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.
Phytophthora cactorum
The best way to manage "P. cactorum" is by implementing an integrated management plan. The combination of soil fumigation and proper cultural controls will be the best option for plant health. Recommended chemical controls products include fosetyl-Al, metalaxyl, and etridiazole. Prevention and sanitation are crucial because this pathogen is usually transmitted through cuts or injuries on the plant. The spores are easily transported through irrigation water and will splash to nearby plants. Elevating your plants above the ground can help to prevent infection. The pathogen thrives in moist soils therefore it is important to avoid very saturated soils as much as possible and one should work to prepare their soil for adequate drainage during the wet periods. Soil drainage and low soil pH may help to reduce the disease. Fertilizer regimen methods have been used to control against "P. cactorum". These fertilizers include organic materials that release ammonia, nitrous acid, and amendments to reduce the pH to less than 4. The use of raised beds and a carefully managed drip irrigation system will be important cultural practices that can be implemented. There are some form of biological controls that have been found to be somewhat successful with "Enterobacter aerogenes" and "Trichoderma".