Oak Tatters

I have an oak tree in my yard that gets oak tatters every year. I have had a couple oak samples brought into the office with the condition this year, so know it is more widespread than my backyard. If your oak tree looks like something ate up the leaves back to the veins, read on.

Oak tatters has been happening for the past few years in Illinois. Nancy Pataky, Director of the University of Illinois Plant Clinic, says, " I have seen the problem on oaks, particularly those in the white oak family." Nancy provides the following information about oak tatters.

The symptoms are quite bizarre. Much of the leaf is just gone. The tissue that remains is the vein tissue and a bit of leaf blade around the veins. Leaves appear to have been eaten by a voracious insect that prefers non-vein tissues. The edges of the leaf that remain are often brown or thickened like a callous tissue. Some refer to this as oak tatters. Others call it bare bones or oak skeletonizing.

What is the cause of this condition? We don't know for certain, but it appears to be the result of cold injury when the leaves were still in the bud. Look closely at the leaves. The injury appears to be nearly symmetrical, as is often the case with injury that occurred in the bud. Because the injury is so bizarre, many think that herbicides are involved. In all cases where other plant materials are growing nearby, only the oaks are affected, and sometimes one oak is affected, while nearby oaks do not show symptoms. Herbicides probably would not be so discerning. There is still much speculation that herbicides are part of the story. Anthracnose is not to blame for this condition, although anthracnose fungi might also be present.

On my tree, the leaves seemed affected early on, and then new leaves emerged and more or less hid the affected leaves from view. In other words, the trees recovered. I have many oaks on my property, but only one tree has these symptoms. It has had the symptoms three of the past four years.

What do we suggest for action by the homeowner? Try to improve tree vitality so that the tree can continue to produce new leaves. Usually this means watering the tree in periods of drought, removing dead wood, and fertilizing with a general tree fertilizer in the fall. If you have a healthy old oak tree with these symptoms, leave it alone. We will keep you posted as we learn more about this condition.