I will plant shrubs and small trees in several beds around our front yard where the lawn is. The lot is not flat at all, and the lowest part is in the center. Since the beds are around the lot; they will be higher than the lawn. I am just concerned that if I till the entire bed and then it rains, all the red clay dirt will run into the center of the lawn. The lawn will then be stained with red clay color. Should I just till only the spots where the shrubs and trees will be planted? I am not sure even if it's worth to have the concern. What should I do then? Thanks