The best time to plant sweet potatoes is from mid-April to mid-May. The specific planting time varies according to local climate changes and ambient temperature. The best time to plant sweet potato seedlings is when the soil is neither dry nor wet, and can be planted on cloudy days. If it is sunny and the temperature is high, it is suitable to plant in the afternoon. It is not suitable to plant sweet potatoes after heavy rain, as this can easily lead to root rot.