Mowers are working overtime on many Florida golf courses. Increased rainfall, heat, and humidity have had a significant impact on turf growth and quality. Golf courses that were brown and dormant from drought stress six weeks ago are now quite healthy. In fact, some golf courses are now growing so much that it is difficult to keep up with daily mowing.
Mowing frequency is directly correlated to growth rate. As growth increases, so does the need for frequent mowing and mowers scalping into underlying stems causing turf to become yellow to tan in color. Constant scalping can have a negative impact on golf course aesthetics and turf health. Also, infrequent mowing at this time of year produces an abundance of clippings that must be dragged back into the turf canopy, if not, clumps of clippings will decrease golf course quality and injure the underlying turf through heat stress. Constant and heavy rainfall makes daily mowing difficult as lightning is unsafe for golf course staff. Tire rutting from mowers can occur when the soil becomes saturated.
Chemicals can be applied to reduce turf growth and are an excellent means of improving turf quality and management at this time of year. Plant growth regulators reduce specific growth hormones, causing a reduction in vertical turf growth. As a result, clippings are reduced and turf density is enhanced. Plant growth regulators reduce the need for intensive mowing and clipping removal, and improve golf course aesthetics. They are generally applied every three to four weeks on golf course fairways during summer months.
Putting greens also are growing aggressively at this time of year. Increased heat and humidity not only cause the turf to produce an abundance of new leaves, but thatch can swell and “grab” mowers, causing inconsistent scalping or washboarding. Increasing sand topdressing is recommended at this time to dilute thatch and provide a cushioning against mower scalping.
The increased turf growth on putting greens causes a decrease in putting speeds. The urge to lower mowing heights to improve putting speeds must be resisted, as the normal weather pattern calls for increased rainfall and cloudy weather over the next six to eight weeks. Plants produce their own food by photosynthesis through sunlight, and prolonged cloudy weather stresses putting greens. Mowing heights often are increased slightly during summer months to improve turf health. Double mowing and increased rolling is recommended to improve playing conditions in lieu of lower mowing.
Source: Todd Lowe, tlowe@usga.org or 941-828-2625