Monday, December 12, 2011

Sample of the Week: Girdling on Arizona Cypress

Notice constricted base (Photo: Jennifer Pries)
This week we received an Arizona cypress that had died back rapidly in the fall. Nearby trees were unaffected and the client suspected that the lower stem might have been damaged by voles. However, Dr. Hodges, our tree diagnostician, found constriction at the lower stem (trunk) but could not find evidence of vole damage. Upon further examination, Dr. Hodges concluded that a root had grown around the base of the stem, girdling the tree. Root girdling occurs when the roots of the plant grow around the base or main stem of the tree causing restricted water and nutrient movement. Growth slows down, leaf production decreases and eventually, the tree will begin to die back.
Notice roots curling around base (Photo: Jennifer Pries)
Planting trees too deep or mulching too high around the tree can promote root growth around the base of the tree. Trees grown in container nurseries are more prone to root girdling because the roots are forced to grow in a circular fashion in the pots. Proper pruning of the roots in the nursery and before transplanting can significantly reduce the potential for root girdling in future.

For more information on proper transplating, click here
For more information on root girdling, click here