The summer concert season at the Bowdoin International Music Festival remains a lot of melted snow and months away. But founding artistic director Lewis Kaplan has big plans for the 50th anniversary season, which also happens to be his last.

Kaplan steps away from his duties at the conclusion of the festival, which runs June 28 to Aug. 9.

Among other things, Kaplan plans to present Beethoven’s full cycle of 16 string quartets, which will be performed by four quartets on successive Monday evenings. The quartets are the Ying, the Shanghai, Pacifica and Brentano.

Both the Brentano and Pacifica have Bowdoin festival alumni among their members.

The Beethoven cycle is something Kaplan has wanted to do for many years. This being his last, now is the time.

In addition, Kaplan has invited back many of the festival’s most popular performers from the past, including Ray Chen and Sarah Chang, and the festival will premiere five news works commissioned for the 50th season.

David Ying, cellist in the Ying Quartet and co-artistic director-to-be, along with his younger brother Phillip, said the six-week festival is designed with a 50th celebration in mind.

“Lewis is thinking of everything. I think he wants to roll everything he has ever wanted to do into one year. Any stone that he left unturned, he is trying to turn over this year,” Ying said.