If you have a choice, is it better to mow greens in the morning or evening?
Dr. James B. Beard, a leading turfgrass physiologist, recently commented about the time of day you choose to mow the greens. His knowledge of turf growth and development explains that there is a preferred time of day to mow.
Since the ball roll is being supported on the grass stems (shoots), stiff, uniform, upright stems can mean a lot to true roll and speed. Mowing in the morning will give a longer time of high-quality play during hours of play than mowing in afternoon or evening because of the way grass grows.
Beard explains: The major factor in mowing putting greens in the evening will be a slower putting speed or a shorter ball roll distance (BRD) the following day. About 60% to 65% of the daily vertical leaf extension (leaf growth) occurs at night. During darkness, the leaf stomata are closed and water loss by evapotranspiration essentially ceases; however, root water uptake continues and higher tissue turgidity normally results.
Since the vertical leaf extension involves the principle of cell elongation, tissue turgidity is important as a force of that elongation. The result is that there is much greater vertical leaf extension at night than during daylight hours. In summer this occurs regardless of the length of the daylight period, which is much longer than the nights of midsummer. Cloudy summer days would make it less of an issue, but the principle still holds true.
Mow in the morning if you have the choice.