Holly OakQuercus ilex
The holly oak is a tough evergreen tree as wide as it is tall with a dense rounded crown. It has smooth gray bark. The leaves are a leathery, glossy, dark green and vary in size and shape. The margins may or may not be irregularly toothed. Acorns are produced in the first year falling in autumn. Holly oak tolerates a wide variety of soil textures, salt, and drought, but is sensitive to cold. It requires regular watering until it is established and then should not be overwatered as this invites powdery mildew. Be sure to keep irrigation away from the base of the trunk as root rot can set in. It may require pruning when young to develop a strong branch structure. If left unpruned it can develop multiple leaders and take on a large shrub form. When given adequate soil space, it does well along streets and parking lots, and in parks and gardens in the western United States.