Your holly bushes are losing leaves is because of not enough sun?

Hollies will shed interior leaves seasonally - usually in the fall of the year. People have a misconception that confiers (evergreens) do not lose their leaves. As we see, pines and spruces shed their older needles each year - pine straw mulch would not exist otherwise. Hollies do the same. You can tell it is a natural sheding of leave when it is the older, interior leaves, while the new outer growth remains intact. Concerns will arise when the new growth is shed, or when a heavier than normal loss of older leaves occurs. This may occur due to biotic or abiotic stresses to the tree from the current or prior growing seasons (drought, late or early frost, etc). Irrigations and fertilization, when needed, will help your holly continue to add beaty and interest to your landscape.