Posen is built close, bungalows shoulder to shoulder, parkway strips between walk and curb, back yards squared off by chain link. New Look Lawn & Tree Full Service Inc mows those tight south-suburban lots the way they have to be mowed, one careful pass at a time, with the trimmer taking the ground along fences, posts and the alley line. On a village block, one kept yard lifts the four around it, and a crisp curb edge shows from the far end of the street. Summer here means heat coming off the pavement and grass that wants to grow anyway, so the route holds its rhythm week to week. When autumn lets go all at once, the leaves are cleared before they pack down on the walks.