I have a home in Pennsylvania with a wall built in the 1940s from large stone as seen below. The level of the lawn is ~3 feet above that of the top of the wall. I worry about this in terms of drainage, as I would prefer that less of the water from that area drain to the wall. The wall does have some cracks in the mortar, but it is otherwise sturdy.
Does is make sense to try and build more retaining wall above the existing wall? - settle a debate between me and my wife.
Is it appropriate to simply grade off some of the slope and plant ground cover, since it is difficult to mow grass on that slope?
What is a good way to clean that stone?