The National Trust needs to attract younger members, the conservation body’s chairman has said as it celebrates its 125th birthday.

The Rodbourne-based organisation which cares for countryside, coasts, castles and stately homes hopes to get its sixth million member this year.

Tim Parker told the Sunday Telegraph: “The trust only succeeds if it’s able to attract new younger people and we are striving to appeal to them.

“I think younger people are interested in history, in beautiful things, they do enjoy gardens and they enjoy going outdoors. There’s no inherent reason why it should be something for middle-aged people.

“It’s been shown that when people get out in nature, it’s not just the physical benefits they enjoy but the mental benefits as well.”

Mr Parker added that he is “up for appealing to every kind of gender and sexuality" and wants to help get people off their mobile phones and into the outdoors.

The National Trust is also planning for the next 125 years, including by tackling climate change. It announced last week that it would be carbon neutral by 2030 and would plant 20 million trees over the coming decade.

“Protecting nature and giving nature a chance, trying to reduce our carbon footprint as quickly as possible, I think those are the challenges that we have set ourselves,” Mr Parker said.

The trust is also the biggest landowner in the country but it will take on more terrace houses than stately homes in the future as visitors are fascinated by “real people’s lives”, he said.