Jasmine from Ambler,pa writes
Big beech tree has a green and black mold on bark. Tree guy said it is canker. I can’t spray it because it is too tall and big. It is so difficult to find about beech tree canker treatment.
Monterey Garden Phos Systemic Fungicide is labeled for Pine Pitch Canker on ornamental trees caused by Fusarium sublutinans. You would apply Garden Phos as a basal bark spray from the ground level up to 5 feet above the soil line. The manufacturer recommends applying this with PentraBark surfactant. Some canker diseases are not treatable using fungicides. You can read more about beech disease in this article from Penn State Extension. We recommend consulting with an arborist or Master Gardener through your local Extension office if you still need assistance identifying the issue with your tree.
Answer last updated on: 06/21/2018