Espalier is the art of training a tree, shrub or vine to lie flat against a trellis or wall. If you wish to espalier a fruit tree, choose a cultivar grafted to a dwarf rootstock. It won't make the fruit smaller or the tree less productive, but it will control its size. Once you train the tree to lie flat by pruning and tying shoots to the trellis structure, enjoy picking fruit from your work of art.
Draw your espalier design on paper. Several shapes ranging from freehand to formal can be used; candelabra, fan, diamond or palmate are some of the more formal choices.
Do major pruning of espalier fruit trees in early spring, before new buds appear. Wipe the pruning shear blades with a cloth dipped in rubbing alcohol to kill bacteria, fungus and insect eggs that may be present.
Tie the branches of the fruit tree to the trellis in the form of your design. Use plant ties or soft string that won't harm tender fruit tree bark. Tie them firmly, but not tight.
Prune away branches that don't fit the design. Keep in mind that vertically growing branches on fruit trees tend not to produce fruit. Use pruning shears to remove outward-projecting branches to keep the tree trained flat against the trellis.
Allow branches that are part of the design to grow freely until they reach the length of their part in the espalier. Prune branches at the tips when they exceed that length by a few inches.
Let side shoots grow to 12 inches before clipping them off during the summer. Check the tightness of the plant ties every 6 months and loosen them as branches grow in diameter.
Pinch off leaves and branch tips with your fingers at any time during the growing season as the espalier matures. This will stimulate new growth and help the design fill in over time.
Plant espalier trees 6 to 10 inches from the support structure to give roots enough space to grow and stay aerated.
Don't begin espalier pruning until the tree is established. Major pruning on a newly planted tree can damage its vigour.