I dunno, Rick. I have let things get more root-bound than I'm happy with before setting them out, and then when I clean up the containers in the fall, ripping out the dead stuff, that whole block comes out intact, as though the roots really never went any farther. I think a lot depends on the type of plant as to whether or not letting them get root bound is good or not. Maybe ok for some perennials and not so good for annuals?