How To Prune Cherry Trees

When is the best time of year to prune my cherry tree?

The ideal time to prune your cherry tree is in late winter or early spring, just before bud break. This timing allows the tree to heal quickly from pruning cuts and minimizes the risk of disease. Avoid pruning in late summer or fall, as this can stimulate new growth that won't have time to harden off before winter, making it susceptible to frost damage.

Pruning in late winter leverages the tree's dormant state. The tree isn't actively growing, so it won't expend energy trying to repair wounds during a time when resources are scarce. As the weather warms and spring approaches, the tree is primed to direct its energy towards healing the pruning cuts and developing new growth in the desired areas. This results in a healthier, more productive tree. Sweet cherry varieties, in particular, are prone to silver leaf disease and bacterial canker. Pruning during the dormant season minimizes the risk of infection because the pathogens that cause these diseases are less active in cooler temperatures. Ensure your pruning tools are clean and sharp to make clean cuts and further reduce the risk of disease transmission.

How do I prune a young cherry tree to establish a strong structure?

Pruning a young cherry tree focuses on creating a strong central leader and well-spaced branches for optimal sunlight penetration and fruit production. The goal is to establish a framework that can support heavy fruit loads in the future while maintaining tree health and vigor.

To achieve this, prioritize pruning during the dormant season (late winter or early spring before bud break). The first year after planting, select a single, strong upright shoot to be the central leader and prune back any competing shoots. In subsequent years, focus on selecting 3-5 well-spaced main branches that originate from the central leader at wide angles (ideally 45-60 degrees). These branches should be spaced at least 6-8 inches apart vertically along the trunk to allow for adequate light penetration and air circulation. Remove any branches that are growing inward, crossing, or rubbing against other branches, as well as any suckers growing from the base of the tree. Prune back the selected main branches by about one-third to encourage lateral branching and fruit bud formation. When pruning, make clean cuts just outside the branch collar (the slightly swollen area where the branch joins the trunk). Avoid leaving stubs, as they can attract pests and diseases. For larger branches, use a three-cut method to prevent tearing of the bark: first, make an undercut a few inches from the branch collar, then make a second cut from above, slightly further out than the undercut, to remove the bulk of the branch. Finally, make a clean cut just outside the branch collar to remove the remaining stub. With careful pruning in the early years, you can establish a strong and productive cherry tree that will provide years of enjoyment.

What's the difference between pruning sweet and tart cherry trees?

The primary difference in pruning sweet and tart cherry trees lies in their fruiting habit and growth. Sweet cherries fruit primarily on spurs, short lateral branches that produce fruit for several years, while tart cherries fruit mostly on new, one-year-old wood. Consequently, sweet cherry pruning focuses on maintaining an open structure for sunlight penetration and spur health, while tart cherry pruning emphasizes encouraging new growth for optimal fruit production.

Sweet cherry pruning aims to establish a strong central leader system or an open vase shape, allowing sunlight to reach all parts of the tree. This is achieved by removing vigorous upright growth that shades the interior, thinning out crowded branches to improve air circulation, and shortening overly long branches to encourage spur development. Older, less productive spurs may also be thinned out to promote the formation of new ones. Minimal pruning is generally preferred for mature sweet cherry trees, focusing only on removing dead, damaged, or diseased wood and maintaining the desired shape. Avoid heavy pruning, as it can stimulate excessive vegetative growth at the expense of fruit production. Tart cherry pruning, on the other hand, is more aggressive. Because they fruit on new wood, annual pruning is crucial to stimulate vigorous new growth each year. The goal is to remove older, less productive branches to allow sunlight to reach the younger branches where the majority of the fruit will be produced. This encourages the development of new fruiting wood. A modified central leader system or an open vase shape can be used, but it's essential to remove some of the older wood each year to maintain productivity. Heading back branches (cutting them to a bud) encourages branching and fruit production on the new growth.

How much of a mature cherry tree can I safely prune in one season?

As a general rule, you should aim to remove no more than 10-20% of a mature cherry tree's canopy in a single pruning season. Over-pruning can stress the tree, making it vulnerable to diseases and pests, and can negatively impact fruit production.

Pruning is essential for maintaining the health and productivity of cherry trees, but it's important to do it judiciously. Removing too much foliage at once shocks the tree. Cherry trees, especially sweet varieties, are already susceptible to diseases like Cytospora canker and bacterial canker, and excessive pruning wounds provide entry points for these pathogens. A moderate approach allows the tree to heal properly and redirect its energy into growth and fruit development. Consider prioritizing the removal of dead, damaged, or diseased branches first. These are not contributing to the tree's overall health and can be safely removed without significantly impacting the canopy. Beyond the general percentage, consider the tree's overall health and vigor. A healthy, vigorous tree can likely tolerate slightly more pruning than a stressed or weakened tree. Observe the tree closely for signs of disease or nutrient deficiencies before pruning. For older trees, it may take several seasons of careful pruning to restore them to a healthy and productive state. Focus on improving light penetration and air circulation within the canopy gradually, rather than attempting to reshape the entire tree in a single year.

