I know that pear trees are a bit different, but just as an example of how bad a fruit tree can get, yet still be useful, I offer the following.
When we bought our property, there was an old pear tree by one of the old homesteads, now long gone. Best we can determine, it is a "Winter Nellis" variety. It had not been tended at all in at least several decades. The trunk was encircled by a poison ivy vine about 5 inches in diameter that had nearly killed the tree. Major portions of the main trunk were completely rotted.
We cut off the poison ivy and severely pruned much of the wildly overgrown top out the tree, probably 40% of its overall growth, then fertilized it well with ground spikes. The following year, it rewarded us with beautiful blossoms, new growth and a bumper crop of pears. We found it very hard to believe that it could do so well and that the weight of the crop did not break the severely damaged trunk. It has continued to do well since, but is still a challenge to keep vertical growth in control.


- Jay
When we bought our property, there was an old pear tree by one of the old homesteads, now long gone. Best we can determine, it is a "Winter Nellis" variety. It had not been tended at all in at least several decades. The trunk was encircled by a poison ivy vine about 5 inches in diameter that had nearly killed the tree. Major portions of the main trunk were completely rotted.
We cut off the poison ivy and severely pruned much of the wildly overgrown top out the tree, probably 40% of its overall growth, then fertilized it well with ground spikes. The following year, it rewarded us with beautiful blossoms, new growth and a bumper crop of pears. We found it very hard to believe that it could do so well and that the weight of the crop did not break the severely damaged trunk. It has continued to do well since, but is still a challenge to keep vertical growth in control.


- Jay