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 erythroseptica
A multi-faceted approach is recommended to control pink rot. Sanitation of fields to reduce the amount of residues and volunteer potatoes is important to remove sources of inoculum or places the pathogen can overwinter. A crop rotation of 3–4 years is recommended to limit the amount of surviving spores in the soil, which is the main form of inoculum. Most cultivars of potatoes currently in production are susceptible to pink rot; however, some are more resistant than others. Varieties that are particularly susceptible are Dark Red Norland, Red LaSoda, Russet Norkotah, and Snowden.