Water Resources Research Act Program

Details for Project ID 2015CO310B

Impact of Limited Irrigation on Health and Growth of Three Ornamental Grass Species

Institute: Colorado
Year Established: 2015 Start Date: 2015-03-01 End Date: 2016-02-29
Total Federal Funds: $5,000 Total Non-Federal Funds: $2,435

Principal Investigators: James Klett

Abstract: Throughout much of Colorado, the demand for water increases while the available water supply decreases. As a result, it is increasingly more important to conserve water wherever possible. One important way to conserve water is to plant low water use ornamental grasses in the urban landscape. Unfortunately, little scientific research has been conducted on determining the water use and drought tolerance of common ornamental grass species that are used in many urban landscapes and distributed through Colorado nurseries. Most plant species’ responses to limited irrigation are based solely upon opinion or visual observation. This study will be entering its third growing season, and therefore there is a need for a continuation of the ornamental grass water use study in order to produce significant and usable data. The research is conducted at the W.D. Holley Plant Environmental Research Center (PERC) at the Colorado State University campus in Fort Collins. The objective of this study is to determine the growth response of three ornamental grass species that are commonly marketed throughout Colorado nurseries and garden centers for planting in Colorado landscapes. The ornamental grasses will be subjected to progressively decreasing amounts of irrigation based on the evapotranspiration (ET) of a short reference crop. The three species being tested are Panicum virgatum ‘Rotstralbusch’ (Rotstralbusch Red Switch Grass), Schizachyrium scoparium ‘Blaze’ (Blaze Little Bluestem), and Calagramosis brachytricha (Korean Feather Reed Grass). Each species will be subjected to four levels of irrigation including 100%, 50%, 25%, with a 0% irrigation treatment plot will be used as a control. There will be two separate trials: In-ground trials, and mini-lysimeter trials. The in-ground trials will use all three species and will evaluate the water requirements of the three grass species, as well as overall visual characteristics. The mini-lysimeter trials will be conducted with one ornamental grass species (Schizachyrium scoparium ‘Blaze’, Blaze Little Bluestem) and will evaluate actual water usage and drought tolerance. Plants will be evaluated for predawn leaf water potential, growth habit, soil moisture, daily water loss, plant height/width, floral impact, color, winter survivability, and end of season leaf fresh/dry weights. A major goal of this study is to be the first scientific evaluation of drought tolerance and water requirements in ornamental grasses. Ornamental grasses are frequently used in the urban landscapes of Colorado and throughout the United States, however they are rarely, if ever, evaluated scientifically. This experiment will accurately evaluate water requirements, water usage, drought tolerance, visual appeal, and overall performance of three commonly used ornamental grass species.