I have two patio standard holly trees. One is ordinary holly the other variegated. How and when do I prune them to maintain their shape? I am aiming for a round shape.
Pruning Patio Standard Holly Tree
Certified GKH Gardening Expert
This article will help you with the basics:
Pruning is basically sculpting the plant. If you are aiming for a round shape, then start shaping them that way. If you need to remove more than a few inches to do this, you may want to take a little off this year and then do more next year, shaping the plants gradually.