In the garden, the start of the growing season means the return of dirt under our fingernails, the scent of freshly spread mulch and the first blooming roses. In my neighborhood, and perhaps yours, it also means an audible onslaught of lawnmowers, leaf blowers and other tools of the landscaper’s trade. From 8 a.m. through at least early afternoon — five or six days every week — the hum of power tools and other machines disrupts my peace.