Monty Don catches up on his vegetable garden and harvests potatoes, before seeking advice on how to install a water feature in his paradise garden. Frances Tophill helps to erect a greenhouse out of recycled materials on her shared allotment, Joe Swift visits a classically designed garden with a contemporary edge in Northamptonshire, and Juliet Sargeant heads to Borde Hill Garden in West Sussex to see how this year's hot weather caused a rare tree to flower for the first time in 30 years.