Joint venture: Pineapple Express

IF YOU WERE TRYING TO SELECT the right person to refurbish that perpetually half-baked genre, the Hollywood stoner comedy, you might very well ask Judd Apatow, the current king of schlubby, non-alpha-male humour, to serve as producer. And you could easily imagine Seth Rogen, leading man of Knocked Up, co-writer of Superbad and someone whose CV suggests at least a passing familiarity with the munchies, as co-writer and star. But David Gordon Green in the director's chair?

In the parlance of the main characters of his new movie, Pineapple Express: Whoa? What? Seriously?

For ten years, Green, 33, has been making small independent movies praised for their meditative delicacy, naturalistic performances, exquisite visual composition. They have taken home some very nice awards. His directorial debut, the self-financed George Washington, a gentle portrait of a group of rural American children, was named the best first film of 2000 by the New York Film Critics Circle. But even the most successful of his four movies, 2003's All the Real Girls, made very little at the box office. And winning something called the Sundance Special Jury Prize for Emotional Truth isn't something to pin to your lapel when persuading Sony executives that you're the man to make their next comedy.

Green insists it's a more natural fit than fans of his earlier work might assume. Growing up outside Dallas in the late 1980s he indulged his appetite for the goofiest low-end action comedies.

"I was into some trash," he says, unrepentantly. "It wasn't even prestigious trash, like the taste that Tarantino has. I mean trash."

The Billy Crystal-Gregory Hines action comedy Running Scared, Kurt Russell and Sylvester Stallone's Tango & Cash, Rowdy Roddy Piper in They Live, Missing in Action, Death Wish 3 – the late 1980s were clearly formative for him.

Which isn't to say he didn't aim higher with Pineapple Express. The story revolves around a process server, Dale Denton (Seth Rogen), his hapless, sweet-natured pot dealer, Saul Silver (James Franco, cast against type in the role Rogen originally intended to play); and the local drug lord (Gary Cole), who starts hunting the two when Dale witnesses a murder.

"I think my spin was to try to make it not a cartoon," says Green. "I thought, let's go far-out and absurd places, but let's try to play everything as if it's for real and try to root it in human behaviour. When these guys get in fights, they're not used to fighting, so it hurts, and they're really sore the next day. To me, it's funnier that way."

Pot comedies seem to be flourishing lately. Those who will always view the Cheech and Chong ouevre (particularly 1978's Up in Smoke) as archetypal can find their natural heirs in the two Harold & Kumar comedies (a third is in the works). To inhale something a little different, you can sample a 1990s period piece (The Wackness); Gregg Araki's little-seen Smiley Face; or the pitch-black comedy of TV series Weeds.

Green's film is a hybrid: it merges all of the above with an attention to the fumbling, heartfelt friendships between straight guys that were a staple of Knocked Up and Superbad, both productions of the Apatow comedy factory.

The matchmaker on Pineapple Express was the film's third lead, Danny McBride, Green's occasional writing partner and a friend from their days at the North Carolina School of the Arts. Apatow was a fan of McBride's work in The Foot Fist Way (a film much admired in comedy circles) and invited him to the set of Knocked Up.

"I'd never met Seth and Judd before," McBride says, "and it struck me that the way Judd worked was very similar to the kind of work David did, where everybody knows the rules. The script can go out the window as long as you don't break character."

After his most recent drama, last year's Snow Angels, Green wanted a change. "I was thinking that in order to prove to the industry that I'm the right guy to make somebody giggle, I might have to make a kind of down-and-dirty, lo-fi comedy," he says. "Then this popped up." He was wary of the studio route. "We've all heard horror stories. I have friends who have made the leap not so comfortably."

Green has already had his share of frustrations over bigger projects. He is one of many film-makers to have passed through a long-delayed adaptation of John Kennedy Toole's novel A Confederacy of Dunces; and a planned adaptation of John Grisham's non-fiction The Innocent Man went into limbo in May when Warner Brothers decided to shut down its indie divisions.

A brush with hot commodity status before the 2004 release of his drama Undertow, a brutal Southern Gothic melodrama inspired in part by Charles Laughton's Night of the Hunter, still stings a little. "Everyone wanted to see a print, said it was going to be huge. I was getting all kinds of offers to work with amazing people," Green says. "Then the movie opened. It made, I think, about $170,000, and the jobs dried up in a minute. That was my lesson in fair-weather studio friends."

But on Pineapple Express Green discovered the advantage of working with a producer whose recent track record of hits guaranteed that there would be little or no studio meddling. "People think 'independent' means no interference," he says. "Not true. Unless you're paying for everything yourself, you're always subject to who's writing the cheques. And on this movie I had more creative freedom than I've had since George Washington."

"The basic idea of hiring inspired, independent-minded film-makers is a much better way to go than to hire shooters who will do anything you tell them to," says Apatow. "David's movie retains our style and tone while merging with his. He makes the characters and their relationships come to life and not feel like an afterthought."

Green threw himself into the action sequences, including a hilariously inept three-man house-wrecking brawl that took four days to film, and he says he encouraged Rogen, Franco and McBride (not that they needed it) "to try new things, ridiculous line readings, to spur the odd-couple dynamics".

Many of the biggest laughs emerged from improvisation. Several were added after initial test screenings showed, unusually, that the audience liked it longer. "Things that I thought would be too weird, people were ready to rock with," says Green, an enthusiastic participant in the testing process. "I really valued it. To me it's important that this movie be engineered not only to my self-indulgent sensibility, but to a mass audience."

On a recent visit to New York, Green, who lives in New Orleans, found himself staring up at a billboard of his movie. The billboard alone has probably been seen by more people than his body of work to date. "I cried," he says, grinning. "You know, a sweet tear. People have said to me, 'Oh, so you made this one for them, and now you can make a movie for you.' No, I didn't. This wasn't a hack job. In a strange way it was a passion project."

Whatever comes next for Green, it is not likely to be an immediate return to painfully intimate dramas. He recently finished collaborating on the script for a remake of 1977 horror movie Suspiria. He's also working on an Arctic submarine adventure and a pilot for an animated series. He and McBride are planning a "medieval comedy with dragons". And – lest anyone doubt the depth of his taste for the lowest of 1980s subgenres – he's working on a remake of the Kenny Rogers race car movie Six Pack.

"I'm trying to channel as diverse a career as possible," he says, citing Richard Linklater, Gus Van Sant and Steven Soderbergh as models. "It's good for me to switch gears. I don't like the idea of someone looking at me funny when I say I want to do something. I like the idea of them saying, 'That's interesting.'"

• Pineapple Express is released on 12 September.