Certified Arborist Practice Exam

Trees that "bleed," such as maples, often exhibit sap flow or wound exudation when pruned during certain times of the year. This phenomenon typically occurs in late winter or early spring when trees are preparing to leaf out and sap flow increases. Pruning during this period can lead to excessive sap loss, which may stress the tree and lead to a decline in vigor.

The rationale behind avoiding spring pruning for these species is based on the physiological responses of the tree. When trees bleed sap, it can result in not only the loss of essential nutrients but also create openings for pathogens and pests, further compromising the tree's health.

Therefore, the statement that trees that tend to "bleed" should never be pruned in early spring to prevent a major decline in vigor is accurate. This highlights the importance of understanding the specific needs and responses of different tree species when planning maintenance activities.