There is a morning in late February when the plow lights come up a Dracut side street before anyone has thought about coffee — snow pushed back off the driveways, walks shoveled down to the slab, sand laid on the pitch of a hill so the day can simply begin. Griffin Brook Landscaping works that hour and the warm ones too: mowing for homes and businesses across the Merrimack Valley, setting mulch, seeding and sodding thin ground back to green, trimming shrubs and trees, keeping irrigation lines honest through the dry stretch of August. When the light turns gold over the old farm fields, the crews build — landscape design and construction, walls and walks and patios set stone by stone in this fieldstone country — then sweep the yards clean of leaves and square them away for the cold. Their range runs from Dracut through Lowell, Methuen, Chelmsford and Andover, and over the state line into Pelham and Salem, New Hampshire. It is work you can stand back and look at: an edge that holds its line, a patio sitting level under the first frost, a drive already clear while the storm is still coming down.