1. The seedling raising time of purple sweet potato is suitable in late March, and it can't be later than early April at the latest. In northern China, the planting period of purple potato is generally late, from the beginning of May to the middle and late April in the solar calendar. During this period, the climate tends to be stable, and the temperature is just suitable for the growth of purple potato seedlings, which can greatly ensure the survival rate of purple potato seedlings and lay a foundation for high yield of purple potato.

2. The growth cycle of purple potato is generally between four and a half months and five months. If it is harvested too early, the immature purple potato will be scraped out, which will affect the yield of purple potato to a certain extent, and the development of dry matter contained in purple potato will be seriously damaged, so that the quality of purple potato will be greatly reduced after receiving.

3. Purple sweet potato belongs to the genus Ipomoea of Convolvulaceae, and its flesh is purple to deep purple, so it is also called black sweet potato, purple sweet potato or purple sweet potato.