[2] It can reproduce vegetatively with new growth sprouting from the root crown after the tree is top-killed by wildfire, logging, frost, or other events.

[3] In open areas, the crown is broad and rounded, with lower branches nearly touching the ground or forming a browse line.

[3][4] The leaves are typically 10–25 centimeters (4–10 in) long and deeply lobed, usually into seven portions; they are red and velvety when young, turning yellow-green then orange-brown in autumn.

[4] Blooming late in spring, the species is monoecious, with male flowers in catkins and females in leaf axils.

Pure stands usually indicate sites unfavorable to conifer growth or recurring disturbance such as fire or logging activities.

[9] Acorns are heavily used by livestock, mule deer, feral pigs, rodents, mountain quail, Steller's jays, and woodpeckers.

Acorns constitute an average of 50% of the fall and winter diets of western gray squirrels and black-tailed deer during good mast years.

Acorn woodpecker, Bullock's oriole, and Nashville warbler show strong preferences for California black oak.

The parasitic plant Pacific mistletoe (Phoradendron villosum), which commonly grows on this oak, produces berries that attract birds, as well.

If it is top-killed and burned away in a larger fire, it easily resprouts and has a good supply of nutrients and water stored in its root system.

This is due to a number of factors, including drought, disease, animal foraging, logging practices, fire suppression, and a variety of other human impacts.

In its earlier years, its only use to settlers was to feed the boilers of donkey engines bringing in the valuable pine and fir logs.

Like a few other visionaries in the 1960s, Guy Hall thought the California black oak presented a beautiful challenge that deserved better than eradication.

Q. kelloggii is cultivated in the specialty horticulture trade as an ornamental tree for native plant, drought-tolerant, water-conserving, and habitat gardens, and various types of municipal, commercial, and agency sustainable landscape and restoration projects.