· Brooks Wilson's Answer
Late February, early March is the optimum time to perform heavy pruning on a Ligustrum. Ligustrum takes heavy pruning well. If a tree form Ligustrum has long and leggy branches and has a shaggy appearance it can be pruned quite drastically. Prune back the bushy top of the Ligustrum by 20 to 50%. If the Ligustrum is large in size and the branching is of heavy caliper a long handled by-pass lopper will be necessary. If the Ligustrum is smaller sized and the branching is relatively small in caliper a pair of hand pruners should do the trick.
Visualize the preferred size and shape desired and begin making cuts to achieve the preferred result. There's not really any major rules for pruning Ligustrum. Even though the plant may look a little skimpy and bare after pruning, don't worry. With the warmer season just ahead new foliage will emerge. Let the new growth come out to about 1-2 feet and prune it back about half way. Continue to do this until the preferred size is achieved. Regular pruning will be necessary to keep the desired size and shape. Ligustrum is a fast growing plant and can become over grown quickly.
Hope this helps you.