Phytophthora ramorum
Trials of silvicultural methods for treating "P. ramorum" began in Humboldt County in northwest coastal California in 2006. The trials have taken place on a variety of infested properties both private and public and have generally focused on varying levels and kinds of host removal. The largest () and most replicated trials have involved removal of tanoak and bay laurel by chainsaw throughout the infested stand, both with and without subsequent underburning designed to eliminate small seedlings and infested leaf litter. Other treatments included host removal in a modified “shaded fuelbreak” design in which all bay laurel is removed, but not all tanoaks; bay and tanoak removal using herbicides; and removal of bay laurel alone. The results of these treatments are still being monitored, but repeated sampling has so far detected only very small amounts of "P. ramorum" in the soil or on vegetation in the treated sites.
Rosellinia bunodes
Despite best management practices, black root rot can still occur necessitating human intervention.  Root pruning and digging various styles of trenches to eliminate root contacts is one way of preventing disease spread. This approach is labor-intensive and may only be feasible for small-scale growers or for very localized outbreaks. Fungicide treatments usually include broad-spectrum approaches such as metam sodium, benzimidazoles, chlorophenyls, imidazole, morpholine, oxathiin, triazoles, and some inorganic compounds. Some research has shown biocontrols using mycorrhizal or mycoparasitic fungi (i.e.: "Trichoderma" spp., "Clonostachys" spp., "Glomus manihotis", and "Entrophospora colombiana") to be effective in suppressing the disease, but it is not clear if these interventions are successful only in certain environments or in specific host-pathogen combinations. Biocontrol interventions, however, are most effective when used in conjunction with cultural practices like canopy pruning and liming soil to raise pH. Crop rotation or including non-host species as part of planting schemes can also restrict the spread of the pathogen. Soil solarization has also shown to eliminate up to 75% of inoculum for closely related "Rosellinia" spp., but has not been evaluated with "R. bunodes".