Vinca minor, more likely to be known as periwinkle, creeping myrtle or just myrtle is a commonly used trailing, mat-forming evergreen ground cover. This plant is not only grown for its attractive shiny foliage, but the common name perfectly describes the pretty bloom color. The flowers are most numerous in mid spring, but plants will re-bloom sporadically throughout the growing season. There are some cultivars selected for different bloom color and variegated foliage.
The plant grows to about 6 inches tall, and, though it rarely sets seed, it spreads quickly by trailing branches that root everywhere they remain in contact with moist soil. Although originally native to Europe and Asia, periwinkle has spread from where it is cultivated here in the United States and is widely adapted and hardy throughout Indiana. Though it prefers rich, moist, fertile soil and partial shade, periwinkle will tolerate poor, dry soils and sunny exposures.
The same characteristics that make this plant so effective as a ground cover also contribute to it becoming an invasive plant. And the conditions that it particularly thrives in — rich, moist soil and shade — just happen to describe many natural woodland areas. Because of this potential to out compete native plants in natural areas, the Indiana Department of Natural Resources and the Indiana Plant Species Assessment Work Group (IPSAWG) recommends that plantings be restricted to areas bordered by sidewalks, lawn and other confined places.