What Is A PJM Plant?
What Is A PJM Plant? PJM Group is a series of rhododendron hybrids that resulted from crosses between R. carolinianum and R. dauricum var. sempervirens. These hybrids are compact, rounded, small-leaved, evergreen shrubs that generally grow to 3-6′ tall and are noted for having exceptional winter hardiness. What does PJM stand for in PJM rhododendron?