How to fix tree damage and angle of growth
Hi there, I have a crabapple tree in my backyard (not sure what kind) that is having a few problems. There is a large hole in the bottom section of the trunk (it's gotten much worse since last year, when I first bought the house. . . you know, the time that I SHOULD'VE dealt with it!). I wouldn't be quite as worried about it as a weak spot, except that the upper portion of the tree is growing at quite an extreme angle (I think some poor pruning was done at some point). The tree is healthy otherwise, looks beautiful in the summer and produces tons of really delicious crabapples. However, I'm worried that I'm going to end up losing the tree if I don't do anything. (Actually I'm worried the tree is too far gone. . . ) I'm wondering what I can do in terms of the hole in the trunk, if anything, and if I can somehow correct the angle that the top portion of the tree is growing at, without damaging it. Here are a couple of pictures:
Full picture of the tree from side with hole:
Closer picture of hole:
Closeup of damage in hole:
Full picture of tree from side opposite hole:
Closeup of tree opposite hole:
Certified GKH Gardening Expert
At this point in time, there is not much you can do about the angle of the tree. It looks like you have some rot going on in the hole, which is what is making it bigger.
You can treat the inside of the hole regularly with a fungicide and that can help reduce the rot. The tree itself is not in any danger from the rot, as the rot is occurring a layer of the tree that is dead. It is also a good idea to cover the hole to keep animals and further disease out, but make sure it is a removable flap so that you can continue a regular application of fungicide.
This is about the best you can do to maintain the structural integrity of the outside of the hole and trunk to keep it from getting worse. Some places will tell you to fill the hole, but do not do this. The rot will continue and the trunk will get weaker.