Darling 58

The Darling 58 is a genetically engineered American chestnut tree. The tree was created by American Chestnut Research & Restoration Program (ACRRP) at the State University of New York College of Environmental Science and Forestry (SUNY ESF) in collaboration with The American Chestnut Foundation (TACF) to restore the American chestnut to the forests of North America. These Darling-58 trees are attacked by chestnut blight, but survive. Darling-58 trees survive to reach maturity, produce chestnuts, and multiply to restore the American chestnut tree to the forests of North America. An error early in the breeding program resulted in use of an alternate cultivar, Darling 54 in some (if not all) field tests of the Darling 58 prior to the error's discovery in October 2023.

While The American Chestnut Foundation discontinued support of development of the Darling 58 cultivar in December 2023, in part due to the mistaken use of Darling 54 in all completed field trials, The American Chestnut Research & Restoration Program, who originated the tree, continues its development. The ACRRP has decided to build on top of the existing Darling 54 field trials and seek adoption of the Darling 54 tree instead. An updated petition containing a corrected list of field trials is expected in Summer 2025.