Experts and BHG readers answer.
Scrawny Holly Bushes
Late winter to early spring is the best time to prune your hollies. While it's best to make the pruning cuts just above a leaf or bud, hollies are quite tolerant of shearing at most any point on the stem. Just prune back the long, errant stems to about the same length as shorter ones. They'll usually branch just below the point where you make the cut.