• Vinca flowers create a splash of color in the garden.Jupiterimages/Photos.com/Getty Images
  
  Commonly named periwinkle, the genus Vinca contains perennial plants that are grown for their simple to variegated foliage and showy flowers. Many are grown as a ground cover or in a shrub border, where they grow vigorously. The long-stalked flowers are often blue or white to contrast nicely with the evergreen foliage. Flowers and foliage are ideal for brightening shady spots of the garden, as they often thrive in part shade.
  
  

Lesser Periwinkle

• Lesser periwinkle (Vinca minor), also called dwarf periwinkle or creeping myrtle, is a species of periwinkle that is often used as a ground cover. It grows up to 6 inches tall and up to 18 inches wide. It bears trailing stems with smooth, 1 ½-inch-long, evergreen leaves and can quickly become an attractive ground cover due to its ability to spread. The blue, phlox-like flowers on lesser periwinkle are 1 inch wide and appear in the leaf axils during spring. Lesser periwinkle grows best in full sun to part shade and moist, humus-rich soil, in USDA plant hardiness zones 4 to 8.
  
  

Greater Periwinkle

• Greater periwinkle (Vinca major), also called large periwinkle or blue buttons, is a mat-forming perennial with long, trailing stems. It grows up to 1½ feet tall and 1 to 2 feet wide and features dark green, 3-inch-long evergreen foliage that is ovate to lanceolate in shape. Greater periwinkle has a vigorous spreading capacity, where roots develop at the nodes when the stems come in contact with soil. Greater periwinkle produces tubular, solitary flowers that are phlox-like and violet to blue. The 1 ½-inch-wide flowers bloom along the upright stalks in spring and continue to flower sporadically throughout the summer and into fall. Greater periwinkle grows best in full sun to part shade and well-drained, humus-rich soil. It also has the ability to tolerate part to almost full shade. Grow greater periwinkle in USDA plant hardiness zones 7 to 9.
  
  

Variegated Greater Periwinkle

• Variegated greater periwinkle (Vinca major 'Variegata') is a trailing, evergreen ground cover that features dark green foliage with yellow to white edges. The texture on variegated greater periwinkle is coarser than lesser periwinkle, but it is not as hardy or aggressive. Variegated greater periwinkle has a vigorous growth rate and running habit. It grows 1 to 3 feet tall and bears blue, spring-blooming flowers. Variegated greater periwinkle grows best in full sun to shade and moist soil; it's best in USDA plant hardiness zones 7 to 11.