Most years, South Carolina receives several inches of rain during the fall and winter. This year, however, we have been on the dry side. We have also been having warmer than average days, and your landscape may need supplemental irrigation.
Warm-season lawns appear to be dormant during the cooler months, but turfgrass crowns remain active year-round. Turfgrass crowns create new plant cells that turn into roots, stems, and grass blades. Creating new plants cells requires energy consumption, and water is essential to break down stored sugars into energy. If there is insufficient moisture in the soil, the crown can become dehydrated, and the metabolic processes stop. This is referred to as desiccation, and it can lead to winter kill. Centipede and St. Augustine turf are more susceptible to winter desiccation than other warm-season grasses.
Evergreen trees and shrubs can suffer from winter desiccation as well. Wind moving across the surface of leaves robs them of moisture, and our rollercoaster temperatures contribute to the need for supplemental irrigation during extended dry periods.
Plants don’t need a lot of water in the winter. A good rule of thumb is to apply irrigation if there hasn’t been any rainfall in 3- 4 weeks. Soil type and local site conditions will impact frequency and water needs. For more information on winter irrigation practices, see HGIC 1207, Watering Lawns, and HGIC 1803, Landscape Irrigation Management Part 4: Winter Irrigation & Winterizing.