The Martha’s Vineyard Playhouse opens its summer main stage series June 22 with a play about a pair of American writers whose 30-year friendship was as deeply devoted as the most passionate lifelong love affair.

Playwright Sarah Ruhl mined the collected correspondence — some 800 pages — of Elizabeth Bishop and Robert Lowell to create Dear Elizabeth, which runs through July 6.

Bishop and Lowell were two of the most honored poets of the 20th century, but the play is about much more than their writing, said director Joann Green Breuer.

“You don’t have to know anything about either poet or have read any of their works,” she said.

“This play is really about the relationship between two people who struggle in life and yet are able to express themselves in ways that many of us wish we could and don’t — and to express the kind of things that are rarely, if ever, expressed.”

Lowell’s longing for Bishop might have resulted in marriage if she had been attracted to men, instead of women — or if he had simply proposed.

Cast and director earlier this week preparing the show. — Jeanna Shepard

“Asking you is the might have been for me, the one towering change, the other life that might have been had,” he confessed in one of the letters that inspired Ms. Ruhl to write Dear Elizabeth. But the bond between the two was profound, lasting through bouts of mental illness and alcoholism on both their parts and two of Lowell’s three marriages, until the day of his death at 60 in 1977.

“They basically really enjoy each other and I think we will enjoy them as well,” Ms. Green Breuer said.

Dear Elizabeth premiered at the Yale Repertory Theatre in New Haven in 2012 and has also been produced in Berkeley, Calif. and New York city.

But, Ms. Green Breuer said, “It’s never been done this way. Never.”

For Dear Elizabeth at the playhouse, Ms. Green Breuer has gone beyond simply directing the show, also creating the production design and taking part in its installation. “I had the ruler in my hand,” she said.

“For me the design is another character,” continued Ms. Green Breuer, who taught drama at Harvard before retirement. “That was very important to me, to create a world that was both a world of their reality and of their incredible imaginations.”

Jeannie Affelder, whom Ms. Green Breuer directed last summer in a playhouse reading, didn’t need to audition to play Elizabeth Bishop — the director picked her for the part.

Director Joann Green Breuer also created the production design. — Ray Ewing

“Sometimes, someone just is waiting for a role,” Ms. Green Breuer said.

Robert Lowell is played by Raymond Fox, a veteran stage actor who auditioned by video.

“When it feels right, it feels right, and this felt absolutely right,” said Ms. Green Breuer.

“I think the most important thing a director can do is cast correctly and then trust that you’ve cast correctly,” she said. “You have to believe that eventually they will know more about the characters than I ever will, and you have to trust their knowledge.”

Dear Elizabeth runs just under 90 minutes, with no intermission.

The next play in the summer season is Christopher Durang’s Vanya and Sonia and Masha and Spike, opening July 16. The play won the Tony award for best play in 2013.

Directed by Ms. Bruder Munafo, the absurdist comedy mash-up stars Stephan Amenta, Ellie Brelis, Cate Damon, Shelagh Hackett, Mona Hennessy and Brandon Whitehead. It runs through August 3.

The final full production is the musical revue Low Down Dirty Blues, conceived by Randal Myler and Dan Wheetman and directed by Mr. Myler.

Felicia Fields, CE Smith and Chic Street Man play veteran blues musicians who swap stories and songs in an after-hours jam session, with nearly two dozen vintage blues numbers made famous by the likes of Howlin’ Wolf, Muddy Waters and Ma Rainey.

Opening night for Low Down Dirty Blues is August 13.

The playhouse’s Monday Night Specials return starting July 1. These one-night-only readings of new plays begin with Sid & Howard by Mark Kirkeby, who brings together Rhode Island legends H.P. Lovecraft and S.J. Perelman with comic results.

Maggie McDonald Condon’s The Broken Closet, a drama about heroin addiction, follows on July 22, and Deborah Yarchun’s near-futuristic Drive on July 29. London-based writer J.B. Miller brings his new dramatic work Mona/Lina to the playhouse August 19. The reading series concludes August 26 with Edward L. Beck’s Ungodly Pursuits.

Both August readings concern timely and sensitive topics: Mr. Miller’s explores buried childhood memories and Mr. Beck’s is about a priest under suspicion amid the Catholic clergy sex abuse scandal.

The playhouse’s 2019 outdoor Shakespeare production at the Tisbury Amphitheatre is A Winter’s Tale, July 11 to August 11. The family-friendly, comic romance is directed by Brooke Hardman Ditchfield, who directed the captivating musical version of As You Like It at the high school earlier this year.

The amphitheatre also hosts The Fabulists theatre for children every Saturday morning at 10 a.m., beginning July 6.

For tickets and more information, visit mvplayhouse.org.