There is usually little physiological injury. Damage is primarily cosmetic. In forest trees, it has been found that the increment of trunk growth is reduced by about the same proportion as the degree of defoliation experienced of the crown. B. Cosmetic injury is important, however, when plants are grown for sale or are located in critical landscape applications 1. specialty landscapes, ie. Evergreens are more susceptible to injury.
Leaves are slower to mature and reach full photosynthetic productivity.
They may take up to two years to reach peak performance while deciduous plants may take only one to two months. Much more of the carbohydrate storage is in the leaves and is therefore lost with them. Repetitive defoliation can take damage even deciduous trees and shrubs 3. Loss of leaves in late spring to early summer for any reason is more significant than either early spring or late summer. In fact, the later in the season the defoliation occurs, the greater the degree of defoliation required to trigger refoliation.