Mashomack's oaks set the tone for the whole south end of Shelter Island — big, slow, leaning with the prevailing wind — and the yards nearby live in and out of their shade. Long Island Tree Service and Lawn Care. works those half-lit lawns, mowing where the light gets through, trimming back the limbs that crowd a driveway, clearing the branch litter after a nor'easter has had its say. Shade grass is patient work; it asks for a higher cut and a lighter touch, and it repays anyone willing to learn one particular yard. Spring cleanups here mean pulling a winter's worth of oak leaf out of the beds before anything green can start. When the last barrow goes to the truck and the lawn opens up beneath the trees, the property looks like it has finally exhaled.