Espalier is art of pruning and training trees or shrubs usually against a wall or trellis to form symmetrical and flat geometric shapes. Training trees into flat, two-dimensional shapes has more value than just decoration of walls and gardens. Espaliered trees are perfect for lawn and gardens with limited space. When grown against walls, they reflect sunlight and protect the wall from heat waves.
There are a number of techniques and methods to train and transform shapes in to flat espaliers. With a little practice, you can craft interesting shapes out of your shrubs and trees. Get started with some simple espalier techniques given here.
Here are a 10 amazing examples of espaliered trees for your inspiration.
If you need further information on designing and caring for espaliers, I would highly recommend Karl Pieber’s book: Espalier Fruit Trees for Wall, Hedge and Pergola.