What do you mean when you say your Harry Lauder wants to be real tree, Barbara? Clipping of the top of the tallest stems will stop their vertical growth and encourage branching. If, however, you want to develop your Harry Lauder as a standard, you will need to prune it in stages, making sure you don't remove too many lower branches at a time if that is where most of the leaves are. Prune after the plant has bloomed and made its first flush of growth, late spring-early summer.
Many of the Harry Lauders Ii've seen look more like a large bush than a tree. As a bush ours has outgrown its space and is encroaching upon a walkway. I was hoping that we could trim it in such a way as to encourage it to go up more than out. What do you mean ,as a standard? Thanks for your help.
Barbara, a standard is when a plant has a single trunk up to a certain height and then it branches out, you have probably seen rosemary trained this way, PG hydrangeas and others. Follow Doug's advice and remember to do it in stages. I would not prune more than 1/3 of the total plant at one time. Good luck!
That kind of cosmetic pruning can be done any time..I really like to prune Contorted Filbert while it has leaves..have added a couple of photos of one I tackled this summer...
Often when this plant starts looking like a tree, it is because the branches from the original plant are allowed to grow. These are the straight branches, not the twisty ones. If this is the case, these must be pruned off as soon as you notice them or they can take over your lovely plant. If you need to prune the contorted branches, do so very selectively.
Some cultivars seem to be more prone to setting side shoots than others. That does give them a more "tree-like" shape. The trick to keep them in shape seems to be to cut them back severely about every third year. You can remove side shoots and cut back one or two canes to the ground. Be sure to let all the "flower arrangers" you know know when you plant to cut it back so they can have the stems for their floral designs. Sometimes local florists will even pay for the "trimmings".
Don't do any pruning until late winter or early spring so water won't enter the fresh cut surface and cause damage if it freezes, always make the cuts as vertical as possible for the same reasons.