After an extraordinarily cold winter in Western Washington, many garden owners will want to know what to do about the damage to many of our not-completely-hardy shrubs. With many of our broadleaf evergreens, it’s common for their leaves to turn brown or black and eventually fall off. The plants themselves are probably still alive. To check, use a hand-pruner blade to peel back a little bit of the “skin” to see if the cambium layer just beneath is alive (green) and not dead (brown). If alive, it’ll probably flush out with a new set of leaves. So, don’t panic if your shrub looks dead. Wait and see. How long? By June you will have an answer. By then, those that can put on a new set of leaves will have done so. If you can’t stand the sight of the stricken brown shrub until June, try running your hands along the branches to knock the brown leaves off. Then, the plant might seem to be deciduous, not dead. By the end of August, the final report will be in. Freezing weather sometimes does internal damage that doesn’t show up until after the stress of the summer “drought”. A shrub may look okay through June and July, but then, while it is pumping H2O like crazy trying to keep up with the heat demand in August, some portions can collapse, and you will see die-back. (The non-scientific explanation is my own and may be a little, well, anthropomorphic.) Many evergreen shrubs, such as escallonia, that suffer freeze damage, will die from the tip back. These shrubs respond well to radical size reduction which in this case means big ugly cuts to the point of green wood. The plants will “break bud” just below your cuts and many new green-leafed shoots will rather quickly grow out to hide the cuts and provide you with a “new” plant by the end of the growing season. In the case of choisya, branches will split, break or splay flat to the ground due to snow loading. Get your loppers out and whack everything back to 4” to 6” off the ground. Yes, it’s really Okay. I promise. I have done this thing many times. As soon as the growing season begins, the majority of cut plants will spring into action. As the renovated shrubs grow up, it is advisable to pinch them back every so often, to encourage branching and thicken them up. “Pinching” means a very light heading, just nipping the end bud of each branch with your fingernails or hand-pruners.
Courtesy of PlantAmnesty.