Phytophthora: Sudden Oak Death

Phytophthora ramorum

This is the invasive plant pathogen that causes sudden oak death. It was discovered in California in the 90s and has killed millions of oak trees on the coast. It infects the trunk of mature, established oak trees and causes bloody looking cankers to appear.

What can be done?

Unfortunately there is no cure as of yet for sudden oak death but there are ways to manage the disease. We offer a treatment where we spray the bark of the tree with phosphate mixture which is a natural fungicide. The spray acts as an immune boost for the tree to help it fight off the disease for longer. We usually do this spray in the fall to help prime the tree before rainy season, which is when the disease commonly spreads. For certain cases we can do a second treatment right after the rains have ended in the spring to help better protect the tree.