When will the Stratford Festival recapture its former luster?

This southern Ontario manufacturing town shares its name with Shakespeare's hometown in England. And, like that English town, it also has a theater festival , founded in 1953 by Sir Tyrone Guthrie. With a few lapses through the years, it has probably been the finest festival theater company in North America.

After the abrupt departure of Robin Phillips four years ago - during whose tenure the theater was at the peak of its capacities, reputation, and ability to lure audiences and stars alike - a near-fatal crisis developed. The all-Canadian troika appointed to succeed Phillips was fired a scant few months into its term to make room for John Dexter. This was hardly good news in some nationalistic quarters here; the Stratford Festival board, in its clumsy handling of the firing and appointing, opened the storm gates to tidal waves of ugliness that nearly sank the festival altogether.

Although the storm has subsided, the long-term effects and repercussions are still evident. Under John Hirsch, the man who was finally given the top job, the festival has not flourished. The annual budget has skyrocketed, while the number of productions has been drastically cut back. Productions are listless, and stars of the caliber that Phillips and his predecessors were able to lure are simply not coming.

In an interview in the festival issue of Stratford's Beacon Herald, Mr. Hirsch likens his theater to the Metropolitan Opera in its scope and flatly declares it ''a national treasure, providing, ''without a doubt, some of the finest entertainment available on this continent.'' Associate director Michael Langham talks in the same issue about a rebirth of Stratford in the past two years.

This rebirth is, unfortunately, not yet visible on stage. In fact, the four productions I saw this summer have far more to do with expensive summer stock than with festival theatrical enterprise. And all four evinced an alarming lack of intellectual curiosity. Generally, there seems a complacent contentment with merely getting shows on without major mishap - the director as traffic cop. In Gilbert and Sullivan's ''Iolanthe,'' director Brian Macdonald used the show as a desperate, mean-spirited lampoon of old-fashioned theatrical values.

Nowhere was there a sense that any one of these offerings - which also included ''A Midsummer-Night's Dream,'' ''Waiting for Godot,'' ''Love's Labour's Lost'' - had anything to say about the human scene, about political issues, about the very fiber of humanity and man's relationship to himself. Mr. Langham seemed content, in ''Love's Labour's,'' to plot circular paths on the stage and let the actors fend for themselves, rather than to make the issues in the play clear, or to make the characters come truly to life. Also, the miscasting, top to bottom, was distressing to see on a stage where some of the great names in the theater of the past quarter-century have trod.

Mr. Hirsch's ''Dream'' fared no better, despite the presence of Patricia Connolly, an often radiant actress, as Titania. In an attempt to recall 19 th-century theatrical values, the stage was floored in a startlingly unattractive Desmond Heeley creation that was meant to represent a forest scene. It was there all evening long, thus removing from view the crucial Shakespearean contrast between stark city and verdant, peaceful forest. The younger actors, who all seemed overparted, tended to hurl their lines toward the rear walls of the theater. There was a sense of bitter anger in the Oberon (Nicholas Pennell) and Titania (Miss Connally) that was never justified in the production. Brian Bedford as Bottom gave a performance too full of gestures, halts, and grimaces.

The same mannerisms were fully in view in his performance as Vladimir in ''Waiting for Godot.'' This play is now a classic, and one wonders why it was necessary to give it so dated, slavishly literal a production (by Leon Rubin of the Royal Shakespeare), which seldom indicated the director had thought about the work. Edward Atienza gave a quaint, clownish touch to Estragon that played well off Mr. Bedford, but never really went anywhere interpretively. The Pozzo (Andreas Katsulas) was more concerned with his voice than with the role. Ultimately, it was only Paul Zimet's Lucky that really made a small Beckettian statement.

G&S evenings

Ever since John Hirsch took over, the smaller but delightful Avon Theatre has become a Gilbert and Sullivan house, where serious, provocative plays and productions were once showcased. These G&S evenings sell out (where the main stage might be only half full), and what the people get is mindless entertainment that is not even as good as the standard the D'Oyly Carte used to offer. This ''Iolanthe'' was poorly sung, wildly overproduced, and derisive in tone. Maureen Forrester, as the Fairy Queen, decked out like Queen Victoria, was asked to fly on trapezes, boom out chest tones like a foghorn, and generally carry on with extravagance. But at least she knows how to keep things (just barely) within the bounds of good taste. And, if the pattern of past seasons is set, this ''Iolanthe,'' which closes Sunday, may be seen in Canada this winter and will surely be back at the Avon next summer.

On the docket for the rest of the season are productions of ''The Merchant of Venice,'' ''Henry IV, Part I,'' ''A Streetcar Named Desire,'' ''Separate Tables, '' revivals of ''The Mikado'' and ''The Gondoliers,'' and ''Tartuffe.''

Variety reported a few months back that a search committee had been appointed to find a successor to Mr. Hirsch, whose contract is, apparently, not being renewed. Whoever that successor may be, it must be someone who can restore luster to the festival, for when that luster returns, so will the sort of public that seeks out the best and appreciates it.