How to Prune a P.J.M. Rhododendron


P.J.M. rhododendrons are a group of hybrids, the result of a cross between R. mucronulatum and R. minus var. compacta. Slow growing, it can take up to 10 years for a P.J.M. rhododendron to reach its full height of 4 to 6 feet. P.J.M. rhododendrons are evergreen, with bronze foliage in the fall and heavy flowering in mid to late April. Prune the P.J.M. rhododendron immediately after flowering.

Step 1

Prune all dead branches and twigs from the P.J.M. rhododendron.

Step 2

Remove all dead flowers with the pruning shears. Cut the stems back to within 1/2 inch of new growth. If there are no buds on the stem, completely remove it back to its point of origin.

Step 3

Remove any diseased shoots last by cutting them back to a main branch. Don't drop the diseased foliage onto the soil, but bag and dispose of it immediately.

Step 4

Soak your pruning shears in a solution of 1/4 cup of Lysol disinfectant and 2 cups of water. Do not use bleach or alcohol because these materials cause rust on gardening tools.

Tips and Warnings

Things You'll Need

  • Pruning shears
  • Bag
  • Lysol disinfectant


  • University of Connecticut: Rhododendron PJM Hybrids
  • American Rhododendron Society: Pruning and Dead-Heading
  • "‬California Master Gardener Handbook‭"; ‬Dennis R.‭ ‬Pittenger‭; ‬2002
  • Washington State University: Sterilized Pruning Tools: Nuisance or Necessity?
  • University of California: How Disinfectants Compare in Preventing Transmission of Fire Blight
Keywords: prune PJM rhodendrons, trim PJM rhododendrons, pruning flowering shrubs

About this Author

Victoria Hunter has been a freelance writer since 2005, specializing in gardening-related topics and the real estate industry. She is a former broadcaster and real estate agent who has provided audio and written services to small businesses and large corporations worldwide. She writes for, GardenGuides and ProFlowers, among others. Hunter holds a Bachelor of Arts in English/creative writing.