Establishing a Common-Garden Experiment to Evaluate Cold Hardiness of Southwestern Creosote Bush (Larrea tridentata) for Water-Wise Landscaping in Southern Idaho
Faculty Mentor Information
Bill Ebener, College of Southern Idaho; Deserae Orton, Orton Botanical Garden; and Jeremy Starkey, College of Southern Idaho
Presentation Date
7-15-2026
Abstract
Water conservation is an increasing priority in southern Idaho, where interest in drought-tolerant landscaping continues to grow. Creosote bush (Larrea tridentata) is one of North America's most drought-adapted shrubs, yet its potential for cultivation in colder climates remains largely unknown. This project establishes a common-garden experiment to evaluate whether populations collected from different portions of the species' range differ in their ability to tolerate Idaho winters. Juvenile creosote plants were collected from three habitats representing distinct climatic conditions: a cold-edge population in central New Mexico, a southern Mojave Desert population in California, and a northern Mojave population near Crystal Springs, Nevada. Habitat characteristics, qualitative assessments of plant vigor, and soil samples were recorded during collection. Initial field observations indicated generally vigorous plants in New Mexico, while the southern Mojave population exhibited greater signs of seasonal water stress or dormancy. Following transplantation to the Orton Botanical Garden in Twin Falls, Idaho, plants will undergo an establishment period before being assigned to outdoor or greenhouse overwintering treatments. Long-term monitoring will compare survival, health, and growth among populations. This project provides the foundation for evaluating geographic variation in cold hardiness while exploring the potential for water-wise landscaping, wildfire prevention, and conservation applications in southern Idaho.
Establishing a Common-Garden Experiment to Evaluate Cold Hardiness of Southwestern Creosote Bush (Larrea tridentata) for Water-Wise Landscaping in Southern Idaho
Water conservation is an increasing priority in southern Idaho, where interest in drought-tolerant landscaping continues to grow. Creosote bush (Larrea tridentata) is one of North America's most drought-adapted shrubs, yet its potential for cultivation in colder climates remains largely unknown. This project establishes a common-garden experiment to evaluate whether populations collected from different portions of the species' range differ in their ability to tolerate Idaho winters. Juvenile creosote plants were collected from three habitats representing distinct climatic conditions: a cold-edge population in central New Mexico, a southern Mojave Desert population in California, and a northern Mojave population near Crystal Springs, Nevada. Habitat characteristics, qualitative assessments of plant vigor, and soil samples were recorded during collection. Initial field observations indicated generally vigorous plants in New Mexico, while the southern Mojave population exhibited greater signs of seasonal water stress or dormancy. Following transplantation to the Orton Botanical Garden in Twin Falls, Idaho, plants will undergo an establishment period before being assigned to outdoor or greenhouse overwintering treatments. Long-term monitoring will compare survival, health, and growth among populations. This project provides the foundation for evaluating geographic variation in cold hardiness while exploring the potential for water-wise landscaping, wildfire prevention, and conservation applications in southern Idaho.