The Deertrees New Repertory Company, a group of Maine-based actors and directors, is in the midst of staging a dozen performances at the historic Harrison theater this summer.

The performing group complements the theater’s traditional offerings of almost nightly musical performances through the summer months. The newly formed troupe, however, represents a departure for the 78-year-old theater, which has traditionally paid commercial groups from the Boston or New York areas to perform.

The new arrangement allows the members of the troupe, composed of primarily young people from the Greater Portland area, to perform throughout the summer. It is also less expensive for the theater, since local performers do not require housing accommodations.

Andrew Harris, the theater’s executive director, said he was excited to pay Maine actors to perform at Deertrees.

“I have a great admiration for the talent that’s in Maine, and frequently there is not enough work for them,” Harris said. “There’s a limited amount of work for the number of good actors in Maine. It’s a way of marrying up the needs of that talent and the needs of the theater. We’re not able to stage theater as it’s been done in the past. It’s just too prohibitive cost-wise.”

The 21-person company is putting on three different shows, each of which will be performed four times. The company will present “The Selfish Shellfish,” a play about “the daily trials of the creatures who inhabit a rock pool,” on July 19, 26, and 31.

“Heroes,” which will be staged July 25, Aug. 2 and 8, is set on a garden terrace at a retired soldiers’ hospital in 1959, where World War I veterans, out of sheer boredom, hatch a plan to escape.

Finally, the “Grand O’Neal,” written by David Butler of Gorham, revolves around a Cleveland couple who, in an attempt to find their ancestral roots, take a vacation in Ireland. It runs on July 26 and Aug. 1, 9 and 15. “The Selfish Shellfish” and “Heroes” have already run once.

“I think they are good summer fare,” Harris said. “They are fun. Nothing too heavy. I’m always critical about ‘Macbeth.’ It’s pretty dark and heavy. If you’re going to do something in the summer, you might as well do ‘Twelfth Night.’

Shannon Wade of Portland designed puppets for “The Selfish Shellfish.”

“It’s my first professional puppet-designing opportunity, and I’m happy to be able to bring all my ideas to the table and feed off of our set designer and our director in what direction we want them to go. To have that creative free rein is really exciting,” Wade said.

Wade said that almost everyone involved in the show is in their 20s.

“This has been a great experience for our cast of relatively young actors to get this professional experience and also to be able to really work and collaborate together in kind of a large-scale venue and one that will be seen by a lot of people,” she said.

The Deertrees New Repertory Company will present “The Selfish Shellfish,” a play about “the daily trials of the creatures who inhabit a rock pool,” on July 19, 26, and 31.