Apricot espalier: training and pruning

Apricot espalier: training and pruning

Depending on the climatic conditions, apricots are frequently grown against protected house walls. Apricot espaliers are often planted on East, South or West-facing house walls. West-facing walls are particularly recommendable. However, it is important that no rain can reach the blossoms or leaves and that the apricots are protected against cold winds. Owing to the heat radiated from the house wall, it can be assumed that the temperature here is one or two degrees warmer than the air temperature.

Planting
Correct espalier cultivation is a significant factor for the future yield and above all for the quality of the apricots. It is best to plant the apricots in the late autumn. For the subsequent growth, however, the most important prerequisite is that the wood of the trees is sufficiently mature. The greatest problem with young trees is that they are uprooted too early in the nursery. These trees are often unable to survive the winter in some parts of Europe. Apricot trees should therefore not be uprooted in the nursery before the end of October. The wood is then mature and can easily survive the winter.

Correct training
Pruning should be performed in the spring. In this first step, the foundations are laid for the future crown formation. A central shoot and two leader branches are required. The leader branches are located at a 45 degree angle to the left and right of the central shoot. Leader shoots that project too steeply must be spread out and those projecting too horizontally tied to the centre shoot. Leader shoots are generally cut back between half and two thirds of their length at an outward-facing bud eye. The length of the pruned leader shoots should not exceed 30 to 40 centimetres. The centre shoot is left about 10 centimetres, roughly a hand's width, longer. The leader branches are trimmed back every year until the tree reaches its final length and the fruiting branches are grown on the remaining leader branches. All the competing shoots are removed.

Apricots fruit on one-year old branches. Young shoots which have grown the previous year bear blossoms and fruit the following year. Long, one-year old shoots are removed from the espalier. The short, one-year old shoots are generally trimmed back to achieve a better leaf-to-fruit ratio. One shoot every 10 to 15 centimetres is sufficient. All the superfluous shoots are therefore pruned back to one bud eye. During the course of the vegetation period, a young shoot develops from this bud. This is a very effective method for preventing sparseness.

Pruning times
When shape-pruning, it is essential that the centre shoot, the leader branches and the fruit-bearing branches are only pruned back during winter pruning. The extent of the pruning always depends on the development state of the leader shoot. The weaker the growth of a leader shoot, the more it has to be pruned back. The stronger the growth of a leader shoot, the less it needs to be pruned back. During training, we need growth. We can achieve stronger shoot growth if the shoots are pruned before budburst. Leader shoots must be trimmed back to at least one cutting plane (open vase). The centre shoot should be one hand's width longer than the leader shoot. The ideal pruning time is shortly before the start of vegetation. In the case of trees which have completed the training phase, the blossoming shoots can still be pruned. Pruning back too early in the winter months could lead to crop failure.

Summer pruning
In years when crop failure occurs owing to frost damage to the blossoms and the shoot growth develops strongly as a result, the thick shoots should already be removed from the middle of August. This ensures that shoot growth is more moderate the following year.

Pinching out apricots
Apricots fruit on one-year old wood, on short shoots or on the last third of a long shoot. For this reason, as soon as shoots have developed 10 to 12 new leaves, they should be trimmed back to 4 to 8 leaves. Leaves at the leaf base (leaf rosettes) are not counted. This ensures that the blossoms develop on the first third of the shoot and not on the last third.

If more than 12 leaves have developed and the shoot is pruned back too late, there is a risk that the blossoms can no longer form. So it is not the month, but the stage of development that is decisive when pinching out. Depending on the location and weather, this occurs in May or June. Central shoots and leader shoots must not be pinched out as these are responsible for crown formation and not for bearing fruit. Owing to the varying shoot development, pinching out cannot be performed in a single operation. The shoots should be trimmed back using loppers. On no account must the shoots be snapped off and left hanging on the tree because this promotes diseases. The new shoots can be trimmed back again to two leaves around the end of August, provided the growth is not too heavy. In the case of a heavy budburst, this can also be taken care of during winter pruning.

If the shoots are pinched out conscientiously, only corrective pruning is required in the spring, which is then mainly limited to thinning out and removing dead wood.

Manfred Putz
VIKING garden expert