Root grafting is a normal process and like the article suggest, it can be problematic for the trees. In Texas and others states affected by oak wilt one of the

Root grafting is a normal process and like the article suggest, it can be problematic for the trees. In Texas and others states affected by oak wilt one of the main defenses against it is to trench between healthy and sick stands of oaks. This can be extremely expensive especially in the hill country where trenching involves using a rock saw to cut through the surface limestone. Oak wilt is a fungal disease that is spread through the root systems of interconnected trees and by actions of a specific beetle that is most active between end of February and late July. TAMU recommends no pruning of anything larger than a pencil between those dates if I remember correctly. I had the misfortune of learning about this affliction after buying a home in north Texas that had mature live oaks, some more than a hundred years old, and watching those live oaks die suddenly. Live oaks are evergreen and when they suddenly started browning the second spring after buying the property I had already lost more than 10 trees. Once it began affecting the 3 signature trees out front I called in an arborist and had many of them treated with a chemical fungicide. That was expensive. I also rented a backhoe and trenched between the sick and healthy stands on my place and between my property and my neighbor's. He had some beautiful oaks on his place too and I didn't want his trees to go down simply because they were root grafted across the fence to mine. The end result is that I lost more than a dozen mature live oaks and the three trees out front that were treated once they started showing signs of oak wilt are still alive, albeit with greatly reduced canopy. The fungus usually kills 95% of the trees it afflicts and if the tree survives it never has a full canopy. It can take a full year for the fungus to kill a mature live oak due to the small size of the pores which transport nutrients from leaves to roots and vice versa. A mature red oak on the other hand can be killed in a week since the pore sizes are much larger. I lost a perfect specimen tree that survived the initial affliction more than 15 years prior. It suddenly died four or five years ago. Many other red oaks in the area are dying too. I rambled a bit there but overall an informative article that brought back unpleasant memories of my own battle with and experience with root grafted trees and some of the problems you may face.