I'm not a professional arborist, but I'd let the tree try to heal itself. A photo of the damage might help to give a better opinion. Squirrels, rabbits and other animals can do quite a bit of damage to plants in containers or in gardens. I've had several small trees (seedlings mostly) growing in containers that have been knocked over by squirrels, usually causing the tree roots to dessicate and die, so they can be a nuisance indeed. When I used to use fish emulsion as a suppliment I had this happen on a regular basis! It's just part of gardening I guess. You might put some plastic bird netting around your plants if the damage continues. I've heard this can be an effective deterrent for small animals. HTH Dave

Hard to say from the unknown size of the tree how much 1.5" is but going by my 3 year old trees I would say it will be fine on its own. I think even my 3 year old dwarf tree could deal with 1.5". But that would be enough to plan on replacing my 2 year old dwarf grafts. My roommate is good about weed eating trees to death. It's only a whack here and there (except for the new tree that he debarked clear around once), but a little bit every week for 6 months adds up. It took a lot of yelling to get him to stop weed eating the trees at all.

Not shipping damage? what are you talking about? Even the seller agreed those trees were damaged during shipping. What I am talking about is the fact that the second photo shows mending tissue in the split. It didn't begin to heal in transit. I do not understand why some people make some strong statements about something they do not even know... Interesting.... What I find "interesting" is the fact that you say you took pictures to show the damage in your post and chose to upload photos of the "two best trees" for example. What do you expect...viewers to infer that other trees must have been damaged more badly? If they agreed to replace them. then good for you. I agree the shipping method sounds a bit iffy and there "IS" an issue with damage regardless of how it happened.

Whenever I see frass tubes like this, I think of Ambrosia beetles. These little guys are a real problem on a wide variety of hardwoods, including cherries and other fruit trees. At this point, the beetles (if this is what it is) have infested the heartwood of your tree and have likely carried along a fungus or two with them just for good measure. Unfortunately, there is NOTHING that can be done once a borer like this has done its work. It's not all bad news, though. Healthy, established trees can live for quite some time after an attack, in some instances. Be sure that your tree is well mulched over a generous area. Most people are stingy with the mulch rings around their trees. A three or so inch layer of organic mulch is the best thing you can do for the root system of your tree. As a matter of fact, one of the best tactics of prevention is to do all that you can do to maintain your trees in tip-top health. Mulch is an important factor in that effort. Trees can also very suddenly die. It's amazing that a tiny little beetle can take down trees, isn't it?