My two rhodies [anah kruschke] are at the end of a bed and jut our just beyond two tree trunks [1-1 1/2' -one cherry and the other maple] just up to the point where there is a slope down to the street. Unfortunately the prevailing wind pattern goes against the side of the tree trunks that they are on [and we can have hard winter winds]. They have been struggling the last two years. We are wondering if we should replace them. Do you all think a different variety of rhododendrun like Lee's dark purple or PJM lavender would be better?