I HAVE AN OLD BUSH THAT GROWS WELL. I DO NOT WANT IT TO GROW HIGHER AND WANT IT TO FLOWER THIS SPRING . IF I CUT THE NEW GROWTH WHICH FOLLOWS THE FLOWERS, I WILL PREVENT THE BUSH FROM GROWING HIGHER, BUT WILL NEW BUDS FORM DURING THE SUMMER AT A LOWER LEVEL ?
Mature rhododendron need little pruning beyond shaping, as well as, to remove dead or diseased wood. Generally prune right after flowering and do not remove more than 1/4 of the shrub. You can remove spent flower heads. Be careful not to damage the growth buds at the base of each flower stalk.
If you prune back to the main trunk, flowering will be delayed but if you prune back to a branch the plant should flower next season.