Apparently, only the top 2-3 inches of ground in Georgia ever freeze, so most plumbing below that level are pretty safe from freezing.
However, those faucets, valves (back flow prevention), and pipes exposed to the freezing weather are subject to damage.
Cover those exposed pipes or valves with foam, burlap bag, or other insulation material (some products are sold at home improvement stores).
Drain your sprinkler system – disconnect, drain, and store in a moderate temperature environment.
Know where your main water supply cut-off is located.
Also, keep mulch 12-18 inches from foundation of house to prevent creating warm, moist environment for insects and pests.
Source: MDJ. 12-8-2013, 2E