Growing Espaliered Fruit Trees and other Shrubs By Catherine Smith A brief background on the ancient art of espalier. "Espalier originally referred to the frame or trellis on which the plant was trained. Today, espalier refers to both the plant and the horticultural technique of actually training the plant. And is seeing a revival of interest as it allows one to grow large quantities of fruit in a small space and for its architectural aesthetics in the landscape.