GARDEN VARIETY: New York’s Museum of Modern Art will host its annual spring benefit on May 21, when it will honor Mayor Michael Bloomberg, along with artists Ellsworth Kelly and Cindy Sherman, WWD has learned. The event, sponsored this year by Cartier, will also serve as a birthday celebration for Kelly, who will turn 90 later in May. Diane von Furstenberg and Barry Diller, Alisa and Dan Doctoroff, Agnes Gund, Jo Carole and Ronald S. Lauder and Jack Shear will serve as cochairs. Following dinner, the band Fun will headline the annual after party in the museum’s sculpture garden.