South of Briarwood the office parks along State Street go quiet after six, and that is when the grounds work gets its clear run of the place. NetZero Property Services covers both halves of the calendar there and in the neighborhoods around it: mowing, trimming and edging with seasonal cleanups when the season turns, then plowing, shoveling and salting once the lots start glazing over in the dark. Ann Arbor winters come in waves rather than one long freeze — thaw, refreeze, a skin of ice on the asphalt by five in the morning — so the salt work matters as much as the blade. There is a real pride in a lot that is already open and dry when the first car pulls in. Nobody sees the hour it took, and that is rather the point.