I’m considering removal of bay with ramorum blight, but I have symptomatic and asymptomatic tanoak on my property. Will bay elimination protect my oaks and tanoaks?

Both bay laurels and tanoaks can spread SOD while most oaks are not infectious.  Therefore, bay removal is typically aimed at protecting oaks. In the absence of bays, you may actually be able to facilitate survival of asymptomatic tanoaks, but only if their density is low (about 20 per acre).  A possible plan of action may thus be to eliminate all medium-sized bay trees (up to 20 inch DBH) that are not in a riparian setting and to eliminate all infected tanoaks. You may then decide to leave a few well-spaced tanoaks (50 feet minimum from one another), ensuring none of them are within 30 feet of an oak.

After taking down a P. ramorum-infested bay tree, can the foliage be left onsite to decompose?

Once down, spores from bay foliage will not travel nearly as far as they do in the canopy. The concern on the ground is that infested leaves, while still fresh, could have spores picked up during a wet event from soil splash onto the trunk of the tree. So, spread bay foliage in a thin layer in a sunny area that will promote drying. Be sure to not have foliage near the base of oak or tanoak trunks where soil splash/infection could occur.

When should I remove a tree?

Tree removal is most likely required if the tree is a hazard to property, people, or places where people congregate (paths, camp grounds, etc.) Bear in mind that individual limbs may be more of a hazard than the failure of the entire tree. A certified arborist should be consulted to determine whether tree removal is needed. Proper pruning, fertilizing, and watering of ornamental trees may improve the overall health of your trees and reduce the likelihood of removal.