Red-skinned potatoes can be grown as an early crop for new potatoes and as a late crop for storage.
Barbara H. Smith, ©2017 HGIC, Clemson Extension
Potatoes are a very easy and fun crop to grow in the home garden. White-skinned and red-skinned potatoes can be grown as an early crop for new potatoes and as a late crop for storage. Choose an early-maturing variety and a medium- to late-maturing variety if early and late harvests are desired.
Planting
Seed pieces should be cut three to five days before planting to allow the cut surfaces to heal.
Barbara H. Smith, ©2018 HGIC, Clemson Extension
Purchase only certified seed tubers for planting to help reduce disease problems. Saving your own seed potatoes is generally not worthwhile because viruses and diseases often appear next year. Seed potatoes should be firm and unsprouted. Use seed pieces that have at least one good eye and are about the size of 1- to 2-inch cubes. Seed pieces should be cut three to five days before planting to allow the cut surfaces to heal.
Plant potatoes in late winter (see planting chart). Plants will resist a light frost, but hard frosts and freezes may set back growth. Potatoes prefer a cool spring and moisture throughout the growing season.
Plant potatoes in furrows with the cut side down 3 to 5 inches deep.
Barbara H. Smith, ©2018 HGIC, Clemson Extension
Plant potatoes in furrows with the cut side down 3 to 5 inches deep. Later crops should be planted 5 to 6 inches deep. Space the seed pieces 8 to 10 inches apart. Pull a ridge of soil over each row when planting. Twelve pounds of seed potatoes will plant 100 feet of row.
Another method of growing potatoes is above-ground in mulch. Place seed pieces on top of the soil or 1 inch below soil level, and cover with a 12- to 18-inch layer of straw or pine needles. The tubers will form in the mulch. Harvesting is considerably easier using this method. Move the straw aside to harvest early potatoes. Replace straw to allow plants to produce more potatoes until the vines die.
Planting Dates
| Area | Spring | Fall |
| Coastal | Feb 1 – Mar 31 | Not Recommended |
| Piedmont | Mar 15 – Apr 30 | Not Recommended |
| Fall plantings are not recommended for South Carolina, owing to the increased risk of pest and disease development. | ||
Piedmont: Abbeville, Anderson, Cherokee, Chester, Chesterfield, Edgefield, Fairfield, Greenville, Greenwood, Kershaw, Lancaster, Laurens, Marlboro, McCormick, Newberry, Oconee, Pickens, Saluda, Spartanburg, Union, and York Counties.
Coastal Plain: Aiken, Allendale, Bamberg, Barnwell, Beaufort, Berkeley, Calhoun, Charleston, Clarendon, Colleton, Darlington, Dillon, Dorchester, Florence, Georgetown, Hampton, Horry, Jasper, Lee, Lexington, Marion, Orangeburg, Richland, Sumter, and Williamsburg Counties.
Fertilizing
A soil test is always the best method of determining the fertilization needs of the crop. Information on soil testing is available in HGIC 1652, Soil Testing.
Follow the soil test results to maintain a soil pH between 5.8 and 6.5 and optimal fertility levels. In gardens where potato scab is a problem, keeping the pH of the soil between 5.0 and 5.3 can significantly decrease the level of disease in susceptible varieties.
Watering
Water is critical when blossoms are forming, and irrigation should be applied if the soil at this time is very dry. Mulching can help conserve water, reduce weeds and keep soil temperatures lower. Potatoes will grow for an extended time when soil temperatures remain low, resulting in a bigger harvest.
Cultural Practices
Rake the surface occasionally to kill any weed seeds that germinate before the potato sprouts emerge. Later cultivation should be shallow and far enough from the rows to ensure no roots are damaged.
Just before the tops have grown too large to allow cultivation, a finishing cultivation, sometimes called “laying-by ” or “hilling-up,” is made. “Laying-by” is throwing soil over the potatoes to prevent exposure of the potatoes to the sun; exposure can cause greening or scalding. Green portions on potatoes are poisonous, taste bitter, and contain an alkaloid. Cut off and discard green areas before using.
The release of the new true seed potatoes is an interesting development. The major advantage of growing potatoes from seed is the decreased chance of disease. However, growing from seed pieces is generally less time-consuming for the home garden and will give better yields. True seed potatoes may be bred for higher yields with time, but at present, good quality stock potatoes yield the best crop.
Harvesting & Storage
Harvest potatoes for storage about two weeks after the vines die down in midsummer.
Barbara H. Smith, ©2017 HGIC, Clemson Extension
Potatoes average 100 to 120 days to maturity. Harvest potatoes after most of the vines have died; a spade fork is useful for digging. Handle the tubers as gently as possible during harvest. Avoid skinning tubers when digging and avoid long exposure to light. Leave the tubers exposed to the sun just long enough for the soil to dry and fall off (usually about one to two hours).
Potatoes for use in early summer (“new potatoes”) may be dug before the vines die. Dig early potatoes when tubers are large enough to eat.
Harvest potatoes for storage about two weeks after the vines die down in midsummer.
Late potatoes are best for winter storage. For six to eight months, potatoes can be stored in medium cool (40 to 50 ºF) moist (90 percent relative humidity) conditions. Sprouting is a problem when stored at higher temperatures.
Problems
Green skin (sun exposure), hollow heart (alternate wet and dry conditions), and black walnut wilt (located too close to a black walnut tree) are cultural problems that may occur.
Insect problems include Colorado potato beetle, wireworm, flea beetle, and potato leafhopper.
Diseases include early blight, late blight, common scab, brown rot, soft rot, and root-knot nematodes. See HGIC 2214, Irish & Sweet Potato Diseases; HGIC 2215, Sweet Potato & Irish Potato Insect Pests; and HGIC 2216, Root-Knot Nematodes in the Vegetable Garden.
Varieties
- Irish Cobbler
- Red Pontiac
- Kennebec (this cultivar has performed well in the Piedmont)
- Yukon Gold
See the HGIC fact sheets listed above for disease and insect pest-resistant varieties. If unable to locate the varieties needed, many good mail-order companies sell certified seed potatoes. A few are listed below:
Irish Eyes Garden Seeds
Washington State
(509) 933-7150
www.irisheyesgardenseeds.com
Johnny’s Selected Seed
955 Benton Ave.
Winslow, ME 04901
http://www.johnnyseeds.com
Park Seed Company
1 Parkton Ave.
Greenwood, SC 29647
(800) 213-0076
www.parkseed.com
Peaceful Valley Farm Supply
P.O. Box 2209
Grass Valley, CA 95945
(888)784-1722
http://www.groworganic.com
Seed Savers Exchange
3076 North Winn Rd.
Decorah, IA 52101
(563)382-5990
http://www.seedsavers.org
Territorial Seed Company
P.O. Box 158
Cottage Grove, OR 97424
(541)942-9547
http://www.territorial-seed.com
Vermont Bean Seed Company
334 W. Stroud St.
Randolph, WI 53956
(800)349-1071
http://vermontbean.com
Excerpted from the South Carolina Master Gardener Training Manual, EC 678.
Source: South Eastern Vegetable Crop Handbook 2021
Originally published 03/00
