I would first off like to introduce myself and say hello. I found this site while looking for information on lawn care and it looks to be an excellent resource for land and hardscaping. I recently purchased some Ortho Groundclear to use on a slate patio that I have in my backyard. The vegetation killing, year long protection sounded good. However, after reading the label (something I always do now) I noticed that in the disclaimer, it explains that you shouldn't spray Groundclear within twice the diameter of the trunk of any trees as well as the drip zone which is visually shown as the area covered by the canopy. Here's the catch- on either side of my patio are two MASSIVE oak trees. They are amazing and provide the back patio with great shade, aka "drip zone." The LAST thing I want to do is spray this Groundclear, kill the weeds and somehow damage the oaks. Should I use a weaker weed killer (Round up) on this patio instead of the more potent Groundclear because of these trees? I have included a picture of the patio to show the proximity of the oaks to the patio and weeds in question. Thanks for any advice you could provide.