Bacterial Canker on cherry tree
Hello, we have a mature cherry tree that has Bacterial Canker and is oozing amber liquid and also has some shot hole fungus (but not too badly). We are renovating the backyard where the tree stands to install a patio and our designer wants us to decide whether to remove the tree. If we remove it, we'll have more patio space but we like it and it provides nice shade. Our question is whether it will survive the renovation as we understand it has shallow roots and what its chances of longevity are given the canker. Are you able to advise on its lifespan and recommend how we should move forward on this? Many thanks!
Multnomah County Oregon
There are a number of questions that would help me to help you that I don't have answers too such as how old is the tree, how deep will you be digging and how close to the construction is the tree, how sick is the tree and where is the infection located on the tree? Lacking the answer to those questions it is difficult to know how to advise you.
Once cherry trees become 8-10 years old they become more resistant to bacterial canker, however, there is another disease, caused by a fungus called Cytospora canker that causes the same symptoms and attacks older trees. Little can be done for either disease, except pruning out the infected plant part. If the infection is on the main trunk and the tree has been dying back for a number of years I would remove it and start with another tree in a better location in relation to the new patio. If the infection is on a side branch you could try to remove the side branch, which might or might not protect the tree from further infection. If you remove a branch or two, is the tree still balanced?
Most trees can survive 20% of their roots being cut. The majority of feeder roots in a cherry tree will be located near the surface, just under any lawn, but structural roots will be deeper and cutting these roots can not only damage the tree but could cause the tree to become unstable during a storm.
Finally, I think that you need to think about what will happen to the fruit of the tree if you leave it in. If you control cherry fruit fly with pesticides, do you want the pesticides to drift onto your patio, furniture and BBQ? If you don't spray the fruit what will happen to the infested cherries? Will they just drop on the lawn or the patio and are you okay with that?