Living On The Edge

        The cooler nighttime temps could not have come at a better time.  Saturday afternoon the poa annua on green number 5 really was struggling.  When soil temperatures reach 80 degrees, the plant begins to shut down.  When you see us hand watering greens, we are typically giving a quick "mist" over the plant to cool it down and get it through the remainder of the day.  We have actually been fortunate that there has not been excessive moisture, because these soil temps with excessive moisture basically creates a crock pot effect on the turf.  Our daytime high soil temps have been between 80-90 degrees since may, and we are literally forcing the turf to just barely hang on (hand watering, fungicide applications, cultural practices, and praying).  I think it's safe to say that most of us on the grounds staff are just barely hanging on as well.  Below are graphs showing soil temperatures for #3 green and the greens as a whole.  The other picture is a poa annua plant (most of the greens are 50-60% poa) with less than a .5" root system, and a pure bentgrass plant from the short game green with nearly 4" roots.  Obviously the soil at .5" is much warmer than the soil at 4-5".