See:
Rhododendron - Ramorum Leaf Blight and Shoot Dieback
Tanoak (Notholithocarpus densiflorus) - Sudden Oak Death
Note Infected Douglas-fir and grand fir have been reported from California in situations where they are growing in close proximity to other hosts that produce high levels of inoculum. In Oregon, a few Douglas-fir seedlings (and a few Grand Firs) growing directly beneath infected overstory tanoaks in Curry County have been found infected. Both the NA1 and EU1 clonal linages have been found on firs. The disease has not been found in any Christmas tree plantations. Douglas-fir appears to be susceptible for a limited period of time just after bud break.
Symptoms Symptoms associated with Phytophthora ramorum infections include needle blight, a shoot blight resulting from needle infections, and stem lesions resulting from the growth of the pathogen from infected newly emerging needles/shoots into older wood. Symptoms are similar to Botrytis shoot blight on young seedlings. Douglas-fir and grand fir are on the hosts and associated hosts lists, respectively.
References Goheen, E. M., Hansen, E., Kanaskie, A., Osterbauer, N., Parke, J., Pscheidt, J., and Chastagner, G. 2006. Sudden oak death and Phytophthora ramorum: a guide for forest managers, Christmas tree growers, and forest-tree nursery operators in Oregon and Washington EM 8877. Corvallis, OR: Oregon State University.
LeBoldus, J.M., Sondreli, K.L., Sutton, W., Reeser, P., Navarro, S., Kanaskie, A., and Grünwald, N.J. 2018. First report of Phytophthora ramorum Lineage EU1 infecting Douglas Fir and Grand Fir in Oregon. Plant Disease 102:455.