A member recently asked me why we didn't put the black plastic liners around the edge of the new PG and 11th green. Liners used to be a standard in the business. Now, not so much. The purpose is to prevent the surrounding native Clay-loam soils from "sucking" moisture out of the sand based green. By placing a 16" liner vertical, you separate the two soils. However, new research shows they can actually prevent the movement of gasses out of the root zone. Believe it or not, some courses with putting green turf issues are a result of the build up of toxic gasses in the root zone. Due to poorly designed drain outfalls and a lacking flush out port, the gasses that accumulate under the surface can not escape. This leads to turf decline.
If we lived in an arid climate where water management was more critical, these liners may be easier to justify. However, in our temperate rain forest Town of Highlands, we spend more time figuring out how to get rid of 90" of rain as opposed to adding it. On top of that, the amount of freeze thaw action we get pushes the liners out of the ground. They have become a maintenance headache because several times a year we need to send an employee out with a utility knife to, "trim the liners."
Contrary to what some think, these liners to NOT protect against outside turf contamination in the greens. Golf courses with bentgrass greens and bermudagrass surrounds offer a challenge. Those superintendents are constantly fighting the encroachment of bermudagrass into the putting greens. For that application, they do make a steel liner that allows Superintendents to run an edger along the steel to help control the bermudagrass.
