PITTSFIELD -- Berkshire Theatre Group’s two Stockbridge playhouses -- the 400-seat Fitzpatrick Main Stage and the 122-seat Unicorn Theatre -- turn 86 this summer and while 86 may not be a landmark, it is cause for celebration nonetheless, says BTG CEO and artistic director Kate Maguire.

"It’s a completely theatrical season," Maguire said in an interview at her office at BTG’s Colonial Theatre in downtown Pittsfield. "It’s a season in which our actors and designers and directors will have a lot of fun in different spaces."

The Stockbridge campus -- formerly known as Berkshire Theatre Festival -- begins June 24 on the Fitzpatrick Main Stage with Charles Ludlam’s "The Mystery of Irma Vep" (press opening June 28).

Directed by Aaron Mark and featuring Bill Bowers and Tom Hewitt, who between them play eight male and female characters, "Irma Vep" runs through July 19. It will be followed in turn by "Cedars," Erik Tarloff’s exploration of an estranged father-son relationship, directed by Keira Naughton and starring her Tony Award-winning father, James Naughton, July 23-Aug. 9 (press opening July 26); and Michael V. Gazzo’s rarely revived 1955 drama, "A Hatful of Rain," about a returning heroin-addicted Korean War veteran’s struggle to make a life for himself and his pregnant wife, Aug. 13-30 (press opening Aug. 16).

Up the path from the Main Stage, the intimate Unicorn Theatre opens July 9 with Michael Frayn’s "Benefactors" featuring David Adkins, Corinna May, Walton Wilson and Barbara Sims in a play about the hopes, dreams, sacrifices and love among and between two couples living in London in the 1960s. Eric Hill directs. The production is scheduled to run through July 26. Press opening is July 12.

Following "Benefactors" is Noel Coward’s "Design for Living" about an amoral, freewheeling threesome in London in the 1930s. Tom Story directs Yale Drama School graduates Ariana Venturi, Chris Geary and Tom Pecinka, who all appeared in "The Cat and the Canary" last summer in the Unicorn. Performances begin July 30. The show runs through Aug. 16. Press opening is Aug. 2.

Also scheduled for the Unicorn are "Poe," a new play written and directed by Hill starring Adkins as the moody writer and poet, Oct. 2 through 26 (press opening Oct 4); and "A Lover’s Tale: Scenes From Giuseppi Verdi, Charles Ludlam and Alexandre Dumas," treatments of "The Lady of the Camelias," Aug. 23-30.

BTG’s big musical this summer is Stephen Sondheim’s "A Little Night Music," starring Maureen O’Flynn as a Swedish leading lady of the stage who, as fate would have it, is given a chance to rekindle a smoldering relationship with an old flame.

Ethan Heard, who directed last summer’s "The Cat and the Canary," is directing. Performances begin June 30 and continue through July 19 at the Colonial Theatre. Press opening is July 5.

"It feels to me that Stephen Sondheim had this theater (the Colonial) in mind when he wrote this show," Maguire said. "It’s perfect."

The Colonial also will host BTG’s ninth annual children’s theater production. This year it’s "Seussical," a musical by Lynn Ahrens and Stephen Flaherty based on material by Dr. Seuss, Aug. 7-17; and the Ellenoff Musical Theatre Series, a Monday afternoon series of singthroughs of classical American musicals performed by members of the BTG Acting Apprentice Company. Performances are scheduled for 2 p.m. July 7 and 14 and Aug. 11 and 18.

It’s a season, Maguire says, that honors the new and the old in American theater.

The new is Tarloff’s "Cedars" which will have its world premiere on the Fitzpatrick Main Stage.

Tarloff has written for the TV sitcoms "All in the Family," "MASH," "The Jeffersons" and "The Bob Newhart Show."

"He is very funny, but with meaning," Maguire said.

"We are one of the oldest theaters in the country. We have an obligation to support new work."

Maguire says it is just as important to honor older, less frequently revived American plays. Rarely performed works by Eugene O’Neill, Clifford Odets, Tennessee Williams, David Mamet, among others, have found their way onto the Main Stage. This summer, it is "A Hatful of Rain," directed by Greg Naughton.

"Greg has been talking to me about doing this play for some time," Maguire said. "It couldn’t be more timely -- a returning war veteran with PTSD and a heroin addiction trying to adjust to life back in the United States.

"It talks about our war veterans, how we treat them, their struggles with family, how they adjust to life at home, addiction, psychological pressure, the American dream; that asks what the American dream is.

"I think it’s a beautiful and heartbreaking play that talks about who we are as Americans."

Maguire says she particularly appreciates the season’s "family feel": The Naughtons -- father, son and daughter; two real-life couples, David Adkins and Corinna May, and Walton Wilson and Barbara Sims, performing together; a broader family of BTF artists -- Bill Bower, Tom Story, Tom Hewitt, and Maguire’s husband, Eric Hill.

"There’s a lot of relationships here," Maguire said. "It feels comfortable.

"I am grateful when artists say they want to come to us so they can work and be honored in the workplace.

"This summer is a great celebration of our workplace -- the theater."