Pruning fruit
Pruning is done for a variety of reasons. Some trees are pruned to a specific shape and size to encourage fruit production. Others only fruit on new wood therefore pruning is essential to encourage new branches to grow. Pruning maintains a tree’s health by removing dead or diseased wood, which in turn encourages healthy new growth. When trees become too dense or tangled, pruning opens them up, creating airflow and reducing disease. Pruning can also be done to encourage a tree to grow into a specific pattern. If a tree produces excessive amounts of young fruit, thin these out selectively. The remaining fruit will be healthier and bigger. Thinning, or even removing fruit completely, during a fruit tree’s first two to three years will encourage new growth and establish strong limbs.
Pruning should be done when the tree is young, from its first winter. Pruning stimulates new growth and by selecting which branches we want to grow, we can shape the tree into a strong frame that will support fruit. This should be repeated every year in June or July, until the shape is established, which will take about three years to achieve. In subsequent years, maintenance pruning should be done to keep the shape by selectively removing trunk and branch suckers. Remove any crossing branches or diseased limbs. Although sealing cuts with a pruning seal used to be common practice, these days most gardeners prefer to leave cuts open to the air to seal naturally.
Pruning Techniques
When a branch is cut off, the tree forms a protective layer – like scar tissue – to cover the cut, preventing disease and decay. Correct pruning will assist the tree in doing this efficiently. Cuts must be clean with no tears in the bark, which can lead to disease. One of the first principles of pruning is to have sharp, well-maintained tools. A blunt saw or secateurs will result in tears and the branch being crushed instead of cut. When pruning, avoid creating snags – short pieces of branch sticking out from the stem or beyond a bud. These most often die back, leaving dead wood, which is an invitation for disease. Cuts of smaller branches should be made tight against the stem or, if removing the end of a shoot, just above a bud.
A bud cut should be made at an angle away from the bud, allowing water to drain away, reducing risk of rot.
Cutting through a larger, heavy branch should be done using three cuts. This prevents its weight causing it to fall before you have finished cutting, thus tearing the bark open along the branch and sometimes down the trunk, which is an invitation for disease.
Make the first cut (1) about 60 – 90 cm away from the trunk, cutting in an upward direction, only cutting about a third of the way through. This will prevent the bark splitting to the trunk. Make the second cut (2) about 8 cm further out from the first cut and cut all the way through. The final cut (3) is the most important – especially when pruning a large branch. If you look at a branch, you will see a swollen ring or collar where the trunk bark transitions into a smooth branch (4). The final cut should be made following the angle of this collar, cutting the branch flush against the collar, but not cutting into it - the branch collar forms the scar tissue and if it is removed, the cut will not heal properly.
An Open Vase
This method of pruning shapes a tree to a short trunk with three or four main (scaffold) limbs, each with several lateral branches, radiating from the trunk at a similar level, like spokes of a wheel. A vase shape creates an open centre, allowing light and air to reach all the branches. It is ideal for smaller gardens, keeping the tree low for easy harvesting and care. It also encourages fruiting on lower and interior branches. It is suitable for most deciduous fruit and trees in containers. In larger gardens the open vase shape can be modified by allowing the tree to grow taller, with alternating scaffold branches radiating out at different levels, but still maintaining an open centre. The illustrations below show two layers, pruned in an open vase shape.
Year one: Choose three or four main branches that are evenly spaced around the trunk. Prune the central leader and any other side branches.
Years two and three: Prune the end of each branch to an outward-facing bud. This encourages strong growth at the end and establishes the shape. Remove branches in the centre of the tree, keeping the central vase empty. Remove any crossing branches.
Maintenance
When you have learned the basics of pruning, it is not difficult to keep on top of it. After establishing a good structure, annual pruning consists of cutting back about two thirds of the previous season's growth. Don't overdo it otherwise the tree will start producing water shoots (unproductive long shoots that grow straight upwards). Also remove any dead, diseased or damaged branches. Cut off any branches that are crossing over others or are at too close an angle to another branch. Remember - you are aiming to keep sunlight in and to give all the branches space to produce fruit. When making a choice between two branches, always choose the one that is more horizontal, as this will produce more fruit.
Once established, most fruit trees are relatively hassle-free, and don’t need much other than regular watering and feeding when required. One of the products that I use regularly on my fruit trees is Talborne’s Vita Fruit & Flower. This organic fertiliser has been formulated to provide a balanced supply of nutrients to fruit trees.
When feeding dry fertiliser, it should be applied to the ground under the drip line of the tree and watered in well. The drip line is the outer edge of the tree, where the furthermost branches are. A tree mirrors its upper growth in its roots, with the newest and most efficient roots being quite far away from the trunk. This is where you want the fertiliser to go. Tip: if you have dogs (who love eating fertiliser!), use a fork to poke holes in the ground all around the drip line. Put the fertiliser in the holes, cover them up and mulch well. Liquid fertiliser can be sprayed onto the leaves as a foliar feed or used as a drench onto the soil. This is useful if a plant is struggling, or to give it a boost after fruiting.
Many fruit trees are grafted onto root stock of another variety. This is done for various reasons. Some cultivars do not grow true from seeds and can only be reproduced by grafting. Other reasons include: to produce dwarf varieties; to increase disease- and pest-resistance; to create a tree with two or more varieties on one trunk; or to increase hardiness, sturdiness and strength. One thing to watch out for on grafted trees is for growth coming from the root stock. Called sucker shoots, these unproductive stems need to be removed, as they will pull energy away from the fruiting sections and create unwanted growth. There are two ways in which you can identify these. Firstly it will be coming from below the grafting point – a bumpy section, low on the stem. Secondly, it will look different to the upper section, with dissimilar leaves or larger thorns, for example.
