Gardeners' World has all the tricks of the trade on roses. Looking forward to abundant, fragrant blooms in the summer, Toby Buckland is planting climbers and ramblers around a new pergola at Greenacre. It's also the ideal time for pruning roses and the Royal Horticultural Society are demonstrating perfect pruning techniques from their rose garden at Hyde Hall. Joe Swift joins Toby in the garden and starts work on maintaining the prairie border. He cuts back ornamental grasses as well as dividing the perennial sunflower Lemon Queen. At Glebe Cottage, Carol Klein delves into the roots of the iris family and explains how their varied and sophisticated root types give important clues as to the environments they will thrive in. She is also in the potting shed showing us which members of the iris family we could be planting now for a spectacular show of colour in summer.