Start seeds indoors now!
March is known for its unpredictable weather, but if you start seeds indoors, they’ll be protected and you’ll get a jump on your harvest. 
Seeds can be started in almost anything - paper cups, clean cell packs that have been rinsed with bleach water, and seed starting trays purchased from the garden center.
In his book Month-By-Month Gardening in the Carolinas, Bob Polomski says March is the month to start basil, chives, parsley, summer savoy, and sweet marjoran if you live in the Upstate. To encourage parsley to germinate, soak seeds in warm water overnight.
Broccoli, cabbage, and cauliflower seeds may also be started indoors now so that they will be ready to transplant in six to eight weeks.
If you live in the Piedmont, sow warm season vegetables in trays indoors. Try eggplant, heat-tolerant New Zealand spinach, pepper, and tomato. Bob also offers this VERY important advice: Sow the seeds of plants that dislike root disturbance in individual cups or peat pellets. They include cucumber, muskmelon, squash, and watermelon.
In the Coastal region of the state, plant perennial herbs like chives, oregano, and thyme when plants become available in garden centers. Now is the time to sow the seeds of parsley, dill, and beets, and Swiss chard.