Trees and shrubs are the backbones of any garden, creating a living framework for all the other plants. Deciduous trees change with the season, with beautiful spring flowers or spectacular autumn foliage. Even when the leaves have fallen, the bare branches add height and interest to the winter garden. Conifers add evergreen structure and come in a surprisingly wide range of colours, shapes and styles. Finally, shrubs are the perfect choice for low-maintenance gardens. There are spring, summer and autumn-flowering shrubs, and many of them need an annual trim to keep them tidy.