John Craven and the Countryfile Spring Diaries team - Keeley Donovan, Jules Hudson and Margherita Taylor - unveil the secrets of spring. Keeley Donovan discovers how just one in fifty people in the UK experiences spring as a truly multisensory experience. And one of the most fragrant and emblematic symbols of spring is under attack - Jules Hudson investigates why native bluebells could be extinct in the space of a generation.