GREETING SEASONS: Things are relatively quiet right now on the hometown theater front. Which is not to say we've come to a standstill -- the old "summer doldrums" cliche' is patently untrue when it comes to theater.

True, plenty of actors and directors are vacationing or working out of town in summer stock. But several shows -- "Sherlock Holmes," "The Immigrant," Woolly Mammoth's two-play rep, "A Sondheim Evening" and the eternal "Cats," among others -- are running along successfully into the summer, Source Theater's festival is generating lots of alternative energy and the folks behind the scenes are busily planning what we'll see in the fall. Here's a glimpse of what we can look forward to when everyone gets back:

At Arena Stage, the season starts with the Yale Repertory Theater production of August Wilson's "Joe Turner's Come and Gone," a drama about the residents of a Pittsburgh boarding house. It will be directed by Lloyd Richards, who directed Wilson's Tony- and Pulitzer-winning "Fences." ("Joe Turner" opens October 2 in the Kreeger). By the way, Richards will also direct Wilson's newest play "The Piano Lesson," which is due to open on Broadway in April.

Robert Penn Warren's "All the King's Men" is up next, in an adaptation by Adrian Hall of the Trinity Repertory Company, with music by Randy Newman. Arena associate producing director Douglas C. Wager will direct (opens October 16 in the Arena). Then there's Moss Hart's "Light Up the Sky," a comedy about a bunch of theater types awaiting the reviews of their latest production. James C. Nicola directs (opens December 11 in the Arena). "Enrico IV" by Luigi Pirandello, will be directed by Arena's producing director Zelda Fichandler (opens January 1 in the Kreeger). Lorraine Hansberry's "Les Blancs" will be directed by Harold Scott, who directed the recent revival of "A Raisin in the Sun" at the Kennedy Center ("Les Blancs" opens February 5 in the Arena). The anarchic spirit of the Marx Brothers rises again in "The Cocoanuts," with book by George S. Kaufman and music by Irving Berlin. It will be directed by Doug Wager, who staged Arena's memorable "Animal Crackers" in 1982 (opens April 15 in the Kreeger).

And Arena's season finishes with Anton Chekhov's "The Cherry Orchard," marked by the return of noted Romanian director Lucian Pintilie, who made an indelible impression on D.C. with his productions of "Tartuffe" and "The Wild Duck" (opens April 29 in the Arena).

The Shakespeare Theater at the Folger just announced its four-play season, which starts with "The Witch of Edmonton," a recently rediscovered tragedy written by Jacobeans John Ford, Thomas Dekker and William Rowley. "Witch" will be directed by Barry Kyle, associate director of the Royal Shakespeare Company, making his American debut with the Folger production (begins previews September 29). Artistic director Michael Kahn will stage William Shakespeare's "All's Well That Ends Well" (December 8) and "Macbeth" (February 16). And Shakespeare's "Coriolanus," a first for the Folger, will be directed by Michael Langham, director of Juilliard's drama division (April 26).

Over in Georgetown, Horizons Theater assembled last week for its annual retreat and emerged with plans for a three-play season. Artistic director Leslie Jacobson says the troupe cut back on the number of shows because of constraints of its church space schedule (and the absence of air-conditioning), and to allow for longer runs. Entering its 11th year, the "Theater From a Woman's Perspective" will also present its first play written by a male playwright. The season: "A . . . My Name Is Alice," a satirical musical revue conceived by Joan Micklin Silver and Julianne Boyd and written by "a cast of thousands"; "Scheherezade" by Marisha Chamberlain, which is about the aftermath of a rape but is not a revenge play; and "Eleemosynary" by Lee Blessing, the man in question. Horizons' season will also include three panel discussions that will be related to the plays.

First up at other Washington theaters: Studio starts off with "North Shore Fish" by Israel Horovitz (father of Beastie Boy Ad-Rock); Source will begin with "How I Got That Story" in September; Round House opens with Keith Reddin's "Rum and Coke." Castle Arts will reopen in September with a reprise of its Helen Hayes Award-winning musical "Quilters."

And Georgetown's Trinity Players will finish its 12th season with an original musical by two Washington artists. "Monster of Muldoon," a new musical with book and lyrics by Brian Ruberry and music by Jon Carroll (ex- of Starland Vocal Band), is about a 12-year-old boy who brings his mom's fiance' back to life.

Bulletin Board: Local girl makes good -- "The My House Play" by Arlington playwright Wendy MacLeod will be presented Friday and Saturday at the 1987 National Playwrights Conference at the O'Neill Theater Center in Waterford, Connecticut. The Center selected 14 playwrights from more than 1,500 applicants to present their work at the conference (August Wilson's "Fences" was first staged here). MacLeod recently completed graduate studies in playwriting at Yale; her play is about a family whose house and security are threatened when Interstate 66 is scheduled to go through their patio . . . The actors at the Washington Stage Guild are keeping busy with free readings from the works of great American novelists at the National Portrait Gallery. This Friday at 7:30, Flo Gibson and Mary R. Woods will read works by Edith Wharton and passages from Henry James' "The Turn of the Screw"; Monday through Friday at noon, Laura Giannarelli will read from Bret Harte. Call 357-2920 for reservations and info on future readings . . . Summer camp: If you happen to be in New York this summer, and you find yourself miserable because you can't get into "Les Mise'rables," you might try "Psycho Beach Party," which opens Monday at the Players Theater. The play, which used to be called "Gidget Goes Psychotic" (alas, "Gidget" is a copyrighted name), is another camp romp by Charles Busch, who plays the title role. "Psycho" alternates with his three-year-running "Vampire Lesbians of Sodom."