Generally, fruit trees are pruned during winter, but certain trees like trained forms or stone fruit require summer pruning. Summer pruning increases the light available to developing fruit, leading to greater size, improved colour, and sugar content. It can also encourage fruit buds to form, leading to greater yield in the following year.
Importantly for trained forms like espaliers or fan-shaped trees, summer pruning reduces vigour, which helps with keeping the tree in its restricted form. It is important only to prune stone fruits like plums, cherries and apricots in the warmer months between May and July, as outside these times they are at greater risk of contracting Silver Leaf fungal disease.
How to prune espaliers and trained forms
Trained forms are fruit trees that are manipulated to grow according to a particular shape, such as an espalier, which grows along a wall or fence. These trees require summer pruning to reduce vigour which will help keep it in its restricted form. The system commonly used in Britain is known as a modified Lorette.
Wait until the base of new shoots have turned woody and growth has slowed (in the South-East this should be around mid-August and later further North). Shoots will be darker in colour and less bendy and you will notice terminal bud forms on the ends.
The horizontal framework branches will have lots of new spring growth coming off them, which all needs to be shortened to allow light in. New shoots coming straight off the main branch (laterals) should be cut back to three leaves above the basal cluster (the closely packed set of leaves right at the base of the shoot). Any shoots growing from these laterals (sub-laterals) should be cut back to one leaf.
Cut back to one leaf on a sub-lateral (see below). Shoots that are shorter than your secateurs (about 9 inches) should be left on, as they are likely to have fruit buds on them.
The ends of the main branches should be tied in to prevent them growing upwards – while still growing tie them loosely at an angle – and tie in horizontal once the growth has stopped. This is to ensure the growing shoot draws up enough hormones to create a strong branch.
Prune all side shoots to 2-3 leaves and once the leader reaches 6 feet, prune it to one leaf from the start of the new growth to keep the tree within easy reach for harvesting.
Pruning established trained stone fruit
In June, tie in any suitable shoots if there is room in the framework. Cut back remaining new shoots to six leaves from the basal cluster. Any misplaced or damaged shoots may be cut out altogether. After fruiting in the summer, cut shoots again back to three leaves. This will help to create a spur that will bear fruit next year.
Bush trees & renewal pruning
Renewal pruning is the system used by commercial orchards and is relatively simple to master. A tree is grown with 4-5 permanent structural branches which produce side shoots. These are left untouched for around four years and then cut out entirely and replaced by new shoots. This is based on the premise that the wood in fruit trees is most fruitful for up to five years.
Apple and pear trees should have the main restorative or structural pruning done in the winter when the tree is bare and the shape is easier to see. At that time of year it is also easier to distinguish between fruit and leaf buds and avoid cutting off too much productive wood.
Pruning in summer helps restrict unwanted and excessive growth that occurs after winter pruning and aids with current and future year’s fruit production. Apples and pears that were pruned to an open-centred form the previous winter have put out lots of young new growth that needs cutting out to allow air and light into the ripening fruit.
If you were overly enthusiastic with your pruning last year you may have lots of these upright shoots – thin them out to three or so, looking to retain any that are less upright which may be encouraged to more open, downward growth.
Prune no more than 20% of the tree’s wood and focus on upright, vigorous shoots, crossing branches or damaged/diseased wood.
Plum trees have a more congested growth habit and branches that naturally tend to droop downwards. Less pruning is required and should be focused on keeping the tree to a manageable size, reducing the worst branch congestion and removing any damaged or diseased wood.
Any branches that have grown straight up with no sign of curving down can be taken out at the base. Then cut back any over-extended branches or those trailing on the ground to a side shoot or a fruit. Cutting back to where there is fruit will help slow down renewed extension growth as the tree will direct hormones to the fruit.
Once your summer pruning is done, check out these other guides on fruit tree pruning:
Find our guide for pruning apple trees in winter here.
Find our guide for pruning veteran trees here.