In the United States, growers tend to grow only one or two major cultivars for regional and national markets but may grow several cultivars in small amounts for local markets. Despite the tremendous genetic variability available to breeders in almost all traits of sweetpotato, the crop is considered to be genetically vulnerable due to this heavy concentration in only one or two cultivars. The two cultivars which account for most of the current US acreage are 'Jewel' and 'Beauregard'. Roots are then placed in ground beds in late winter, covered with up to 5cm of soil and covered with plastic. Exact conditions and types of beds vary with location.
Plastic is removed after the threat of frost is over.
Typically roots will produce enough sprouts to begin planting in 5-6 weeks. Fertilizer is usually incorporated in the soil with an additional application approximately 6 weeks after planting. Phosphorous is also required but is only added in phosphorous deficient soils. Boron is usually added to prevent a surface defect known as blister. Herbicides are normally necessary for sweetpotato production but recommendations vary in different states.