The accompanying photos show canker on my "Waterfall" Japanese maple tree, which I planted three years ago this spring. Our local county extension agent told me the tree will die from the condition, no question, and I should go ahead and remove it. I'm wondering, first, if his assessment is correct, and if so is it contagious to plants in its vicinity and should I take any steps to decontaminate the soil in which it is planted? (I should add that this is one of three infected Japanese maples I purchased from the same nursery, and I returned the other two for a refund. The Waterfall apparently was slower than the other two in displaying symptoms. BTW, I no longer patronize the nursery.) About the photos: the middle is a top-down view of the infection on the trunk at the junction of the upper set of branches on the tree; the left is a skewed vertical -- the right side should be the top of the photo --showing a side view of the same section; the right is an overview of the tree. You may not be able to tell by looking at the photos because I took them after leaf fall, but one-half of the tree -- the lower set of branches -- is thriving and shows no sign of disease; the other half -- the upper set of branches -- had been vigorous but now is showing obvious signs of disease. This leads me to ask, if canker is not always fatal, could I prune the upper set of branches below the point on the trunk where the canker is visible and see how the amputated tree does? (It's not that I hesitate to return the tree; it's just that if it can be rescued I want to try.) All observations and suggestions will be appreciated. Thanks.
What, specifically, do they think has infested the shrub? "Canker(s)" in this context is almost like "warts" or "cuts" - it does not refer to a particular agent, unless used in a combination like "bacterial canker". Even in that case there can be some room for variability, when the scientific name of the bacterium involved is not given.
Thanks for your response! He was non-specific. He simply used the term "canker." Whatever it is, it manifests itself with the bark peeling off, exposing what I am assuming is the cambium layer, which appears to be completely dry -- dead? -- tissue. Around the wound, a ridge has built up, separating what appears to be healthy (bark) tissue from the infected tissue. The wound appears to be growing upward on the trunk, toward the system of branches the form the top of the tree. I should admit my limitations -- I am neither a horticulturalist nor an arborist, just an avid weekend gardener trying to inform myself as I encounter issues that affect my garden!
If the offer of a refund is still available I would take it. If you were to amputate half of the plant, the part that is left would look lop-sided and awkward whether it is healthy or not, and in a best-case scenario would take years to return to a balanced structure. Your county extension agent has already outlined the worst case scenario.
