Rhododendron Die Back
I have two rhododendrons that were planted fall 2015. catawbiense grandiflorum. They were doing fine until this summer when branches started dying all the way back to the ground. The plants seem to continue to grow, but then another branch dies. I have been cutting off the dead branches. Should I fertilize them with Holly Tone, or spray them and with what or what else should be done? Also, the plants are in the drip line of the roof of a shed so they get lots of water when it rains. Do I need to put up rain pipes? I have pictures, but I wasn't able to upload them.
Howard County Maryland
Your rhododendron seems to be having difficulty becoming established. It takes years to become firmly established. They have shallow root systems and when there are dry periods, they suffer. Continue to cut off dead branches. Water deeply if there is not an inch of rain in a week and the soil is not frozen. This fall when the deciduous leaves fall and the soil is moist, you can apply Hollytone. Make sure no water stands in the area around the rhododendron. http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG51_IPM_Azaleas_and... vw