Among the city’s best-known rites of spring are hay fever, cursing George Steinbrenner, and, of course, picnics. You don’t need help with the first two, but picking the right picnic spot out of the thousands of acres New York has to offer can be tricky. Parks Commissioner Henry Stern has a few ideas: “I think I would have to recommend some spots near the water. I like the shoreline of Turtle Pond in Central Park. There’s also a nice enclave on East 37th Street with some breezes from the East River.” Outside Manhattan, he suggests checking out the appropriately named Picnic House in Brooklyn’s Prospect Park, which overlooks the Long Meadow, or Herman MacNeil Park in Queens on the shore of Long Island Sound.