Root Self Exam

Few tree failures are as tragic as ones caused by girdling roots. This condition, caused by roots that have circled the main trunk growing to eventually strangle the tree, results in a slow decline and eventual death of trees in their prime.
This condition can occur with a wide variety of trees, maples, cherries, plums and pines are a few on the ones I have personally observed in the last few months.
Normal root systems extend from the root flare at the base of the main stem and move away from the stem like the spokes of a bicycle wheel. The roots that cause trouble, circle around the tree and constrict the main stem. Tree roots that cross other roots further away from the main stem cause little damage and my even form unions or grafts that result in no damage at all.
If you let the girdling roots go unchecked they will eventually cause the tree to die back and decline to the point of failure.
Fortunately you can easily observe tell tale signs that are indicative of root problems on your own trees.
Trees should have a basal flare where the main stem meets the soil surface. This sometimes pronounced swelling should lead from main stem to root in smooth curve.
Flattening of one side of the stem can indicate a buried root that is pressing on the main stem and causing stress on the trees vascular system. The root actually compresses the tissues of the tree preventing the movement of water up the stem and nutrients down to the roots. You may even see decline on that side of the tree. Small leaves and reduced growth on one or more sides is another typical symptom. If you are able, grasp the tree and slowly shake or try to move it, it should be firm and not rotate. Small trees with girdling roots will move like the stick shift in a manual car.
Occasionally, the tree will not display any outward obvious symptoms yet will fail when extreme weather conditions overwhelm the trees circulatory system. Periods of drought or extreme heat can result in this type of failure. Once the tree has failed a close examination will reveal the obvious signs of girdling roots. Take a look for these telltale signs:

Large roots that are visibly crossing the trunk of the tree
Lack of typical root flare on one or more sides of the tree
Yellow or smaller leaves on one side of a tree
Recessed, inverted or flattened root flares that curve inward like the point of a pencil
Instability in small trees when manually shaken or pushed

I.S.A.Certified Arborists are knowledgeable in identifying and correcting girdling root problems. Take the time to consult with your Certified Arborist if you suspect your tree has rooting problems. You may be able to limit the damage caused by girdling roots and prolong the life of your tree.