Addressing shade issues is extremely important for both cool- and warm-season grasses. Evaluating shade issues during the summer is simple; all you need to do is make note of the shade cast on the turf. However, while no less important, evaluating shade during winter after all the leaves have fallen is more difficult.
Shade issues are common in the Northeast, and there are ample examples of when shade has caused turf decline. The winter of 2017-2018 was particularly damaging, especially for warm-season grass in the southern part of the region. In many instances, shade was a significant factor in the damage. Whether shade led to prolonged periods of snow or ice cover, exacerbated traffic stress, or made the turf weaker going into winter, there were clear correlations between shade and winter damage.
Fortunately, several tools are great for evaluating shade on a golf course. Google Earth, Google Maps, Bing! Maps and others are free and easy-to-use tools that allow you to evaluate shade issues by using satellite imagery. Unfortunately, satellite images can be outdated or of poor resolution, limiting their use. Another useful tool is sun-tracking applications for mobile phones or tablets. This tool allows you to evaluate the sun’s position relative to trees and other obstructions at different times of the year. Sun-tracking apps can generate images that objectively document shade issues. These images can help you communicate the need for selective pruning or tree removal. Lastly, specialty companies can do a detailed course evaluation of sunlight duration, impacts of individual or groupings of trees and projections of increased hours of sunlight if trees are removed.
Shade issues should be a consideration all year, not just during summer. Just because deciduous trees don’t have leaves during winter doesn’t mean that the negative impacts of shade will not occur. Evaluating and addressing shade issues to reduce turf problems during winter will help deliver healthier playing surfaces year-round.
Northeast Region Agronomists:
David A. Oatis, regional director – doatis@usga.org
Adam Moeller, director, Green Section Education – amoeller@usga.org
James E. Skorulski, agronomist – jskorulski@usga.org
Elliott Dowling, agronomist – edowling@usga.org
Paul Jacobs, agronomist – pjacobs@usga.org
Information on the USGA’s Course Consulting Service