Soil temps, growth regulators, and height of cut.

Spring is officially here and the turf is starting to wake up from a long winter nap. The soil temps are warming up slightly and growth on greens is slowly increasing day to day. The photo below shows the soil  temperature at a depth of 1 1/2" on the putting green is 50 degrees.

The color of the turf on greens is slightly off due to application of two different growth regulators in the month. We use a product called Proxy to suppress seed head development which was applied three weeks ago, and we'll follow up with a second application next week. This should keep the seed head numbers very low to none at all. It has a slight growth regulating effect and turns the turf a little off color. Two weeks ago we made our first application of the year of a product called Primo, which  causes the plant to grow laterally, not vertically. It causes the turf to become much denser because the plant puts all it's energy into lateral growth. We apply it for the entire season until it gets cold and wet in October. Our first Primo application always causes the turf to turn slightly yellow as you see in the photo below.

The color on the greens will improve in the next week as the turf gets used to living with the Primo. The height of cut on greens was lowered yesterday from our winter cutting height of .130 to .115. That is the thickness of four sheets of printer paper shown below. After spring aeration we will make our way down another 15 thousandths of an inch to our summer cutting height of .100.

The thickness of four sheets is actually 14 and 1/2 thousandths (.0145) not 15, but very, very close. We set the height of cut on our greens mowers with a gauge in the shop. In the field we check the actual cutting height with a prism gauge shown below.

The angle in the photo is not quite right, but if you look closely you can see that the height of cut is under .125 (an eighth of an inch). This shows that the bench setting and the actual height of cut are very close.