December 21 has arrived, and for golf course superintendents across the southern United States, this is far more than just another date on the calendar. It is the winter solstice. Arguably, the most critical day of the year for warm-season turfgrass management.
The winter solstice marks the shortest day of the year. On this day, the sun rises and sets at its most southerly position and travels across the sky at its lowest annual angle. The cumulative result is reduced day length, diminished light intensity, and declining air and soil temperatures.
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| Sunrise on The Winter Solstice |
Ironically, this period of declining environmental support for turfgrass growth coincides with the busiest time of year for golf in Southwest Florida. Seasonal residents return, rounds increase, expectations remain high, and playing surfaces are asked to perform at peak levels, all while turfgrass is receiving the least amount of sunlight, and consequently experiencing the slowest growth, it will see all year.
From an agronomic standpoint, the importance of the winter solstice cannot be overstated.
Turfgrass health is driven by four fundamental inputs: sunlight (photosynthesis), water, air, and nutrients. While a superintendent can carefully manage irrigation, fertility, and cultural practices, sunlight remains the one variable largely outside our control. Understanding how the Earth’s rotation and seasonal sun angles influence turfgrass physiology is essential to successfully navigating this period. Trees and terrain that pose little concern in spring or summer can significantly restrict sunlight exposure during winter, further limiting photosynthetic opportunity and overall turfgrass performance.
At Olde Florida Golf Club, our playing surfaces are comprised of bermudagrass, a warm-season turfgrass species that performs optimally when average daily air temperatures exceed 75°F. Soil temperature is equally critical. Bermudagrass exhibits minimal growth when soil temperatures fall below 65°F, while optimal root growth occurs near 80°F. As day length shortens and sun angles decrease, both air and soil temperatures trend downward. Photosynthesis slows, carbohydrate production declines, and the plant’s ability to recover from traffic and stress is significantly reduced.
Because we cannot control the duration or intensity of sunlight, our management strategy must account for it well in advance. The goal is to have the turf in its strongest possible condition as we enter the winter golf season. From this point forward, our focus shifts from growth to preservation. For approximately the next 60 days, every decision, including mowing frequency, fertility timing, traffic management, and moisture control is made with the understanding that recovery will be slow and margins for error are narrow.
The encouraging news is that the winter solstice also represents a turning point!
Beginning tomorrow, the sun will gradually shift back to the north. Day length will increase by seconds at first, then minutes, and eventually hours. Sun angles will slowly rise, soil temperatures will stabilize, and photosynthetic capacity will begin to improve. While winter conditions will persist for several months, each passing day brings incrementally more environmental support for turfgrass growth.
For golfers, this time of year requires patience and understanding. While our team continues to work tirelessly each day, turfgrass simply does not respond as quickly as it does during the warmer months. Ball marks, divots, wear from cart and foot traffic, and other damage may linger longer, not due to neglect, but because the turf is operating with limited energy. Protecting the playing surfaces during this challenging period ensures they remain healthy, resilient, and enjoyable throughout the season.
