The term espaliering refers to the training of a tree so that it grows flat. Often this means growing against a wall, but it can also involve training the tree so that it grows laterally along a trellis or simply along wires. The technique allows the tree to grow “flatter”, with more width but less depth. While often used to guide the shape of ornamental trees, espaliering is also a handy technique for use on fruit trees, which are very resilient and responsive to the pruning the method requires. Espaliering is useful for permaculture gardeners with limited space who wish top grow a fruit tree, and for those who want to make use of a microclimate to aid the tree’s growth, by taking advantage of the warmth radiated by a wall that receives direct sunlight, for instance. (Indeed, the technique was first developed in 16th century Europe to help grow fruit trees used to colder climes grow in temperate regions by exposing them to suntraps and warm brickwork.)
Fruit trees that require espaliering are most often those against walls, typically by those who lack space on their plot or who have a courtyard garden. However, espaliering can also be used to train trees that, for instance, divide garden beds. In almost all cases, however, you need to ensure that the fruit tree is in a position to get several hours of sunlight each day. Fruit trees need sunshine to help them set fruit. So if planting against a wall or fence make sure it is one that has an aspect that receives lots of sun.
Most fruit trees will lend themselves to espaliering. Apple and pear trees are popular choices for their robustness and the quantity of fruit they produce even with the pruning espaliering demands. Most citrus trees will do perfectly well trained with espaliering, as will olives and cumquat trees. Ideally you will be looking to buy a tree of a year old, so that it will survive transplanting to your permaculture plot, but will not have developed too many branches. If space is really at a premium, choose a specimen with dwarf rootstock.
Espaliered trees need to have something sturdy on which to train the branches. Even if placed against a wall or fence, you will need to install a trellis or wires so you have something to fix the branches you are training to. If using wires – either against a wall or freestanding – they will need to be held under tension so that the branches can be accurately trained, so ensure they are affixed to strong supports, such as fence posts. As a general rule, placing the wires approximately 30 centimeters apart is good.
Planting a fruit tree that you will be espaliering is the same as for a fruit tree that you won’t. The rootstock needs good soil conditions so that it is healthy and robust and can provide the branches with the nutrients they need from the soil. Fruit trees tend to prefer a well-drained soil rich in organic matter, so add compost to the soil before planting. You will typically be planting a young specimen with rootstock, so dig a hole as deep as the root bell and twice as wide. Place the rootstock in and fill the hole, being careful not to cover any over the trunk, as this can cause it to rot. Plant during the dormant season so the roots can get established in the soil before the growing season, when the majority of the pruning for espaliering, and the setting of fruit, will occur. Do not plant the tree too close to a wall or fence; you need to leave at least eight inches or so between the trunk and the structure to allow space for air to flow around the tree, and for the trunk to grow. Tie the trunk to the support structure so that it grows straight up.
There are several different styles of espaliering that gardeners can utilize. Which one they choose will depend in part espalier-tree-255770_640of the space they have available for their fruit tree, but also on the aesthetic attraction they have to a style. Different styles will take differing lengths of time to achieve, and some will require more work on the part of the permaculture gardener to achieve. Some common styles of espaliered trees include the candelabra, which has several vertical branches growing off a single horizontal. The cordon is a very traditional style, simply with branches trained horizontally from the trunk. Cordons can either have a single branch growing left and right from the trunk or several, spaced vertically. The Palmetto style involves several horizontal branches coming from the trunk, each bending up to a vertical. This forms a concertinaed effect, with the widest branches at the bottom and successive offshoots bending closer to the trunk. You can also choose to espalier your fruit tree more informally, pruning it so that it remains on a two-dimensional plane, but has a more natural look that the stylized versions outlined above.
Whatever style you choose for your fruit tree, it will require work to prune the tree and so “train” it to form the desired shape and fit the available space. When you first plant your fruit tree, prune back the leading branches. This will encourage growth in the lower lateral branches. Clip or tie the lateral branches to the wires or trellis to encourage their horizontal growth. Generally you will need a clip every 20 centimeters or so. Regularly check that the ties do not choke the branches, and that they have enough space to grow in girth. As the tree grows, prune back branches that do not fit your style. You may need to do this weekly, particularly at during the growing season. For the first year in the garden – if you planted a yearling – it is a good idea to prune so as to avoid fruit setting by snipping off nascent fruits so the tree’s energies go into developing string roots and branches. In the third year prune allow fruit to set.
Besides regular pruning to maintain and encourage shape, you need to ensure the fruit tree is well watered, particularly in the summer months. As the dormant, winter season approaches, add fertilizer to the surrounding soil and mulch (leaving clear space around the trunk). This will give the roots nutrients over the winter so that the tree will come back with vigorous growth at the next growing season.