Can someone tell me how close a maple tree can or should be planted near our a brick wall. This wall was simply put there for privacy so it is not holding anything etc. We had two maples self sow themselves on our property and I like where they are but wondered if they are too close to the wall. The root system is not a concern as there is a vacant field behind us and will remain that way. But I am concerned about the trunk being too close to the brick. Can you suggest a safe distance from the wall. Thanks so much.