Dr. Youbin Zheng and the University of Guelph Green Roof Research Team

Research Award

The 2014 Research Award of Excellence goes to the University of Guelph Green Roof Research Team for their publications of their research on green roof sedum plant production and maintenance. The article titled “Optimal Growing Substrate pH For Five Sedum Species”, published in HortScience in 2013, is the most recent piece of forward-thinking research published by this team. 

Sedum plants have been used in rock gardens and other landscape settings as ground covers for many years; currently they are in high demand due to the increasing popularity of green roof installations in North America and other parts of the world. The pH level of the growing substrate (i.e., soil substitute) impacts plant growth by influencing the availability of plant nutrients. 

Although Sedum can grow in a wide range of pH conditions, this study found growing substrate pH can have a significant influence on Sedum growth. Within optimal pH ranges, Sedum plants can grow many times faster than those grown out of these ranges. This is the first research to provide optimum growing substrate pH levels in order for growers to efficiently and rapidly produce good quality Sedum plants to meet the demand in many horticultural applications, including green roof plantings. This publication is critical in sedum green roof substrate formation and sedum green roof maintenance. Numerous green roof systems manufacturers have been using the results from this publication with great success. This research team is a good demonstration on how university led research can change and improve an industry’s practice.

Cities Alive 2014 Research Award of Excellence