Temperature-based growth potential (GP) in April and November

I’ve sometimes explained the temperature-based turfgrass growth potential (GP) of PACE Turf in relation to the grass conditions at the Masters Tournament.

The playing conditions at the Masters are superb, and the cool-season grass in that season is growing at near optimum temperatures. When the right work is done to prepare the surfaces, the weather is such in April that the cool-season grass can grow well.

I looked up the weather data for Bush Field Airport in Augusta for the past 30 years. Then I calculated the cool-season grass (C₃) GP for each day of the past 30 Masters Tournaments.

That’s pretty pleasant grass-growing (and golf-playing) weather. Some years stand out—I recall 2007 as an especially chilly year.

Taking average temperatures for each week, and then calculating the GP, one can see how the weekly GP has tended to be in the second week of April.

For the week of the Masters Tournament from 1990 to 2019, the average temperature at Bush Field has been 16.9 °C (62 °F). That temperature corresponds to a cool-season GP of 0.85 (85%).

For the month leading up to Masters Sunday in 1990 to 2019, the average temperature at Bush Field has been 15 °C (59 °F). That temperature corresponds to a GP of 0.66.

I wondered how these April growth potential calculations compared to November conditions. The Masters Tournament for 2020 has tentatively been scheduled for November 9 to 15.

From 1990 to 2019, the average temperature at Bush Field on those dates in November has been 12 °C (54 °F). That’s a GP of 0.35.

For the month leading up to November 15 from 1990 to 2019, the average temperature at Bush Field has been 15 °C (59 °F). That’s exactly the same as the month leading up to the April schedule, with the identical GP of 0.66.