Espalier trees are trained to grow on a flat plane, usually against a trellis or fence, instead of three dimensionally. Most plants can be trained in this fashion, but fruit trees such as apple and plum are the most common espalier trees. To train an espalier fruit tree, start with a very young tree and train the branches when they are still new and flexible. Training an espalier tree can take five to seven years, and complex woven patterns will require regular maintenance.
Plant your fruit tree along a south or east-facing fence or trellis, in a six- to eight-inch hole. If you want a smaller tree to grow along a short fence, choose a dwarf variety.
Gently bend the branches against your flat plane and tie in place with string or pantyhose. For a natural design, train the branches against the fence in the shape they naturally grow, making sure the branches do not overlap when you tie them in place. For complex woven patterns, prune unnecessary growth and position branches in your desired design before securing them with string.
Loosen the string to allow for growth as the branches get larger, and tie new growth to the trellis. Remove flower buds during the first training season to encourage faster growth. This means your tree will not produce fruit in its first season but will reach your desired shape faster.
Prune large growth in the winter, during the tree's dormant phase. Young trees should be pruned later in the winter, when there is less chance of injury from cold weather. Apple trees can be pruned earlier than plum or peach trees, but the later you prune the safer your trees will be. Choose a time late in the winter when the harshest weather has passed but before new growth begins in the spring. Remove branches that grow away from the trellis or fence, and any branches that grow straight upward. Use sharp gardening shears to make angled cuts so the water runs off the surface, away from the tree.
Prune new growth in the summer to discourage excessive expansion. Limit summer trimming to young shoots or branches that are less than three months old. Stop pruning at the end of July to allow the tree to fully heal before the first frost.
After four or five years your tree will reach maturity and the main branches will stop growing. At this stage your work is basically done. Continue minor pruning to maintain the shape, and provide water and fertiliser according to needs of your particular tree.
Many fruit trees require cross pollination to produce fruit, so you will need at least two different types of trees. For example, if you want your apple tree to produce fruit, you will need two different varieties of apple trees (one can be a crabapple tree if you only want one tree's worth of edible fruit) planted between 15 and 100 feet apart.