The high food and vitamin content of the sweet potato makes it more valuable as a food than the Irish potato.
It requires considerable space. If the garden is small, it should be grown elsewhere as a field crop. A fertile, loamy, well drained soil is needed, but not one that is too rich. A fertilizer of high nitrogen content should not be used; 3 to 5% is sufficient. Four or 5 pounds per 100 feet of row.
Use a fertilizer rather high in phosphate and quite high in potash. An analysis such as 5-10-10 or 4-12-12 is good on many soils; but on sandier soils, usually low in potash, an analysis such as 3-9-or 3-9-18 is needed.
Do not use stable manure for sweet potato soils or hotbeds because of the danger of spreading diseases. There is also the likelihood of getting too much nitrogen which will cause rank vine growth.
Apply commercial fertilizer 10 days or two weeks before plants are to be set, either under the row and mixed or on either side of the row, as outlined for Irish potatoes.
Roots must not come in direct contact with fertilizer. Plant on high beds. Set a portion of the crop quite early so as to get vine cuttings for late settings.