The Megunticook comes down through the middle of Camden and drops into the harbor in plain sight of everybody — a river that reaches salt water in the space of a block. Jackson Landscape Services keeps the ground on both sides of it: lawns mowed and edged all summer, beds cleared in spring, leaves hauled off in the bright cold of late October. When the year turns, the same properties want plowing, shoveling and sand on the walks. Coastal storms can throw rain, then snow, then a hard freeze in one night, so the work reads the weather rather than the calendar. What stays constant is a place that looks tended.