Large oaks are usually hollow or rotten in the center, making exact age determinations impossible. Valley oaks have a highly branched growth habit.
Valley oak is wind pollinated.
The age of sexual maturity and maximum acorn production are not recorded in the literature. There is no dormancy requirement. Seed-caching animals which bury acorns, such as scrub jay and California ground squirrel, are important to species survival. Some acorns, however, remained until spring when black-tailed deer and cattle were excluded from the area. Germination is hypogeal.