A gardener waters plants inside the newly restored Victorian Temperate House which has been re-opened to the public following a five year restoration programme in Kew Gardens, London, Britain, May 3, 2018.

A gardener waters plants inside the newly restored Victorian Temperate House which has been re-opened to the public following a five year restoration programme in Kew Gardens, London, Britain, May 3, 2018. REUTERS/Toby Melville

People stand inside the newly restored Victorian Temperate House which has been re-opened to the public following a five year restoration programme in Kew Gardens, London, Britain, May 3, 2018.

People walk inside the newly restored Victorian Temperate House which has been re-opened to the public following a five year restoration programme in Kew Gardens, London, Britain, May 3, 2018.

Visitors stand on the Treetop Walkway to view the landscape at Kew Gardens in London, Britain, May 3, 2018.

A gardener works in front of the newly restored Victorian Temperate House which has been re-opened to the public following a five year restoration programme in Kew Gardens, London, Britain, May 3, 2018.

A visitor cycles past the newly restored Victorian Temperate House which has been re-opened to the public following a five year restoration programme in Kew Gardens, London, Britain, May 3, 2018.