Mushroom Root Rot
Mushroom Root Rot is a common disease of many trees and shrubs caused by the fungus Armillaria spp. This fungus spreads through root-to-root contact of infected and healthy plants, as well as through airborne spores. The disease causes decline and eventually death of infected plants. There is no effective preventive or curative fungicide treatment for this disease.
Plants that are susceptible to Mushroom Root Rot disease include most trees, shrubs, and many groundcovers. Infected plants often do not show decline symptoms for months to years following infection. At some point the infected plant “gives up”, resulting in what appears as sudden decline or death of a portion or the entire plant.
The easiest way to identify Mushroom Root Rot is by its distinctive mushrooms. Short-lived Yellow to brown mushrooms that grow in clusters in close proximity to trees or shrubs are likely those of the Armillaria spp. pathogen. The mere presence of the mushrooms, however, does not necessarily indicate infection. Likewise, the lack of mushrooms does not exclude the possibility of disease. Infection can be confirmed by observation of the fungus (white mycelia) under the bark of a diseased plant.
Plants that are susceptible to Mushroom Root Rot disease include most trees, shrubs, and many groundcovers. Infected plants often do not show decline symptoms for months to years following infection. At some point the infected plant “gives up”, resulting in what appears as sudden decline or death of a portion or the entire plant.
The easiest way to identify Mushroom Root Rot is by its distinctive mushrooms. Short-lived Yellow to brown mushrooms that grow in clusters in close proximity to trees or shrubs are likely those of the Armillaria spp. pathogen. The mere presence of the mushrooms, however, does not necessarily indicate infection. Likewise, the lack of mushrooms does not exclude the possibility of disease. Infection can be confirmed by observation of the fungus (white mycelia) under the bark of a diseased plant.
Plants that are commonly infected by Mushroom Root Rot in landscapes include Azalea, Podocarpus, Indian Hawthorn, Ligustrum, Anise, Holly, and many more. It is not uncommon for only one plant in a hedge to die due to the disease.
If you have a plant that is declining or has died due to Mushroom Root Rot, it is important to remove it and as much of the root mass promptly. It is best to replace dead plants with different plants that have documented resistance to the disease. If that is not possible (as in the case of a single plant that has died in a hedge), then removal of as much soil as possible and replacement with new soil prior to replanting with the same plant is recommended.
Please follow the link below for additional information about Mushroom Root Rot and a list of resistant species. Please note that resistance does not imply immunity, and although unlikely, a listed resistant plant may still become infected.
Mushroom Root Rot - additional information
If you have a plant that is declining or has died due to Mushroom Root Rot, it is important to remove it and as much of the root mass promptly. It is best to replace dead plants with different plants that have documented resistance to the disease. If that is not possible (as in the case of a single plant that has died in a hedge), then removal of as much soil as possible and replacement with new soil prior to replanting with the same plant is recommended.
Please follow the link below for additional information about Mushroom Root Rot and a list of resistant species. Please note that resistance does not imply immunity, and although unlikely, a listed resistant plant may still become infected.
Mushroom Root Rot - additional information