Answer by
BrendaG (6111)
Periwinkle, also called Myrtle, dies in winter and grows from its root system in warm weather. Periwinkle is a hardy plant and will invade natural areas if left alone. Periwinkles bloom repeatedly from mid-spring to mid-fall, producing white, blue, and purple tinted flowers. As a ground cover, it keeps weeds at bay and few insects invade it.