Port Offord Root

Asked February 18, 2013, 1:07 AM EST

I have a stand of Port Offords Cedars that have contracted fungus Phytophthora lateralis. It has killed atleast 15 trees. I have culled the infected trees out, only to notice there are more trees that are infected and in different stages of dying. There are still a few trees in the stand of cedars that have not been infected. However, it seems the fungus is moving its way down the stand of trees. Is it a matter of time until all the trees in the stand become infected? Would I be best to cut down all trees in order to contain the fungus. There is about a 15 foot break from one stand to the next stand of cedars and I would like to try and contain the fungus. Any suggestion would be great. It is my feelings that I should cut all the trees in close proximany of an infected tree in order to try to contain it. I would consider close proximany to be 10 feet. Thanks

Clackamas County Oregon plant disease forestry horticulture

1 Response

Once you have Phytophpthora lateralis in a grove of Port Orford cedar, it is very likely that "it is just a matter of time" before all trees get the disease and die. It is also most likely the group of trees 15 feet away will get it soon. The fungus spreads through both soil water, soil particles with spores, and spores directly. So with the fungus that close, it is very likely to infect them. I would plan for removal of dead trees and think about suitable replacement trees for the soil and site conditions. P. lateralis does not infect species outside of the genus Chamaecyparis.