SYRACUSE, N.Y. — The USDA has begun a 45-day open comment period for its review of genetically-grown chestnut tree, developed by researchers at the SUNY College of Environmental Science and Forestry (ESF). This open-comment period is the final step in the process of bringing the American chestnut tree back to northeastern forests, says ESF. 

The initial chestnut restoration project, developed by researchers at ESF, began in 1989 with initial discussions between founding members of the New York Chapter of The American Chestnut Foundation and ESF scientists. The project initially involved research into using genetic engineering to introduce blight resistance, with the first transgenic trees planted in field trials in 2006. 

In 2015, ESF announced the creation of the first line of transgenic blight-tolerant American chestnut trees, Darling 58, named it after an early supporter of the project, Herb Darling. 

USDA-APHIS started its review in 2020, followed by a public comment period in 2022 that drew thousands of positive responses from individuals and organizations nationwide. ESF submitted a revised petition in 2024 with a corrected name for the chestnut, Darling 54, following the labeling error in chromosomes of the plant that resulted in a pullback from supporters, along with additional updates to the original submission. The current USDA determination reconfirms the tree’s safety and completes this part of the regulatory pathway under the Plant Protection Act. 

The U.S. Department of Agriculture (USDA) completed its regulatory review of the Darling 54 American chestnut tree in June 2025, and issued a preliminary finding that it is “unlikely to pose a plant pest risk”. This decision by the USDA’s Animal and Plant Health Inspection Service (APHIS) represents a significant step toward restoring this iconic species to forests in the eastern United States.

The USDA-APHIS has begun a 45-day open comment period for its review of the Darling chestnut, marking the final step in this process.

“Submitting a comment by July 21 is a great way to show your support for the project,” said Dr. Andrew Newhouse, director of the American Chestnut Research & Restoration Project at ESF.

The Darling 54 variety was developed by ESF’s American Chestnut Research and Restoration Project in collaboration with American Chestnut Restoration, Inc., and SilvaBio, with support from other corporations. It is the first conservation-focused forest tree to complete a full USDA regulatory review. The project’s goal is to reintroduce diverse and resilient trees to help restore forest health and biodiversity.

“Planting more trees is critically important, but we need trees that can tolerate exotic pests and pathogens,” said Newhouse. “Darling 54 American chestnuts are safe, effective, and stable, with better blight tolerance than any American chestnut we’ve tested so far. ‘Darling’ and newer varieties now being developed will contribute to more resilient forests for future generations.”

While the USDA approval will put the project one step closer to distributing the Darling 54 chestnut, other regulatory agencies, such as the FDA, still have to complete their reviews of the tree.

“APHIS is one of three federal agencies reviewing Darling chestnuts, so while their approval is a considerable milestone for our project, other steps are necessary before Darling trees can be planted outside of research plots. This is the first time these agencies have evaluated a plant that is intended to persist in the wild, so the process is extensive and rigorous,” said Newhouse, “but once complete, it has the potential to facilitate other uses of biotechnology in conservation.”

To learn more, visit www.esf.edu.