An occasional problem of oaks has showed up more often than normal this spring. You or your clients may notice oak leaves that have little or no blade surrounding the main veins, resulting in a skeletal appearance more reminiscent of an asparagus leaf than an oak leaf. Frequently, this damage is mistakenly attributed to leaf-chewing insects.
The name given to this phenomenon is "oak tatters." The damage appears to be caused at or before the time of bud break. The cause of oak tatters is not well understood, however. Similar damage to leaves of other tree species in the northeast U.S. has been attributed to insects called pear psyllids, which apparently can damage leaf tissue by feeding on buds. Whether oak tatters is caused by psyllids, by cold injury, and/or by some other mechanism remains a mystery.
Like the cold injury described above, however, oak tatters seems to cause no lasting injury to trees. Its appearance in a particular tree during one year does not imply that it will reappear in a subsequent year. Even when it is present, the damage appears to be esthetic rather than fundamental.
This article originally appeared in the June 9, 1995 issue, p. 84.