How to clean muddy oak gall mess
A large branch of an oak overhangs our asphalt driveway. This year, for the first time in more than 30 years in our house, the branch is shedding galls, which distintegrate into a sticky brown mud when it rains. I gather this is because of the gluey lignin in the galls. What is the best way to clean up the stuff without harming plants on both sides of the driveway? A stiff bristle brush barely touches it when it's dry. If I power-wash the area, what cleaning solution should I use, and how can I avoid having the residue collect on the driveway, dry, and recreate the problem all over again? High-concentration vinegar and baking soda both have been suggested. Thanks so much for whatever help you can offer!
Do not use vinegar. You run a high risk of damaging adjacent plants.
We recommend that you wet the area and let it set for a while to soften up, then power wash with water.
Of course, blow or sweep off galls before they get wet when possible.