1. Planting time of spring sweet potato in Huanghuai area: generally from late April to early May, and the temperature is stable above 65438 05℃.

2. Planting time of spring sweet potato in the north and plain areas with severe drought: it should be planted before May 1.

3. South Potato Region: Summer sweet potato is the main crop in the north, and it can be planted in the south all year round.

4. From the geographical distribution, sweet potato planting areas in the north and the middle and lower reaches of the Yangtze River can be planted early.

5. In terms of edible function, fresh spring sweet potato can be planted late. Taking Huanghuai area as an example, the planting time of spring sweet potato can be delayed by 10- 15 days.