South Carolina has three distinct regions: Piedmont in the northwest, Central in the middle part of the state, and Coastal along the coast. Gardeners in one region will have slightly different planting dates from gardeners in other parts of the state. Frost dates in the Piedmont can vary six months from comparable dates on the coast. Knowing the ideal planting dates for your area will ensure your vegetables get off to a good start.
Sweet corn is planted in the spring in all three regions of South Carolina, and it can be planted once every one to two weeks during the planting period to get a longer harvesting season.
Sweet corn's first planting is between April 15 to April 30 in the Piedmont region, March 20 to April 30 in the Central region, and March 10 to April 30 in the Coastal region.
Snap beans, or bush beans, can be planted from April 15 to April 30 in the spring and Aug. 1 through Aug. 15 in the late summer in the Piedmont region. Plant snap beans in the Central region from April 1 to April 15 and Aug. 5 through Aug. 20. For the Coastal section of the state, spring planting is March 15 through 30, and the later planting is Aug. 15 to Aug. 30.
Summer squash also can be planted spring and late summer in all three South Carolina regions. In the Piedmont, plant from April 15 to May 15 and July 1 to July 20. The Central region can plant from April 1 to April 20 and Aug. 1 to Aug. 15. On the coast, plant summer squash March 20 to April 10 and Aug. 10 to Aug. 20.
Transplanted tomato plants can be set out May 1 to May 30 and July 10 to July 20 in the Piedmont region; April 5 to April 25 or July 10 to July 20 in the Central region; and March 25 to April 10 or July 25 to July 30 in the Coastal region.
Lettuce is a cool-weather crop planted in the Piedmont from March 1 to March 15 or Aug. 15 to Aug. 25. Plant lettuce Feb. 1 to Feb. 28 and Aug. 15 to Aug. 25 in the Central region, and Dec. 20 to Feb. 5 or Aug. 15 to Aug 25 in the Coastal region.
Onion planting times vary according to whether you're putting in onion plants or onion sets.
For onion plants: March 1 to 30 for Piedmont, Feb. 15 to March 15 for Central, and Feb. 1 to March 1 for Coastal.
Onion sets can be planted twice each year. In the Piedmont, put sets in from March 1 to March 30 or Sept. 1 to Oct. 30. Plant sets from Feb. 15 to March 15 or Sept. 15 to Nov. 15 in the Central region. In the Coastal area, plant them Feb. 1 to March 1 or Oct. 1 to Nov. 30.