Q. Good morning. A year ago my wife bought two-birch trees. They looked great until now. One seems to be healthy; one has lost all its leaves. They just dried up and dropped. HELP! George Simmons – Tacoma, WA
A. You have not indicated that there are any extenuating circumstances or differences in the care of the two birch trees so I will assume that the care has been the same. Without seeing the two trees in question I can only guess that it could be what I call a congenital defect. Often trees and shrubs are left too long in a small container as they are developing. This causes roots to cross back over themselves in a circular pattern around the trunk. The problem does not become apparent until the tree gets bigger and it girdles (strangles) itself cutting off food and water to the tree. The result could be what you are seeing. I call this congenital since it is not a genetic defect but rather a defect that arises during the development of the tree. It is hard to detect as many trees and shrubs are potted up several times before they are sold. So a tree may not look rootbound in the container but may have been in the past setting up the pattern. Also not every tree or shrub that is left too long in a container will strangle itself. The only way to know for certain is to excavate the soil around the base of the tree too look for signs of strangulation. You will see a root that encircles the trunk of the plant below the soil surface. Also materials left behind like nylon chord holding burlap can also girdle the tree. It is always a good idea to examing the rootball of trees and shrubs before planting and look for and remove roots that are circling the trunk and remove other objects that can interfere with the trees development.