Peter and the panel are at the John Innes Centre in Norwich. Bob Flowerdew, Matthew Wilson and Christine Walkden answer the horticultural questions. This week, the panellists help a listener hoping to camouflage a treehouse with plants, they give encouragement to a non-flowering Bird-of-Paradise plant, and they diagnose a rather black tomato plant. They also advise on attracting worms into your compost bin, suggest why perennials aren't flowering this summer, and assist a gardener on a mission to create his own cultivar. Peter Gibbs pays a visit to Dr Scott Boden, Project Leader of Crop Genetics at the John Innes Centre, to discover how LED lights are used to accelerate the growth of plants. Produced by Darby Dorras Assistant Producer: Hester Cant A Somethin' Else production for BBC Radio 4.