Urban lot, so space is small. I am wanting to plant a tree in my front yard which consists of a rough 10x10 grass area with a 4' stone retaining wall on three sides (sidewalk, driveway, stairs from sidewalk). Yard is raised 4-5' above the sidewalk. Basement wall is 20' away on the 4th side. Wanting something that grows quick and needing something that can be encouraged to have a tap root since there is very little lateral support. It is a fairly dry location. I was considering a thornless/seedless honeylocust as I have heard that if you cut the top/bottom off of a barrel, bury it, and plant the tree in it that it will greatly contain the ground suckers. But I would definately prefer any other tree if possible.