A YSE-led study published in Environmental Research Letters found that current federal rules regulating American ginseng harvest — based on plant age and leaf count — poorly predict the biological traits that matter most for conservation.
Ginseng, a wild plant prized in traditional medicine, can only be legally harvested once it's at least five years old and has three leaves. However, when researchers measured hundreds of ginseng plants, they found that age was a weak guide to how large a plant's root had grown or how many seeds it could produce.
The authors say switching to size-based harvest limits could do more to protect ginseng in the wild, while also making the rules easier for harvesters and forest farmers to follow.
The study was led by Karam C. Sheban ’26 PhD, and co-authored by Mark Bradford , the E.H. Harriman Professor of Soils and Ecosystem Ecology, and Marlyse C. Duguid , the Thomas J. Siccama Senior Lecturer in Field Ecology.
Environmental Research Letters
Protecting wild populations and working landscapes: the case for transitioning to size-based criteria for federal regulation of American ginseng
14-Jul-2026