South of downtown, a jet out of Hobby drifts low over a block of brick ranch houses, each with a pecan tree, a chain-link gate and a patch of grass that never quite quits growing. Down along Sims Bayou the herons stand stock-still in the shallows, and the afternoons smell of cut grass and someone's barbecue. In Houston the mower comes out in March and again in November, and in plenty of years it barely rests through January, so lawn care here is less a season than a steady heartbeat. Yard Pro keeps that beat for Houston yards with regular mowing, trimming along the fence line and edging the driveway square. By Sunday supper the pecan's shade spreads over grass that is level and green, and the kids' kickball game has a proper field again.