2. Wisley Plant Centre RHS

"Superb quality, as you'd expect from the Royal Horticultural Society's own garden centre, with the emphasis firmly on plants rather than seasonal tat," says Anna. "Magnificent magnolias and fabulous ferns – choose from 9,000 different delights and next door is the best gardening bookstore in the world."

Where: RHS, Wisley, Woking, Surrey, GU23 6QB (01483 21111; rhs.org.uk/wisleyplantcentre)