National Grass Trial Results from Eight States with 22 Cultivars, 2012-2015

Eights states Colorado, Minnesota, North Carolina, Ohio, Oregon, Pennsylvania, Texas A & M Overton, and Vermont completed three years of landscape evaluation of 17 switchgrass (Panicum virgatum) and five little bluestem (Schizachyrium scoparium) cultivars. Four locations in Florida (Fort Lauderdale, Fort Pierce, Quincy and Wimauma), one in Nebraska, and two in Texas (San Marcos and Lubbock) completed one or two years of the trials. 2012 was the establishment year and the following 3 years: 2013-15 were data collection years. All sites compiled data on plant height; width; flowering time; fall color; winter interest; pests; foliage color determined by Royal Horticultural Society’s color chart; plant form rating 1-5; flowering date; floral impact rating1-5; fall color; self-seeding rating 1-3-5; winter injury rating1-3-5; pests; overall landscape impact rating 1-5; and mortality. Texas A&M Overton, Florida (4 locations), and Vermont had the highest mortality rate. Florida locations lost nearly 50% of their plants by the second year. There was wide variation in the overall landscape value in different regions of the country, with only five of the 22 switchgrass cultivars receiving high ratings. Highest scoring switchgrass cultivars for overall landscape value (4.0 or higher using a 5.0 scale) at 4 or more locations were Cloud 9, Dallas Blues, Northwind, Shenandoah, and Thundercloud. Only one of the five little bluestem cultivars, Blue Heaven®, rated 4.0 or higher at four or more locations for overall landscape value. This evaluation shows the range of variability in plant performance across the country and the need for more trials evaluating perennials across North America.