Discovery is hoping to parlay the "green" living movement into greenbacks with Planet Green, a new cable network due June 4.

And the channel is using celebrities — including rapper Ludacris, rocker Tommy Lee and actor Adrian Grenier — to soft-pedal its mission and win over casual "armchair environmentalists."

The target audience: college students, baby boomers and new parents who have demonstrated an interest in improving the planet by changing their ways of living.

"It used to be that green was granola and left," says Discovery Networks CEO David Zaslav. But with interest in environmentalism broadening beyond the hard-core planet-in-peril preachers, Discovery is eyeing a mainstream audience for its brand of advocacy.

"We're not going to be "The ice is melting,'" he says; the audience already gets that message. "We want to engage people in a fun way and in the spirit of what we can all do together."

Though other cable channels offer programming blocks, this is the first fully "green" channel. And in a rare move for a start-up, Planet Green plans a nearly all-original lineup of 14 personality-driven series this summer, three of which will air five days a week.

"The voices from Hollywood will help audiences find the network faster," says channel chief Eileen O'Neill. She says other experts will add a dose of credibility.

That means such shows as "Battleground Earth," which pits Ludacris against Tommy Lee — neither of whom is known for his green thumb — in a series of challenges such as solar-powered racing and bamboo homebuilding.

"That sounds a little out of my element as far as hard labor is concerned," says Ludacris, who says his main environmental contribution so far has been keeping lights turned off and "putting my computer on sleep." But, he says, "I'm willing to do what I need to do to educate America. There's little things I know about, but I feel like there are other things I can learn."

And Grenier, whose "Entourage" HBO alter-ego is a party-hearty movie star, will produce and appear in "The Green Life," which aims "to inspire on an emotional level" his own brand of environmentalism, including refurbishing a Spanish-style home with an ozonated pool and recycled shower water.

"We're attempting to avoid the more boring parts of what this show could be," he says. "We're not a bricks-and-mortar type show. The main focus is how to be creative when you're trying to do things you want to do anyway."

Told that Lee already has dubbed him "Luda the Polluta," Ludacris (aka Chris Bridges) came up with his own nickname for his soon-to-be nemesis (the show begins filming April 16): "Toxic Tommy."

"I was definitely not down to do another reality show, because we have too many of those, and they're stupid," Lee says. "But we're doing something for our kids. (Environmentalism) is a serious sort of subject, but you got to make it fun or you freak people out."

Planet Green replaces Discovery Home, an unsuccessful spinoff channel, and will be available in 50 million of the nation's 110 million TV homes June 4.

In 10-year-old Discovery Home, "they've got a network on their hands that clearly is not working," says SNL Kagan analyst Derek Baine. "If they don't do something to get the image up and deliver viewers, they are in danger of having operators drop the channel (or) move it to a higher (digital) tier."