Since the foliage of an evergreen can live from one to several years, the amount of shedding will vary among the different evergreens. In most cases the foliage will first turn yellow, then straw colored and eventually brown, at which time it drops to the ground. Although striking in appearance, this is a normal process of aging. Pine trees produce needles in sets of 2 to 5 per fascicle or bunch. Individual bunches of needles will change color and drop off.
Pines shed their oldest needles in autumn.
Most pines retain needles for 3 to 5 years. An exception is the white pine that retains its needles for only 1 year. These leaves will drop individually sometimes over an extended period of time. Hemlock and yew can retain needles for 3 to 5 years. The spruces and firs also produce single needles on twigs.