A new client has some old, gangly, never pruned, rhododendrons that miraculously still bloom every Spring. Will rejuvenation pruning kill them? When should I prune?
Extension
Message
From:
Richard Hentschel
Extension Educator, Horticulture
DuPage/Kane/Kendall Unit hentsche@illinois.edu
I would suggest renewal pruning along with fertilization to encourage new growth as the plants are quite old according to your description. Renewal pruning will take 2-3 years to complete, yet you do not run the risk of killing the Rhododendrons.
