Pruning a cherry tree improves fruit production, manages size, and maintains long-term health. It allows greater sunlight penetration throughout the canopy, enhancing the sugar content and quality of the fruit. Increased air circulation reduces the incidence of fungal diseases that thrive in damp environments. Proper cuts control the tree’s shape, ensuring the structure supports heavy crop loads and keeps the fruit within manageable harvesting height.
Setting the Stage: Timing and Equipment
The timing for pruning cherry trees prevents disease and manages tree vigor. For sweet cherries (Prunus avium), major structural pruning is preferred in late summer immediately following harvest, typically July or August. Pruning during this warmer, drier period minimizes the risk of infection by fungal pathogens like Silver Leaf Disease, which can enter through fresh wounds during the cooler, wet dormant season. Tart cherries (Prunus cerasus) are often pruned in late winter or early spring just before the buds swell, which stimulates more vegetative growth.
Light summer pruning can be performed on both varieties for size control, but heavier cuts should be reserved for the post-harvest period for sweet cherries. Regardless of the season, all pruning cuts should be made when a 48-hour period of dry weather is expected. This allows the wound surface to begin sealing effectively.
A successful pruning session requires sharp, clean tools to ensure precise cuts that heal quickly. Hand pruners are used for small shoots up to about an inch in diameter. Loppers provide leverage for branches between one and two inches thick. For larger limbs, a curved pruning saw allows for clean removal without tearing the bark.
Structural Training for New Trees
The first three to five years of a cherry tree’s life are dedicated to formative pruning, which establishes the tree’s permanent framework. For sweet cherries, the modified central leader system is often employed, where a single dominant trunk is maintained. The goal is to select and space scaffold branches that will form the primary load-bearing structure of the mature tree. These scaffolds should be distributed radially around the trunk and vertically separated by about eight inches to ensure good light penetration to all tiers.
The first cut on a newly planted whip often involves a heading cut on the leader, shortening the main trunk to a specific height. This stimulates the growth of multiple side shoots and helps establish the desired branch structure early. Branches that grow with a tight, narrow V-crotch angle should be removed, as these are structurally weak and prone to splitting under a heavy fruit load.
Any growth appearing below the graft union, known as a sucker, must be removed immediately to prevent the rootstock from dominating the scion. Lateral branches should be encouraged to grow at an angle between 45 and 60 degrees from the leader, which is achieved by using spreaders or weights during the first summer. This structural training guides the tree’s energy into developing a strong, open pyramid shape that maximizes the amount of light reaching the lower canopy.
Ongoing Maintenance for Mature Trees
Once the primary scaffold structure is established, annual maintenance pruning focuses on renewing fruiting wood and maintaining the tree’s open architecture. Thinning cuts are the preferred method, involving the complete removal of a branch back to the trunk, a larger limb, or the branch collar. These cuts open the canopy, remove dead or damaged wood, and eliminate crossing or downward-growing branches. Removing entire branches stimulates less vigorous regrowth than shortening cuts, helping maintain the tree’s size and shape.
Water sprouts (vigorous, vertical shoots) and suckers emerging from the base of the tree should be removed completely. Leaving these sprouts diverts energy away from fruit production and crowds the tree’s interior. Proper pruning involves making a clean cut just outside the branch collar. This slightly swollen area at the base of the branch contains specialized cells that facilitate the tree’s natural wound sealing process, allowing the cut to close over quickly.
Heading cuts, which involve shortening a branch back to a bud, are less frequently used on mature trees but can be applied to regulate fruit load. By shortening one-year-old wood, a portion of the flower buds are removed, which can result in fewer, but larger, individual fruits. Over-pruning with heading cuts, however, can stimulate excessive vegetative growth at the expense of fruit production, disrupting the balance between wood growth and fruit-bearing.
Variety Specific Pruning: Sweet vs. Tart
The fundamental difference in pruning sweet and tart cherry trees is dictated by their distinct fruiting habits. Sweet cherries (Prunus avium) primarily produce fruit on long-lived structures called spurs, which bear fruit for multiple years. Consequently, sweet cherry pruning focuses on establishing a strong, permanent scaffold structure, often using a central leader system, and protecting these spurs. Pruning involves thinning out older, less productive wood while preserving the main limbs that support the permanent spur system.
Tart cherries (Prunus cerasus), such as the popular Montmorency cultivar, predominantly produce fruit on one-year-old wood, specifically on the lateral buds along the previous season’s growth. This difference means tart cherry trees require a heavier annual renewal pruning to stimulate the continuous production of new fruiting wood. They are generally trained to a more open vase or modified leader shape, which encourages a bushier habit and facilitates light penetration to the inner canopy.
The heavier annual pruning for tart cherries involves removing about one-quarter of the older wood each year. This forces new, one-year-old shoots that will bear fruit the following season. This renewal system prevents the tree from becoming leggy and unproductive.