This small Chilean tree justifies its place in the garden all the year round, with handsome tiered branches covered in tiny variegated evergreen leaves. But as winter ends, it begins to waft clouds of vanilla scent from tiny yellow flowers which cover the undersides of the branches. This is one of the most satisfying smells in the world: not a dusty vanilla like the scent of Clematis montana but deep and almost edible, like celestial ice-cream.