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 used for testing bombs in World War II, to the cutting-edge restoration that has returned dragons to its rooftop and the whole structure to its former glory. Alberto shows us spring in the glasshouses, and we see the unusual emperor alcantarea go out in a blaze of glory. It grows two metres in two weeks and then produces strange spikey flowers for the first time in its 20-year life — but this is the last thing it does before dying. Meanwhile, at Kew's sister site Wakehurst, conservation supervisor Steven is keeping ancient skills alive: he's coppicing the trees and using the wood to create hedgerows. Leaping into the 21st century, Chris is making a withdrawal from Wakehurst's high-tech Millennium Seed Bank. He is thawing deepfrozen seeds for Alice in the nursery, who brings them back to life and takes the resulting coastal plants down to the Brighton seafront as part of a multimillion-pound effort to return lost plant life to the area.