Having been with the team since its inception, in 1962, Mr. Flynn was named head groundskeeper in 1974, a post he held until 2001, overseeing a crew that now has more than 15 members. Rather than retire, though, he rejoined the crew.

Mr. Flynn did more than maintain a fairway-trim field in the middle of Queens; he also welcomed visiting dignitaries and celebrities. After the Beatles played their historic Shea Stadium show in 1965, he drove John, Paul, George and Ringo from center stage to the center-field fence, where an armored car waited to help them escape nearly 56,000 screaming fans.

Forty-three years later he drove Paul McCartney to the stage in a golf cart when Mr. McCartney made a surprise appearance at a Billy Joel show, the last concert held at the stadium. Mr. Flynn was also on hand in 1979 when Pope John Paul II rode onto the field, and he recalled that rainy skies lifted when the pontiff arrived.

Keeping the grounds pristine at the Mets’ three home fields since 1962 was no easy feat.

Shea Stadium was also home to the New York Jets for most of their first two decades, so Mr. Flynn had to deal with the seasonal damage wreaked by professional football players. He weathered a four-team assault on his turf when the Yankees and the National Football League’s Giants joined the Jets and the Mets as Shea Stadium tenants in the mid-1970s. (Giants Stadium in New Jersey was being built, and Yankee Stadium was being renovated.)

The Kentucky blue grass in the outfield had to be kept at a uniform length, the clay around home plate and on the pitcher’s mound had to be mirror-smooth, and the infield dirt, a combination of sand, clay and silt, was more carefully maintained than a Zen garden’s sand.