Joni Mitchell has announced her public retirement, claiming her performance schedule has made it impossible to continue a song writing career and develop her interest in painting.

She conveyed this feeling through her manager, Elliott Roberts, as she left her Los Angeles home for a month-long vacation in Canada. Roberts said his client would spend most of that time with her family in Saskatchewan, performing only once during the month, at what he called "a nuns’ convention near Toronto."

"She hasn't been able to write since trying to become a super star," Roberts said. "Next fall, after she gets some more material together, she may want to do some isolated concerts again, but I doubt it. Performing just isn't what she wants these days."

The "retirement" involved cancellation of two important February dates, in New York's Carnegie Hall and Constitution Hall in Washington, while Roberts said an additional 15 concerts had been refused in the past weeks.

Not counting the performance for the nuns - one of whom was reported to be a close friend of hers - Miss Mitchell will appear in the U.S. only five more times. These concerts will be at Boston Symphony Hall, December 5th; the University of Hartford, December 7th; Springfield College, December 10th; the College of Holy Cross in Worcester, December 12th; and Kleinman's Auditorium in Buffalo, N. Y. December 13th.

Her last scheduled appearance will be in Royal Festival Hall in London, February 7th.