you’d want in your front yard! The general rule of thumb we recommend is to prune no more than 15-20% off your hedgerows at a time. If you’re cutting your hollies back halfway, it’s only going to have a scattering of leaves left when you’re done.
Your realistic choices are:
• Replace the hedgerow. Even using the same species of plant – dwarf Burford holly is a vigorous and hardy plant. Young, 3-gallon plantings will look good immediately and fill in faster than whacking back a row that’s so overgrown. 7-gallon sized plants will speed this process up by close to a year.
• Accept some encroachment in the short term. Pruning the row back that 20% or so will give you a much better appearance and free up a lot of the sidewalk space, even if it doesn’t clear it entirely. The plants will look a lot better pruned back this far instead of halfway.
• If replacing the plants is too labor intensive or expensive for now and the encroachment has reached unacceptable levels, wait until early February before giving the plants that heavy cut. The spring flush of growth will help fill in some of the worst “bad haircut” look as soon as possible afterwards if pruned then. This is not our preferred method, but it’s the best way to do this if necessary.