Super Science: Managing shaded warm-season grass greens

Warm-season turfgrasses remain popular for putting greens in tropical, subtropical and transition zone climates, yet they suffer from poor shade and cold tolerance. Recently developed fine-textured zoysiagrass cultivars, such as Lazer, offer promising alternatives due to their greater shade tolerance.

A two-year field trial compared Lazer to TifEagle bermudagrass under different shade levels (0, 20, 40, 60 and 80 percent) and management regimes to assess minimum daily light integral (DLI) requirements and putting surface quality.

Species plots were further divided to include a low (0.100 inches) and high (0.125 inches) height of cut (HOC). The HOC treatments were further split to compare an untreated control to weekly applications of a plant growth regulator (PGR) (Primo Maxx; Syngenta Crop Protection).

In early 2020, Lazer had lower turf quality than TifEagle due to slower post-planting establishment, though it reached full coverage by late 2019. In both years, turf quality was affected by species, shade, PGRs and HOC.

In moderate shade (40–60 percent), Lazer generally performed better than TifEagle, particularly at higher HOC (0.125 inches). Under deep shade (60–80 percent), TifEagle declined rapidly, while Lazer maintained moderate quality.

Lazer exhibited unexpected sensitivity to the PGR trinexapac-ethyl, with early applications resulting in phytotoxicity and reduced quality. TifEagle benefited from TE, especially under moderate shade, suggesting lacking data on zoysiagrass PGR responses, warranting further research.

DLI measurements also showed Lazer required significantly less light than TifEagle depending on PGR use.

For ball roll distance, TifEagle outperformed Lazer on most dates, although both reached similar levels by the end of the season. Overall, Lazer zoysiagrass shows potential as a putting green surface in shaded, transition zone environments.

Reference

Adapted from the following journal article: Walton, T. E., McCalla, J. H., Karcher, D. E., Hutchens, W. J., Chandra, A., & Richardson, M. D. (2025). Shade, height of cut, and plant growth regulator effects on bermudagrass and zoysiagrass putting greens. Crop Science, 65, e21394. https://doi.org/10.1002/csc2.21394