Sweet, sour, or weeping cherry trees are planted by many home gardeners for their beauty and delicious fruit yield. Like all fruit-bearing trees, cherry trees require careful pruning to ensure the health of the tree. Whether a young or mature cherry tree, knowing when and how to prune maintains the structure of the fruit tree, opens up air circulation, prevents disease and stimulates a quality fruit yield.
Removing certain branches and shaping young and mature cherry trees is necessary for allowing sufficient sunlight to reach the entire tree. Pruning is also done to remove damaged or diseased branches and to thin out growth. In addition, pruning young cherry trees stimulates early fruit production. The only way to achieve a strong, yielding tree is through pruning. Pruning of fruit trees is also necessary to create strong limbs that can hold the crop without breaking. Cutting away some tree branches also ensures a good harvest in terms of size and quality of the fruit.
When to prune
Cherry trees need pruning every year. Although most fruit trees are pruned once the tree is dormant, sweet cherry trees should be pruned in August to minimise the chance of bacterial canker, a common tree disease that forms on open pruning wounds. Sour and weeping cherry trees can follow the traditional schedule of fruit and nut tree pruning and be pruned as soon as the risk of winter freeze passes. This time frame prevents the chance of silver leaf disease. Early spring is also the time for pruning young cherry trees. This allows you to shape and train the tree before it begins to bloom. Mature cherry trees can be pruned in early spring or right after they bear fruit.
How to prune
While weeping cherry trees should be pruned to follow their growth design, an open centre is the desired shape for sweet and sour cherry trees. It takes four growing seasons to achieve an open centre pruning shape and the process should be started when the tree is young. During the first pruning season, remove all but four shoots which will become the main scaffold branches. Select branches that are 20 cm (8 inches) or more apart on the tree trunk. During the second and third pruning season, select one or two more scaffold branches. By the fourth pruning season, the tree should be showing an open centre shape, with branches growing evenly around the tree trunk. Prune away any additional branches to achieve the shape.
As the tree matures, prune away any non-producing shoots growing on the main branches. If the tree is not producing good quality fruit, consider pruning shoots at the end of branches. You might also need to cut back branches at the top of the tree to decrease its height.
When pruning, make cuts on an angle and flush with the tree to avoid any damage to its trunk. Common pruning tools for cherry trees are a pruning saw, a buck saw, or a rope saw.