It appears that my PJM rhodies got some winter burn – the tips of some of the leaves turned brown but are still pliable (not brittle). What can I do about this if anything? Could it be something else? Also, how do I get them to fill in better? This will be the third season they are in the ground and haven’t grown or filled in very much. They normally flower rather well though.
Winter burn is pretty common on rhodos…especially after a windy winter like the one we just had. Those leaves are nipped forever but will be masked by new growth this spring. Any that are totally brown can be removed any time. A burlap barrier on the north west side over winter can help prevent this in the future. It takes a while for shrubs to get established and yours has only been in the ground for 2 seasons so it is still getting settled in. You should feed your rhodos (indeed all your landscape plants) as soon in spring as the ground can be worked (right now). For the rhodos use Espoma Holly-Tone. Pound holes out away from the trunk as far as the outermost branch tips and pour a small handful of food into the hole and poke it shut. Do this in several places around the shrub. Throwing food down on the surface is easier but mostly benefits weeds. Get the food down to the roots and it will work better. Deadheading will also help the PJM fill out and flower more. After the flowers have finished, pinch off the seed pods that begin to develop after the petals fall off. The rhodo will put a great deal of energy into these seeds. By removing the seeds, you are redirecting that energy into leaf growth and flower buds for the next season’s show. You can also do any light pruning right after flowering. If you haven’t been feeding and deadheading try that first. It should be enough to get them to start filling. Try that for a season before you resort to pruning.