Tanoak is among the several species in northern and central California that have been affected by the Phytophthora fungus, in what is called “sudden oak death syndrome.” The disease is easily spread by beetles attracted to the sap of the infected trees. Contact with infected roots and wood, and infected soil may be transported on tools, tires or shoes (Brenzel 2001). To keep trees healthy, apply a thick layer of mulch to the root zone area beneath the crown and do not garden or disturb this area in any way. Also avoid frequent irrigation, prune only from June to September (when the fungus and insects are less active), and fertilize if the tree shows signs of deficiency (Švihra et al. 2001). Prunings and firewood from infected trees should be enclosed in heavy, clear plastic for 6 months in order to trap and kill beetles that may emerge and infect nearby living trees (Brenzel 2001). Other pests include aphids, greedy scale, mealybug, oak scale and white fly.