It's early spring in Kew Gardens and daffodils, crocuses and magnolia are bringing out the visitors in search of the first colour of the year. Also making a fresh start is Simon, the new head of living collections, and he's got the massive job of evaluating nearly 17,000 different plant species in the gardens to decide what stays and what goes. Meanwhile, Paul is doing a health check on the tuber of a dormant titan arum, a perennially popular plant that produces a huge flower that smells of rotting flesh. Kevin is also embracing change as he takes over as Kew's chief tree guardian, head of the arboretum. He's using sophisticated technology to see what is happening inside some sickly trees… that is, if the £5,000 computerised sonic hammer behaves itself. The 10-storey royal pagoda reopens for the spring season, and we get a guided tour with Rachel from Historic Royal Palaces. She tells us all about its history, from being a playground for Princess Augusta in the 1700s, through being use