In winter, there are fewer tourists at Buckingham Palace, but Alan Titchmarsh discovers all manner of animal visitors to the grounds as he installs hidden cameras in trees and bird boxes. As spring arrives early, he learns about the garden's role as a nursery, not just to young animals but also to young royals. In late May, a transformation takes place - a tented village on the lawn is a sign that party season is coming, and the race is on for the gardeners to put the finishing touches to 12 months of work. The programme ends with the climax of the year, as the Queen attends a garden party to greet her guests.