I always bench mark the seasons by plant growth and color. Trees are always a first indicator, but grass plants tell a story to. Older Bentgrass varieties change color (Purple) when nighttime temperatures fall into the forties. Early last week, just past Labor Day, I noticed that our putting greens were not growing as actively as they were just a week before.
Greens mower operators were now dumping their buckets once per nine holes of cut. During the warm humid “corn growing” weather in July and August of this past year and with all the precipitation we received, our mower operators had to dump every other green or they would find excessive clipping residue left for our clean up lap cut. It was during that time as well that our Plant Growth Regulators were lasting but five days; not the two weeks we were budgeted for.
It is common knowledge that shorter days coupled with cooler nights trigger slower growth but I had a nagging question in my mind was it because they simply run out of steam due to a lack of fertility? Plant growth dictates when we should stop aerification knowing that the holes will no longer fully heal in this fall. Plant growth also tells us when supplemental fertilization will have limited negative impact on putting green speeds yet provides the plant with ample time to preload carbohydrates for winter survival. With changes in scientific study detecting when the plant absorbs and utilizes plant nutrients we will use the lack of plant growth to fertilize a full month before our normal "Late Season" application which is timed to the second killing frost. We always listen to Mother Nature.