March in the Gila Valley comes in on wind — dust lifting off the fields, cottonwoods along the river shaking out their first leaves, mesquite holding back until it is good and sure. Arid Plant Designs looks after Pima yards through that in-between stretch, mowing as the grass wakes, edging beds and paths, cutting back the winter's tangle and carrying it off. Out here a lawn is a deliberate patch of green in a wide dry valley, so its shape counts for as much as its color. A firm line where turf stops and gravel begins can make an entire yard look intentional. Spring in this country is short; the work is keeping pace with it.