Pruning is a necessary maintenance task for cherry trees, helping to maximize fruit production, manage the tree’s overall size, and maintain its health. The timing of pruning is a highly important factor, as cherry trees are susceptible to diseases that can enter through fresh cuts. Understanding the specific goals for each pruning window—dormancy for structure and summer for health—will ensure the tree remains vigorous and productive. Cherry trees, particularly sweet varieties, require a specialized schedule to mitigate the risk of fungal infection.
Structural Pruning During Dormancy
The primary time for major structural renewal and size management is late winter, just before the buds begin to swell and the tree breaks dormancy. This window typically falls in late February or early March, depending on the local climate. Pruning heavy cuts during this period is preferred because the tree’s energy is stored in its roots and trunk, allowing it to better handle the loss of wood. The wound healing process begins quickly as spring growth starts, and the risk of infectious spores is lower than in early winter.
Dormant pruning stimulates vigorous new growth, helping renew fruiting wood and maintain structure. Sweet cherry varieties benefit from lighter pruning, as they bear most of their fruit on older wood known as spurs. In contrast, tart cherries, which primarily fruit on one-year-old wood, can tolerate heavier pruning to encourage new shoots. The goal of dormant pruning is to establish a strong central leader or open structure and remove large branches that crowd the canopy.
Post-Harvest Health Pruning
A secondary pruning window occurs in mid-summer, immediately after the cherry harvest, typically spanning July or August. This timing is adopted for health management and disease prevention, especially for sweet cherries. Pruning during the warmer, drier conditions of summer allows the tree to quickly seal its wounds, significantly reducing the opportunity for fungal pathogens to gain entry. This practice is a direct strategy against Silver Leaf Disease, caused by the fungus Chondrostereum purpureum.
The airborne spores of Chondrostereum purpureum are most active during the cool, wet weather of autumn and winter, which increases the risk of systemic infection if cuts are made then. Summer pruning focuses on removing dead, damaged, or crossing branches that restrict air circulation, rather than on major structural cuts. This lighter removal of wood improves the health of the tree.
Timing Considerations for Young Cherry Trees
The initial few years after planting, generally the first three to five seasons, require a focused approach aimed at training the tree’s permanent structure. The timing for these formative cuts often aligns with the late-winter dormant period, but the goal is establishing a long-term framework. The objective is to select and develop the main scaffold branches that will support future heavy fruit loads, often following a modified central leader or open center system. This early training sets the stage for the tree’s eventual height and spread, simplifying future maintenance and harvesting.
A significant action in the first year is the heading cut, where the central leader is cut back to encourage lower lateral branching and control height. Selecting appropriate scaffold branches involves choosing limbs with wide crotch angles that are well-spaced around the trunk, ensuring a strong, balanced structure. Subsequent years involve promoting outward growth and maintaining the dominance of the central leader by removing competing vertical shoots.