A couple of weeks ago, we told you about a magnificent, ancient bur oak that was suddenly defoliated overnight. We said that it would recover quickly and that we would update you. With 10 days of mild weather, the tree has leafed out very quickly. Most trees maintain large reserves of starch and protein in their stems, and they can quickly mobilize the stored material to make new leaves. Here are a couple of before and after pictures. The upper picture is the tree on May 21, right after it was defoliated. The lower picture is the same tree on May 31, showing how quickly the tree has leafed out. We still haven’t found the culprit, but this old tree does not seem to have suffered from early spring defoliation.
You may recognize the bur oak in this page from previous photos. It is a magnificent, ancient bur oak in Kirklevington Park. I visit it often. Last week I was looking at the tree in the late afternoon and noticed a few leaf fragments on the ground. The next morning, I came back and saw that the tree had been totally defoliated overnight, stripped of nearly every leaf. After a few days, it began to refoliate – to produce a new crown of leaves. Spring defoliation is very common, but is not very harmful to hardwood trees.
None of the nearby bur oaks were defoliated. Two Shumard oaks had lost a little bit of foliage. It was like a special forces strike on a single tree. Remarkably, the defoliating insects were completely gone by morning, not a sign of them. I don’t know what they were.
We’ll add more pictures as recovery continues.
Click pictures to enlarge or for a slide show.