Alternative cool‐season turfgrass species for overseeding dormant bermudagrass

Abstract Bermudagrass is often overseeded with cool‐season turfgrass in the winter to provide an actively growing green surface during the winter and early spring. Perennial ryegrass ( Lolium perenne L.) is the most widely used cool‐season turfgrass for overseeding situations, but it can become a problematic weed following overseeding because of improved heat and drought tolerances. Therefore, other turfgrass species need to be evaluated to find alternatives that can provide a quality surface while also transitioning out after the overseeding season. The aim of this study is to investigate alternative cool‐season turfgrass species for overseeding dormant bermudagrass. Five annual ryegrass ( L. multiflorum Lam), two diploid (2 n  = 2 x  = 14) perennial ryegrasses ( L. perenne L.), three tetraploid (2 n  = 4 x  = 28) perennial ryegrasses, one meadow fescue ( Festuca pratensis Huds.), and two American ryegrass cultivars [× Festulolium loliaceum (Huds.)] were evaluated in this study. Visual ratings were taken monthly to assess performance traits such as turfgrass quality, color, density, and texture. Transition ratings were taken in May and December to evaluate the emergence of the bermudagrass in the spring and the survival of the cool‐season grasses through the summer. The perennial ryegrass cultivars had the highest average turfgrass quality ratings throughout the study. Two annual ryegrass cultivars also had high average turfgrass quality and were not statistically different from perennial ryegrass cultivars. The turf‐type annual ryegrass cultivars also transitioned out completely without herbicides, whereas significant survival of the diploid perennial ryegrasses was observed. Tetraploid ryegrass cultivars displayed a dark color throughout the overseeding season, but they did not transition any more than diploid perennial ryegrass. Newer, improved annual ryegrass cultivars appear to be a viable option for overseeding situations that want to avoid using cultural or chemical controls to induce the transition of cool‐season overseeding grasses in late spring.