The best-kept secret of Chicago is what happens behind the buildings: a second city of small back lawns, garden plots and garages, all of it reached from the alley. JR Landscaping Services works that side of the block through the growing months, mowing the yard, running the trimmer along the chain link and the garage slab, edging the path from the back porch, and hauling the clippings off instead of leaving a pile by the gate. Tight ground rewards patience more than speed. Come the first warm Saturday the grass is even, the borders are sharp, and the yard is ready for a table and a folding chair. That is the whole idea.