Q. I have a neglected privet that has overgrown its space. When and how far back should I prune it and keep its shape? My neighbor cut one back several years ago and it never came back at all. Thanks.
A. I may have some bad news for you. I looked at the picture and I am guessing most of the leafy growth is out towards the edges of the plant and on the inside will be bare branches.
If your pruning cuts are made back to the inside of this plant where there is no leafy growth, re-growth from these cuts will be either slow or they won't regrow. Regardless, this plant is going to look bad for a long time after these pruning cuts are made.
This is really a case where you have a plant that was just too largeat maturity placed in a spot that was just too small.
Really your best alternative will be to replace it if you want to look nice. It is possible to make some deep cuts and it may regrow but these cuts will have to be done just to the outside of some buds and done very carefully