When should old, established trees be pruned?

When should old, established trees be pruned?

• A. Any time
• B. Winter or early spring
• C. Summer
• D. Fall after leaf drop

Answer: (B)

Pruning old trees is best during dormancy, in winter or very early spring, because the tree is not actively growing and sap flow is low. This makes cuts less stressful for the tree, reduces the chance of disease and pest problems entering through fresh wounds, and lets you clearly see the branch structure to make accurate, deliberate cuts. As growth resumes in spring, the tree can rapidly seal those wounds with new tissue. Pruning in other seasons tends to cause more problems: summer pruning often prompts unwanted, vigorous regrowth and can lead to sunscald on the new wood; fall pruning can stimulate new growth that won’t have time to harden before winter, increasing damage risk; pruning during active growth also disrupts carbohydrate reserves and can make the tree more vulnerable overall.

Pruning old trees is best during dormancy, in winter or very early spring, because the tree is not actively growing and sap flow is low. This makes cuts less stressful for the tree, reduces the chance of disease and pest problems entering through fresh wounds, and lets you clearly see the branch structure to make accurate, deliberate cuts. As growth resumes in spring, the tree can rapidly seal those wounds with new tissue.

Pruning in other seasons tends to cause more problems: summer pruning often prompts unwanted, vigorous regrowth and can lead to sunscald on the new wood; fall pruning can stimulate new growth that won’t have time to harden before winter, increasing damage risk; pruning during active growth also disrupts carbohydrate reserves and can make the tree more vulnerable overall.