Broadleaf and needled evergreens (such as white pines and spruces) normally shed their older leaves. Depending on the species of plant, normal needle or leaf drop can be seen at various times of the year — spring, fall, and even late winter.
- Older leaf shed occurs in the fall on pines and azaleas and in the spring on magnolias and hollies.
- Initially, there is a color change on the interior leaves, from green to yellow, red, or brown. This process can occur over several days to several weeks.
- Next, these leaves will drop over a period of a few days to a few weeks.
- Leaves live for a period of one to four years; this type of normal leaf drop can occur every year, every second year, or every third year.
- When there is a large amount of new growth during one season, the discoloration and drop of these leaves can be quite dramatic. Yet, there is no harm to the plant. During years of stress, such as drought, excessive heat, insect or disease damage, the change in color and leaf drop can occur over a short period of time.
- This second-year needle yellowing occurs towards the interior of the tree. It may occur all at once and it could be quite dramatic.
- This needle yellowing is a normal fall color and precedes needle drop.
- After needles drop in the fall, trees should appear healthy.