When irrigation water comes back into the Grand Valley ditches each spring, the whole town seems to exhale green. Liqui Green Turf & Tree Care works that turn — mowing, feeding and aerating lawns from the first flush of April growth to the last mild week of October. Then the valley inversion settles in, gray and still, and the work becomes plowing and shoveling, salting a walk so the mail carrier doesn't slide. Between the Government Highline Canal and the river, a Grand Junction lawn is a human invention, and it repays attention. Both halves of the year get the same steady hands.