Humidity Sucks
There is no better way to put it than to say that for bentgrass, humidity sucks. Bentgrass declines rapidly when dew points reach 65-70°. When air humidity is high for extended time periods, bentgrass stops moving water out of the soil. The process of evapotranspiration stops and plants essentially stew in their own juices. Roots suffocate and plants thin and die. Pocketed and shaded greens suffer first and suffer fast. Poa does fine. It’s a weed and has no problem with saturation. That is its preferred condition and why most push-ups are Poa. People often think that it is heat that kills bentgrass but this is not strictly true. Shadow Creek in Las Vegas is a great example. With bentgrass tees and greens, it performs flawlessly, even in 105° heat. But as the saying goes “It’s a dry heat!” Obviously, not all CBG varieties are suited to that level of heat but in general, wet soil and wet air kill bentgrass, not heat. So punch some holes and pull out the fans. And lets hope this is a short summer….