Spinach (Spinacia oleracea) is a hardy, cool-season crop that can be planted in early spring or fall throughout South Carolina. It can survive temperatures of 20 °F without injury, making it an excellent vegetable to harvest through the winter and into the spring, when given proper maintenance.
|Piedmont||Feb. 15 – April 15||Aug. 1 – Sept. 30|
|Central||Feb. 1 – April 1||Aug. 15 – Oct. 15|
|Coastal||Jan. 1 – April 1||Aug. 15 – Oct. 15|
Piedmont: Abbeville, Anderson, Cherokee, Chester, Edgefield, Fairfield, Greenville, Greenwood, Lancaster, Laurens, McCormick, Newberry, Oconee, Pickens, Saluda, Spartanburg, Union and York counties.
Central: Aiken, Allendale, Bamberg, Barnwell, Calhoun, Chesterfield, Clarendon, Darlington, Dillon, Florence, Kershaw, Lee, Lexington, Marion, Marlboro, Orangeburg, Richland and Sumter counties.
Coastal: Beaufort, Berkeley, Charleston, Colleton, Dorchester, Georgetown, Hampton, Horry, Jasper and Williamsburg counties.
Spinach grows well on a variety of soils, but it prefers a fertile sandy loam high in organic matter. Plant spinach in early spring to avoid high temperatures and long days, which cause the plants to bolt, or form flower stalks. The optimum soil temperature for spinach seed germination is 70 °F. Soil temperature above 85 °F will inhibit seed germination.
Plant spinach seed in rows 1 to 3 feet apart, spacing seed 2 inches apart in the row. Plant seed ½ inch deep and firm the soil over the seed to help ensure germination. Seed can also be broadcast on 12-inch wide beds. It is important to use new, fresh seed each year. Spinach seed that is more than a year old does not germinate well.
Raised beds that are approximately 3 inches high are good because the improved drainage may reduce the incidence of damping-off of young seedlings.
Most spinach that is grown in South Carolina is of the semi-savoy type. The savoy characteristic refers to the amount of leaf crinkle. Slow-bolting is an important varietal characteristic for overwintered and spring plantings. Bolting is the formation of the flower stalk. Resistance to downy mildew is another important characteristic in a spinach variety.
- Bloomsdale: semi-savoy, slow bolting
- Tyee: Semi-savoy, downy mildew resistant
- Whale: savoy type, downy mildew resistant, slow bolting
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. Spinach is sensitive to acidic soils; therefore, follow the results of a soil test to maintain a soil pH between 6.0 and 7.0.
Apply lime and pre-plant fertilizer according to soil test recommendations. Lime is best applied and tilled into the garden at least 3 months before planting. Broadcast the fertilizer evenly and incorporate it into the soil by tilling or disking to a depth of around 6 inches. Working the fertilizer into the soil ensures that the nutrients are available to the plants when they are seeded or transplanted.
Side dress 1 pound of calcium nitrate (15.5-0-0) per 100 square feet (30 feet of row) three to four weeks after planting. On sandier soil, this may need to be split into two applications. To avoid burning the roots, side-dress fertilizer 4 to 6 inches away from the plants. If fertilizer is broadcast, avoid burning the plant foliage by watering overhead after the application to wash fertilizer granules off the leaves.
Water the garden to provide a uniform moisture supply to the crop. The garden should be watered in the morning so that the foliage is dry before dark. This will reduce the development of foliar diseases. Water the garden sufficiently to moisten the soil to a depth of 6 inches. Light sprinklings will encourage shallow rooting of the plants. Spinach requires a consistent supply of moisture to produce a high-quality crop.
Weeds in the area can be controlled by using shallow cultivation. Do not cultivate deeply as this will damage the roots. Do not move soil toward the plants because spinach leaves that are covered by soil will rapidly rot.
Harvest & Storage
Spinach should be ready to harvest in about 37 to 45 days after planting. Harvest dark green, tender leaves that are 3 to 6 inches long by picking or cutting individual leaves. Start by picking the outer leaves and then harvest the newer leaves as they reach the desired size. Remove the petioles (leaf stems) if they are too large and fibrous. Rinse the spinach and dry it by using paper towels or a salad spinner. Spinach can be stored in plastic bags in the refrigerator.
Insect pests that may become a problem in growing spinach include aphids, cutworms, cabbage loopers, corn earworms, and diamondback moth caterpillars. Aphids are a significant problem because they transmit viruses to the plants.
The primary disease problems with this crop are downy mildew, white rust, and seedling damping-off. Use resistant varieties to avoid downy mildew.