It's only in September 2024 that Callery pear was black-listed in Massachusetts; however, the grace period, during which nurseries can still sell their inventory, was prolonged until 2028. Nowadays, Callery pear is also commonly used as rootstock for grafting other cultivated pears. Whenever the grafted scion dies (which happens rather often), the rootstock takes over and the tree keeps growing, while its identity is changed.