While visiting golf courses throughout the western United States over many years, there are a few commonalities I have observed among putting greens. First, regardless of budget, golf course superintendents and their teams do a heck of a job maintaining good-quality putting surfaces. The exceptional level of conditioning across many climates is impressive. While all courses have their unique challenges, the area of greens where turf tends to be the weakest is low-lying areas along the perimeter. I refer to these spots as the “terrible troughs.” These V-shaped areas are often found near the front of the green, they typically gather runoff and stay wet, and they make it difficult to achieve a clean, even cut with any kind of mower.
These troughs result in weak turf, regardless of grass species. For bentgrass or annual bluegrass, turf health in these areas declines in the middle of winter or summer. For bermudagrass, chronically high soil moisture and mowing challenges result in turf damage in winter and scalping in the summer. Turf damage in these troughs is exacerbated if they are in areas of concentrated foot traffic, in shade or on north-facing slopes.
These troughs will eventually need to be regraded to improve conditioning, but in the short term, here are some strategies that superintendents have employed to mitigate turf damage:
Turn off the water. These low-lying areas need to dry between overhead irrigation events. Use sprinklers infrequently near these areas and use hoses to address localized dry areas nearby.
Audit surrounding sprinklers. Make sure only greens sprinklers are watering these areas and adjust any surrounding heads as needed.
Conduct frequent venting. Use small-diameter solid or hollow tines or slicing tines to routinely vent these areas.
Use a separate “cleanup” mower. Set this mower at a slightly higher height of cut (0.010 to 0.020 inches higher) and use a solid front roller.
Apply additional sand topdressing. Extra sand in this perimeter pass may, over time, improve the grade to facilitate mowing and help dry out the surface by diluting organic matter.
Aerate and roll. Aggressive aeration and site-specific rolling with a greens roller or a 1- to 2-ton asphalt roller has helped some superintendents flatten V-shaped perimeter areas on their greens.
Try deep drilling. Some superintendents have used a long drill bit to create deep holes in these areas that they fill with sand. Beware though, this strategy may sound better than the results it ultimately achieves. It is worth trying and can help, but only temporarily.
While the above strategies will help reduce turf damage in these terrible troughs, the long-term solution is to regrade them, but it may be a bigger project than your green committee members expect. Fixing the grade likely requires removing sod several feet into the green and up to 15 feet into the green surrounds over a fairly wide area to properly tie in the grade. This work is usually best done by an experienced contractor and shaper. I have seen several in-house attempts to fix these troughs turn into a poorly graded mess, resulting in areas that negatively impact aesthetics and playability.
For courses looking to remove terrible troughs or discuss short-term strategies to improve turf health in these areas, reach out to your regional USGA agronomist.
West Region Agronomists:
Brian Whitlark, regional director – bwhitlark@usga.org
Cory Isom, senior consulting agronomist – cisom@usga.org