Prune in late winter or early spring before new growth starts
Remove dead, damaged, diseased, or crossing branches
Cut out suckers from the base
Remove weak, thin, or inward-growing stems
Keep 3 to 5 main trunks for a tree form
Thin crowded branches to improve airflow and light
Cut branches back to a side branch or main trunk
Avoid topping or cutting the tops flat
Do not leave stubs
Use clean, sharp pruning tools
Remove spent flower clusters if desired
Limit pruning to no more than one-third of the plant at a time
Remove low branches if you want a tree shape
Prune lightly each year rather than heavily at once