Recent studies published in HortScience highlight the effectiveness of ethephon substrate drenches in controlling stem elongation and overall growth in containerized herbaceous perennials and annual bedding plants. These findings offer growers practical tools to optimize plant quality, improve marketability, and manage growth in controlled production systems.
© American Society for Horticultural Sciences
Controlling stem elongation in perennials
One study evaluated the use of ethephon substrate drenches to regulate stem elongation in containerized herbaceous perennials. Results demonstrated that targeted applications can successfully control plant height without compromising overall plant health, allowing growers to produce uniform, high-quality plants suitable for retail markets.
Growth management in annual bedding plants
A complementary study quantified the effects of ethephon substrate drenches on a range of annual bedding plants. Researchers found that controlled applications can effectively limit excessive growth, resulting in more compact plants with improved aesthetic appeal. These insights provide valuable guidance for growers seeking cost-effective and efficient growth management strategies in greenhouse and nursery production.
Industry implications
Effective height and growth control are essential for both aesthetic quality and operational efficiency in ornamental horticulture. The research provides actionable information to help growers enhance plant uniformity, reduce labor-intensive pruning, and improve overall crop marketability, supporting more sustainable and profitable production practices.
This research was led by W. Tyler Rich, current research associate, as part of his Master of Science degree in the Department of Horticulture and Crop Science at The Ohio State University. The work was conducted to support label expansion of Collate® 2L (ethephon). As of May 2025, Collate ® 2L is the only ethephon product with EPA approval for substrate drench use as well as foliar sprays. These findings support grower adoption, application timing, and responsible use in floriculture production.
