This seems like it might be the summer of Jeff Koons in New York. His retrospective open at the Whitney on June 27 and timed to that will be the appearance of “Split-Rocker,” his monumental, flowering, toylike sculpture. It is already beginning to take shape at 30 Rockefeller Plaza, on the spot where the Christmas tree is put up every year. Fourteen years ago, his 43-foot-tall “Puppy,” with 70,000 flowering plants, was in the same sop and was one of the most popular artworks ever shown there. “Split Rocker” will weigh 150 tons and be over 37 feet high. It is composed of two halves: one based on a toy pony of one of Mr. Koons’s sons, the other on a toy dinosaur. It’ll be covered with live flowers; petunias, begonias, impatiens, geraniums and marigolds and more. Larry Gagosian, Koons’s New York Dealer, is paying for the installation, and said “Split-Rocker” is “very Duchampian,” adding, “It’s really a ready-made.” “Split-Rocker” will be at Rockefeller Center through Sept. 12.

Koons’s 43-foot-tall “Puppy,” with 70,000 live plants was one of the most popular artworks ever shown in Rock Center