Espalier tree training features in European gardens in both formal and informal styles. Very old espalier fruit trees can be found growing on old brick and plaster walls in gardens in France. This method of tree training is attracting interest with New Zealand gardeners keen to create a compact and attractive tree feature.
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, while still retaining sunlight and visibility.
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 to the age of wood the fruit is borne on. For more information see the Fruit Tree Physiology section (below).
Step 2: Choose a location. Most fruit trees need a minimum of 6 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, in general, semi-dwarf or vigorous rootstocks should be used in all but the most fertile soils. For clay soils, select rootstocks that perform well in this soil type. In highly fertile soils with irrigation, dwarf rootstocks can be used. Selection of disease-resistant varieties will ensure minimal spraying is required.
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 (the latter used in the instructions below). With fences and walls, fix the wires using eyebolts to keep the plant away from the structure. Incorporating turnbuckles to keep the wires taut is recommended.
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 instructions below for the most common espalier patterns.
INSTRUCTIONS FOR A TRIPLE HORIZONTAL CORDON
For apples, pears and nashi.
1. In spring, cut the whip or leader to where you want the lowest set of branches to form - usually at the first wire.
2. The tree will branch out from where you have cut it back. Select the best three sprouts and pinch off the rest.
3. When two of the sprouts grow 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.
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 2, selecting and tying horizontal sprouts, leaving one to grow vertically to the next wire.
5. As the horizontal shoots grow, continue attaching them to the wires. Pinch off shoots that grow toward or away from the wall. Prune frequently and lighting.
INSTRUCTIONS FOR A FAN ESPALIER
For stonefruit, quinces, berries, citrus, figs and persimmons - types that don't produce fruit on spurs.
1. In spring cut the whip or 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.
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.
3. Refer to the Fruit Tree Physiology section below regarding renewal of fruiting wood from the main branches. Branching off the main limbs will produce the fruit. With many fruit types these branches will need to be removed and renewal branches selected after fruit has been produced.
A SHORT LESSON IN FRUIT TREE PHYSIOLOGY
It is important to understand the natural needs and growth of fruit trees when undertaking an espalier, to produce a productive and ornamental tree.
The most difficult forms to create are those with horizontal branches. Sap moves easily up a vertical trunk or branch, stimulating rapid vegetative growth and elongation of the branch. As a branch is trained away from the vertical, the flow of sap is progressively braked. This has two effects - slowing down of vegetative growth, and stimulation of fruit bud production - both good effects. By training a branch horizontally, it will stop growing entirely - so you need to trick the branch by keeping the growing tip bent upwards.
To ensure the branches elongate, it is important to rub off the fruiting buds during the early training stages.
When selecting the fruit tree type and pattern of your espalier(s), it is important to consider what age wood the fruit is borne on. As apples & pears produce fruit on the same wood year after year, a formal, static pattern can be chosen. However, as stonefruit, citrus, figs, persimmons and berries produce fruit on one or two year old wood, renewal of fruiting spurs is required. Therefore a fan/palmette espalier is the most appropriate pattern for these fruit types. In this type of espalier, the fruiting branches grow from the main branches. These are removed after fruiting, with new fruiting branches allowed to grow each year. Due to the need to promote the renewal fruiting secondary branches, a formal espalier pattern is not appropriate for these fruit types. Another reason for choosing the fan pattern for these fruit types is that some of the branching is particularly strong, making the 90 degree bends of formal espalier patterns difficult to achieve.
As you get more and more into your espaliering, you will learn to recognise and understand the different types of buds (vegetative and fruiting) and the branching patterns of your trees.