Monty Don gives his ornamental grasses an overhaul. He has got tips on how to lift and divide ones that have grown too large, plus advice on which ones should be cut back now for the best display in the autumn. He also wants to bulk up his grass borders and gets the ball rolling by sowing some seed now. Rachel de Thame visits the stunning Trebah Garden in Cornwall to revel in their glorious collection of hydrangeas. And Carol Klein returns to Gloucestershire to see how the new gardeners are progressing. She helps them take a huge step forward in creating their garden by laying a lawn. She also helps them prepare their heavy clay soil for planting.