All fruit trees require training and pruning to develop proper shape and form, to yield high-quality fruit and to live significantly longer. It is important to begin training and pruning from planting to ensure good development and growth.
Pruning vs. Training
Historically fruit tree form and structure has been maintained by pruning. Tree training is a much more efficient way to develop form and structure. Pruning is the removal of a portion of the tree to correct or maintain tree structure. Training is a relatively new practice in which tree growth is directed into a desired shape. Training young fruit trees is essential for proper tree development. It is better to direct tree growth with training than to correct it with pruning. Training includes summer training and summer pruning as well as dormant (winter) pruning. The goal of tree training is to direct tree growth and minimise cutting.
Dormant pruning increases the vigour of the tree and vegetative growth, which is usually not desirable. Pruning should begin as late in the winter as possible but before the sap begins to flow.
Summer Pruning and Training
Pruning normally starts after vegetative growth is several centimetres long with the removal of unwanted shoots. Main shoots and branches should be encouraged to grow where required by using weights and ties. Remove or trim back new growth to promote the desired shape of the tree.
Central Leader Training
A central leader tree has one main, upright trunk with whorls of branches, usually beginning 60–90cm above the ground, then again every 45–60cm up the trunk. The shape of a central leader tree is like that of a Christmas tree, where the lowest branches are the longest and the branches get shorter higher up the trunk.
Open Centre or Vase Training
With the open vase system, the leader is removed and three to five major limbs are developed as the basic shape of the tree. This training system allows for light penetration.
How to Espalier Fruit Trees
Espalier trees are often grown against a wall, traditionally brick or plaster, but wires between posts can be used to support and train the tree. Using this method the tree creates a part-wall, perfect for dividing areas of a garden or edging a kitchen potager, but sunlight and visibility are maintained.
Getting Started with Your Espalier Fruit Tree
Step 1: Plan your pattern. It is important to consider the type of fruit tree when planning the pattern as it is important to know what age of wood the fruit is borne on.
Step 2: Choose a location. Most fruit trees need a minimum of six hours of direct sunlight, so a north facing situation is best.
Step 3: Choose the plant and appropriate rootstock. As most espaliered trees are subjected to intense pruning and ‘braking’ of growth with training, semi-dwarf or vigorous rootstocks should be used.
Step 4: Prepare the support. You will need to fix horizontal wires to a structure that will support your espalier. These will be used to train the branches at desired angles. Wires can be spaced 30 to 60cm apart. With fences and walls, fix the wires using eyebolts to keep the plant away from the structure. The incorporation of turnbuckles is recommended to keep the wires taut.
Step 5: Plant your tree. Set the plant in the ground about 30cm from the wall, fence or post structure.
Step 6: Start training your tree. Use the following instructions for the most common espalier patterns.
Instructions for a Fan Espalier
For stone fruit, quinces, berries, citrus, figs and persimmons – types that produce fruit on new wood.
Step 1: In spring cut the leader to where you want the lowest set of branches to form – usually at the first wire. Wires should be as close as 15cm apart.
Step 2: The tree will branch out from where you have cut it back. Select the shoots required to make your fan shape pattern. Train these shoots up bamboo canes tied between the wires.
Step 3: Branches off the main limbs will produce the fruit. These branches will need to be removed and renewal branches selected after fruit has been produced.
Instructions for a Triple Horizontal Cordon
For apples, pears and nashi – trees that produce fruit on older wood.
Step 1: In spring, cut the whip or leader to where you want the lowest set of branches to form – usually at the first wire.
Step 2: The tree will branch out from where you have cut it back. Select the best three sprouts and pinch off the rest.
Step 3: When two of the sprouts have grown to about 7.5cm long, make them the horizontal arms and begin tying them along the bottom wire. Make sure to use material that will not damage or restrict the growing branches.
Step 4: Let the other sprout grow vertically to the next wire (you may need to use a bamboo stake), and cut it off again. Once this vertical limb has sprouted, repeat the process from step 3, selecting and tying horizontal sprouts, leaving one to grow vertically to the next wire.
Step 5: As the horizontal shoots grow, continue attaching them to the wires. Frequently pinch off shoots that grow toward or away from the wall.