Up in the Highlands the streets stack themselves along the hillside in terraces, and nearly every lawn is a small slope with a retaining wall holding it in place. Kane Brothers Landscaping mows that kind of ground for a living — up and across, tight to the wall caps, hand-trimmed where a mower cannot sit level. Front borders are edged and topped with mulch, shrubs kept back off the steps, and leaves carried away in fall rather than pushed to the curb. The season here stretches out, greening early on the sheltered blocks and holding into November on the sunny faces. A hill lawn cut evenly looks like it was easy, which is the entire point.