Paltrow's mom says the pair are "inundated," so they work hard to stay out of photos together
Credit: Brad Barket/Getty; Evan Agostini/AP

Gwyneth Paltrow‘s mother, Blythe Danner, is setting the record straight on recent rumors that her daughter’s marriage to Coldplay frontman Chris Martin is in trouble.

“Oh no! They are really happily married,” Danner told PEOPLE Thursday at an unveiling for Energy Vision natural gas garbage trucks in New York. “They are together all time. The public just does not see them together. They couldn’t have a better marriage.”

Paltrow, 35, who has been married to Martin for four years and has two children, is rarely photographed with her husband in public, and the Oscar winner (who herself called the rumors "ridiculous") says the public will never see the couple out publicly.

And the reason why? “It has to do with being so inundated,” Danner explains. “They get so inundated and it’s gotten so awful now that they can’t go out and enjoy themselves. If they were both out together they would just get so overwhelmed and not enjoy themselves. So they do it for that reason.”

With so much speculation, Danner says it’s something she recently started to hear herself. “It’s just so silly that people have to make a great big thing about it. It’s just their way of being private and you’ve got to respect that. I guess they feel that being apart in the public will cause less heat.”

Gwyneth’s Childhood Activism

Just in time for Earth Day, Danner, 65, helped unveil new energy-efficient natural gas garbage trucks in New York City’s Union Square. For the actress and longtime activist, she says her work paid off with Gwyneth and her grandchildren, Apple, 3, and Moses, 2.

“Gwyneth was actually 3 years old when she had a placard that we made, this homemade sign that said ‘You are Polluting.’ And we would ride around Los Angeles where we lived,” Danner adds. “I said, ‘Gwennie, when you see dirty, black spewing out of a bus or a truck, hold up a sign.’ ”

After delivering the instructions, the mom-and-daughter team had a scary moment – when the young Gwyneth proceeded to roll down her window at a stop light. “Before I could stop her, she was saying to this big guy in this huge truck, ‘You’re polluting!’

“He said, ‘I am? I better go to the big garage and fix that.'”

Composting with the Grandkids

As for her grandkids, Apple and Moses “compost with me,” Danner says. “It’s a nice thing we like to do together out in our garden. They are great helpers.”

“Apple said to me the other day in the car, ‘You know we have to keep the world clean.’ and I said, ‘Yes! That’s my girl!’ She is getting the message.”

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