Ann Arbor rarely gets one clean freeze; it gets a dozen, with thaws between them that turn Monday's slush into Wednesday's sheet of ice. Premium Lawn Solutions takes the winter side of a property along Packard and the streets that fall away from it — plowing drives, clearing walks and steps, and treating with salt where meltwater runs and then stops short. The gray stretch from January into February is long in this town, and the difference between a manageable house and a treacherous one is whoever stays ahead of it. Done right, this work is nearly invisible: no ruts, no glaze at the apron, no guessing where the drive meets the street. That is what is on offer here, storm after storm.