Question
Oak tree spikey thing
Hi doc! I live in Central Illinois and have a big healthy oak tree in my front yard. Within the past six months to year I have begun to notice these bark colored "balls" forming around the actual branches of the tree. Most are between the size of a quarter and a half dollar and are very hard...just like wood. Very recently I was shocked to see that they started sprouting spikes!! I have tried to find out what they are online but have had no luck thus far. Any ideas what these might be? As of now they do not appear to be harming the tree any.
AnswerBen:
These swellings (galls) are caused by an very small insect called a gall wasp. The gall is called a horned oak gall. Go to Google Images and search for the images of these. I am not aware of a control measure. There may be some information on the web that may be helpful.
Regards
STeve
