A common question among Treasure Valley homeowners is, “When is the right time to prune my trees?” While dead or hazardous branches should be removed immediately regardless of the season, structural pruning of deciduous trees should be reserved for late winter, while the tree is still in deep dormancy. Pruning when the canopy is bare allows an arborist to see the architecture of the tree clearly, identifying crossing branches and weak unions. More importantly, winter pruning aligns with the biological process known as CODIT (Compartmentalization of Decay in Trees). When a cut is made just outside the branch collar, the tree reacts by sealing off the wound with specialized chemical and physical barriers. Pruning in late winter ensures that as soon as sap begins to flow in the spring, the tree actively directs its energy into rapid wound closure before airborne fungal spores become active. Conversely, pruning during the spring bud-break or the heat of late summer depletes the tree’s energy reserves and leaves open wounds highly susceptible to pests and disease.