Twelfth Night, Donmar Warehouse, London<br></br>Gertrude, Riverside Studios, London<br></br>A Passage to Indiam Playhouse, Oxford

Sam Mendes bids a sugary farewell

Sam Mendes is in a valedictory humour. For his finale as the Donmar's artistic director, he's staging Twelfth Night in rep with Uncle Vanya, Chekhov's autumnal "farewell to love". Twelfth Night is the tail end of Christmas when one may indeed feel sad because the party's over – or maybe just because the fun has worn thin. Shakespeare comedy, though it concludes with marriages, certainly has sombre, wintry aspects which Mendes strongly brings to the fore.

The Illyria where Emily Watson's shipwrecked Viola is cast ashore – lamenting her lost sibling, Sebastian – is a sunken vault of dark wood, lit like a shrine by a hundred flickering candles (set by Anthony Ward). You see how love could be a morbid obsession as Viola – crossdressing in her twin's image, under the pseudonym Cesario – becomes pageboy to Orsino (Mark Strong) who idolises Olivia (Helen McCrory) with no hope of winning her heart. McCrory is only seen in his chambers standing frozen in a huge picture frame and dressed in vampish black. Meanwhile, over at her manor, we find Olivia mourning her brother who appears as a ghostly portrait too (embodied by Gyuri Sárossy, who'll double as Sebastian, Olivia's eventual husband). Also on the dark side, there's the "sport" that Sir Toby and his cronies pursue, incarcerating Olivia's smitten steward, Malvolio. Twelfth Night quite specifically shows us how jokes can sour. Anthony O'Donnell is a memorably vindictive and weary Feste. And Simon Russell Beale's Malvolio – after strutting round like a hilariously puffed-up pigeon – becomes tragically terrorised, crumpled in a straight jacket and blindfold. His final vow, "I'll be revenged on the whole pack of you", also conveys ferocious class anger – in contrast to Beale's silent, devastated grief in Uncle Vanya where his adoration for McCrory's Yelena is correspondingly unrequited.

Amongst the rest of Olivia's household, Mendes deftly creates a sense of becalmed life, with muted conversations between domestics and late-night drunks collapsed on sofas. However, one feels deprived of the spirit of youth, of green may mornings and midsummer madness – all of which are alluded to in this season-spanning play. The comedy is generally too shrivelled. David Bradley's Aguecheek is a tedious dolt, and Mendes sets the box tree scene in Malvolio's bedroom with Toby and co eavesdropping (with no farcical ducking and diving) behind a screen that's merely printed with grey etchings of topiary.

That said, explosively funny moments include a wild belch from Paul Jesson's Toby that nearly takes McCrory's head off. She's got a naughty sensuality bubbling up and Watson has go-getting determination. On the side of hope and rebirth, the picture frame is an ingenious device for it doubles as a threshold though which characters step into alternative realms to encounter their dreams. A charmed atmosphere is frequently created by watery, drifting piano music (composed by George Stiles).

In many respects Twelfth Night is, typically of Mendes, a solidly good production. But it's not sensitive to all this play's sexual nuances. Watson is never unsettlingly boyish. Orsino's gay side is roughly sketched in while Olivia's wooing of Cesario becomes desperately crass – suddenly stripping to reveal a see-through dress and fishnets. Mendes's bold, downbeat reading of the play isn't fully followed through either, glossing over delicate exchanges to create a problem-free, sugary denouement for Viola, Olivia and their realigned partners. Hollywood calls.

Hamlet's mother (played by Victoria Wicks) spends most of her time parading around Elsinore in a gauze negligee and no underwear in Gertrude, Howard Barker's latest self-directed play for his dedicated troupe, the Wrestling School. Barker's programme note questionably claims that "Shakespeare's moral sense and his role in a Christian/Reformation society compelled him to routinely punish transgression" and that his own reconceived erotic Gertrude is "passionate, defiant and more authentically tragic than the adolescent prince himself." I can't help feeling that Wicks's Gertrude might just be a pawn in this playwright's voyeuristic fantasies (and she hardly goes unpunished).

Sometimes the dialogue sounds like a hackneyed porn mag dressed up with poetry. Consider, for instance, the over-excited queen declaring, "I'm flooded to my knees", after Sean O'Callaghan's Claudius kills her hubby with a hypodermic then tells her to bend over.

I suppose Barker is unique in his mix of visceral frankness and often ornate rhetoric. His actors are well-drilled, suggesting intense desires and insecurities behind their cruel looks. Tom Burke is a young actor to watch. He plays Hamlet as a sometimes laughable, screwed-up brat with an Oedipal doppelgänger in Justin Avoth's Albert (who's part-Horatio, part-Fortinbras and Gertrude's third lover). The production looks stylish in a stark way, with black and white sliding walls plus clinical/kinky designer gowns.

The problem is Barker's abstracted world, abstruse oratory and seemingly endless line-up of deaths left me feeling wholly uninvolved. O'Callaghan's Claudius is obsessed with hearing some kind of orgasmic, primal cry issuing from Gertrude. One's tempted to see if he'd recognise a yowl of boredom from across the footlights.

In EM Forster's 1920s colonial novel, A Passage to India, sexual transgressions are entangled with interracial relations. Clearly brought out in Martin Sherman's new adaptation for Shared Experience, the tragic irony is that the would-be liberal ex-pat, Adela (pallid, eager Penny Layden), shuns her fiancé's racist imperialist chums only to end up feverishly accusing the local black doctor, Aziz, of sexually assaulting her in some caves.

Other Shared Experience productions have been more thrilling and touching. Some of the novel's rich texture is pared away, Nancy Meckler's 11-strong ensemble fail to bring certain crowd scenes to life on a wide, bare stage, and the expressionistic physical work can seem under-developed.

But the central performances are strong, including Susan Engel's steely old Mrs Moore and Ian Gelder's distressed Fielding – both caught in the cultural crossfire. Moreover, the key scene in the caves potently explores Adela's repressed fears and desires. She pants and stumbles up against rocks that are, symbolically, curled-up turbaned males who catch at her skirts.

Meanwhile, Aziz's conflicting impulses of ingrained racial bitterness and friendliness are sharply captured by Paul Bazely. And the wider tensions Forster saw simmering between Christians, Muslims and Hindus are – lamentably – as relevant as ever. Politically thought-provoking.

k.bassett@independent.co.uk

'Twelfth Night': Donmar Warehouse, London WC2 (020 7369 1732), to 30 November; 'Gertrude': Riverside Studios, London W6 (020 8237 1111), to Saturday; 'A Passage to India': Yvonne Arnaud, Guildford (01483 440000), to Saturday