Ornamental & Tree Diseases
For the last couple of years I've noticed swollen areas on some of the branches of my loblolly pines. These galls are now 3 or 4 inches in diameter and seem to be growing. In the spring, these enlarged areas are covered with orange material, which disappears after a week or so. Are my trees diseased and in danger of dying?
Yes, you do have a disease, technically referred to as fusiform gall rust. Whether this fungus disease will kill your tree depends primarily on the location of the galls (the swollen areas you referred to). If the gall areas are located on the main trunk of the tree, yes, your tree will eventually die as a result of the disease.
On the other hand, if the gall is on side branch a foot or more away from the trunk, prune the affected branch and save the tree. By the way, the orange material is a stage in the life cycle of the fusiform rust disease. Read all about it in an issue of For more information, read all about it in a Plant Pathology Infobyte: "What's That Orange Stuff on My Pine Tree?"
