In its native habitat, the potato is a perennial plant and survives from year to year as an underground stem, known as a tuber. The cropping cycle varies from 90 to 150 days depending upon the growing region. There are four stages of growth and development in the potato plant: vegetative growth, tuber initiation, tuber growth, and maturation. The growth pattern can be influenced by cultivars, age of seed pieces, weather, cultural practices, and pest damage; as well as a variety of other environmental factors.