In a groundbreaking study, researchers have demonstrated the effectiveness of ethephon substrate drenches in controlling stem elongation in containerized herbaceous perennials. Conducted by W. Tyler Rich, a research associate at The Ohio State University, the study revealed that targeted applications of ethephon can regulate plant height without compromising plant health, enabling growers to produce uniform, high-quality plants for retail markets.
The findings are particularly significant for the ornamental horticulture industry, where plant aesthetics and operational efficiency are paramount. By offering a method to control growth, the study provides a viable solution to the challenges of producing visually appealing and market-ready plants.
Advancements in Growth Management for Annual Bedding Plants
Complementing the perennial study, another research effort focused on the impact of ethephon substrate drenches on annual bedding plants. This study quantified the effects of controlled ethephon applications, which resulted in more compact and aesthetically pleasing plants. The ability to limit excessive growth is a game-changer for growers seeking cost-effective and efficient growth management strategies in greenhouse and nursery production.
According to W. Garrett Owen, an extension specialist and assistant professor of Sustainable Greenhouse Nursery Systems, these insights are invaluable. He noted, “The research provides actionable information that helps growers enhance plant uniformity, reduce labor-intensive pruning, and improve overall crop marketability.”
Industry Implications and Sustainable Practices
The implications of these studies extend beyond aesthetics. Effective height and growth control are crucial for operational efficiency in ornamental horticulture. By reducing the need for labor-intensive practices such as pruning, growers can achieve more sustainable and profitable production methods. This research supports the adoption of ethephon drenches as a standard practice, offering a sustainable alternative to traditional growth control methods.
The studies were conducted to support the label expansion of Collate® 2L, the only ethephon product with EPA approval for substrate drench use as well as foliar sprays as of May 2025. This approval is a significant milestone, encouraging responsible use and application timing in floriculture production.
Expert Insights and Future Directions
W. Garrett Owen’s major program initiatives include floriculture crop production, plant nutrition and growth regulation, nutritional monitoring, and crop diagnostics. His expertise highlights the broader implications of these findings for the horticultural industry. “These studies are not just about controlling plant height,” Owen emphasized. “They represent a shift towards more sustainable practices that can significantly impact the industry’s future.”
For growers, the adoption of ethephon drenches could mean reduced costs and increased efficiency, leading to a more competitive edge in the market. As the industry continues to evolve, such innovations are likely to play a pivotal role in shaping its trajectory.
“By the Numbers: As of May 2025, Collate® 2L is the only ethephon product with EPA approval for substrate drench use.”
The full studies are available in the ASHS HortScience electronic journal, providing a comprehensive overview of the research and its implications. Established in 1903, the American Society for Horticultural Science (ASHS) is a leading professional society dedicated to promoting scientific research and education in horticulture.
With thousands of members worldwide, ASHS represents a diverse cross-section of the horticultural community, including scientists, educators, and industry professionals. The society focuses on a wide range of horticultural practices and challenges, from breeding and propagation to marketing and use of horticultural products.
For more information on these studies and to explore the full range of ASHS initiatives, visit ashs.org.
