Winter preparation. Ensure plantings have optimum moisture in their root zones, based on the species. Going into winter most plants other than cacti are less likely to be damaged during severe cold periods if they are properly irrigated. Maintain light to moderate moisture in their root zones and plant tissues. After inspecting all irrigation systems for proper function, top off any thin areas of mulch with the proper depth, according to mulch type. 2 inches is adequate for inorganic mulches, such as decomposed granite and other gravel. 3 inches is adequate for organic mulches in more lush plantings, such as shredded wood and pecan shells. In many cases, inorganic mulches wash to other areas over time. If you spot areas where the mulch depth is significantly over 2 inches, move and balance to cover thinner areas.