How do I identify and remove dead, damaged, or diseased branches?

Carefully inspect your cherry tree during dormancy (late winter/early spring) for branches that are dead (brittle, lacking buds), damaged (broken, cracked), or diseased (exhibiting cankers, fungal growth, or unusual leaf patterns). Remove these branches using clean, sharp pruning tools, cutting back to healthy wood, a lateral branch, or the trunk, ensuring you make a clean cut just outside the branch collar to promote proper healing.

Identifying problem branches requires close observation. Dead branches are usually quite easy to spot, appearing gray or brown and brittle, often snapping easily. Damaged branches might show signs of physical injury, like cracks from wind or ice, or broken limbs. Diseased branches can be more challenging to identify. Look for telltale signs such as discolored or sunken areas on the bark (cankers), unusual growths or swellings, wilting or yellowing leaves on specific branches while the rest of the tree appears healthy, or the presence of fungal fruiting bodies. When removing any of these branches, the cut you make is critical. Avoid leaving stubs, which are prone to decay and insect infestation. Instead, locate the branch collar – the slightly swollen area where the branch meets the trunk or a larger branch. Make your cut just outside of this collar, angled slightly away from the main trunk or branch. This allows the tree to compartmentalize the wound effectively, sealing it off from disease and promoting rapid healing. For larger branches, consider using the three-cut method to prevent bark stripping: 1) undercut the branch a few inches from the collar, 2) make a second cut from above, a few inches further out, removing the bulk of the branch, and 3) finally, make the finishing cut just outside the branch collar. Remember to sanitize your pruning tools between cuts, especially when dealing with diseased branches, to prevent the spread of pathogens.

What type of cuts should I use when pruning cherry trees?

When pruning cherry trees, you'll primarily use two types of cuts: heading cuts and thinning cuts. Thinning cuts remove entire branches back to their point of origin, either a main branch or the trunk. Heading cuts shorten a branch or leader, stimulating growth near the cut.

Thinning cuts are generally favored for cherry trees as they encourage airflow and sunlight penetration throughout the canopy, which is vital for fruit production and disease prevention. These cuts reduce the density of the tree without stimulating excessive vegetative growth right at the cut, as heading cuts do. By removing entire branches that are crossing, rubbing, damaged, or diseased, you promote a healthier and more productive tree in the long run. Heading cuts, while less frequently used, can be helpful in specific situations. For example, you might use a heading cut to shorten a particularly long branch and encourage branching further back, thereby filling in gaps in the canopy. However, be mindful that excessive heading cuts can lead to a dense cluster of new growth ("witch's broom") that shades the interior of the tree and reduces fruit production. It’s important to make heading cuts to an outward-facing bud to direct the new growth away from the center of the tree. Therefore, prioritize thinning cuts, and use heading cuts sparingly and strategically to shape the tree and manage its growth habit.

How can I prevent diseases from entering the tree after pruning?

Preventing disease entry after pruning cherry trees primarily involves making clean cuts, pruning at the right time of year, and ensuring your tools are properly sterilized. This minimizes the wounds where pathogens can establish themselves.

Making clean, precise cuts is crucial. Avoid tearing the bark or leaving stubs, as ragged edges provide more surface area for disease to take hold. Use sharp pruning shears or saws, and always disinfect them before and after each cut, especially when moving between different trees or even different branches on the same tree. A simple solution of 1 part household bleach to 9 parts water, or rubbing alcohol, works well. Thoroughly clean the blades and allow them to air dry. The timing of pruning also plays a significant role. Pruning cherry trees during dry weather, ideally in late winter or early spring before bud break, allows the cuts to heal more quickly. Avoid pruning during wet or humid conditions, as moisture encourages fungal and bacterial growth. While debated, the application of pruning sealant is generally no longer recommended as it can trap moisture and create an environment conducive to disease; however, consult with a local arborist or agricultural extension for specific recommendations based on the prevalent diseases in your region. Focus instead on promoting rapid wound closure through good tree health and proper pruning techniques.

And that's all there is to it! Pruning cherry trees might seem a little daunting at first, but with a little practice (and maybe a few band-aids!), you'll be a pro in no time. Thanks for reading, and we hope this guide helps you grow the juiciest, most delicious cherries ever. Happy pruning, and please come back soon for more gardening tips and tricks!