Woody plants that may have potential for use in horticulture are the focus of my research. My ecological studies involve field research throughout North America, as well as physiological experiments conducted in greenhouses and laboratories. Research areas include nitrogen fixation involving horticultural landscape plants (both legumes and non-legumes); increasing sustainability of production of greenhouse and nursery crops; and historical trees, particularly on campuses of colleges and universities. I also lead a project to develop improved horticultural bioplastics. My graduate students have gone on to productive careers in industry and academia.