EXCLUSIVE: Secret Garden, the David Attenborough-fronted natural history series that recently rated big on the BBC, is being pitched into the U.S. as a format.

Plimsoll Productions is taking the unusual step of shopping a natural history program to networks and streamers as a format after Secret Garden securing a 30% prime-time audience share and becoming the biggest unscripted launch in the UK this year. The show is also the biggest-rating original British format launch in the past five years.

Natural history shows are almost always sold as finished tapes due to their filming costs and logistical challenges, but the contained nature of Secret Garden means a different approach could be taken. Plimsoll makes the show for UK public broadcaster the BBC, but owns the underlying rights thanks to Britain’s TV terms of trade regulations.

The five-part series launched on BBC One on April 5 and ran until May 3, just five days before Attenborough celebrated his 100th birthday. His centenary was marked by tributes from across the UK and beyond and a number of broadcasts, including David Attenborough’s 100 Years on Planet Earth.

The series was set in five different gardens across the UK, with broadcaster and naturalist Attenborough revealing the lives of the secretive animals that inhabit the hidden worlds within them. The U.S. version will aim to bring viewers into American backyards, from the heartlands to the Rockies and to city skylines, we hear.

Grant Mansfield, CEO of Plimsoll, said: “Secret Garden has been the breakout new unscripted format hit on UK TV in 2026, attracting an audience share of 30%+, retaining audience throughout the series and doubling its audience volume on 28-day digital views. We’re excited to bring this magical, uplifting and revealing family show to the States where garden secrets are even more amazing and a whole lot bigger.”

Plimsoll is a natural history specialist through shows such as Disney+’s Awakwafina-narrated A Real Bug’s Life and ITV’s Stephen Fry-fronted A Year on Planet Earth. It also made headlines last year through Netflix’s event program Skyscraper Live, which attracted 22 million viewers worldwide and one billion social media impressions.

Rolling out soon are Pompeii Out of Time with Tom Hiddleston for Disney+ and Force of Nature for ITV.