Vinca major
Periwinkle is a vigorous, fast-spreading evergreen groundcover with arching and trailing stems that root at the nodes, mounding to roughly 12 to 18 inches and covering large areas quickly. It grows in part shade to shade with low to moderate water once established and adapts to most soils, bearing violet-blue, five-lobed flowers in spring. Its larger leaves and stronger spread set it apart from the more restrained Vinca minor, so site it where rapid coverage is the goal. Use it for shaded slopes, bank stabilization, and erosion control on difficult, hard-to-mow ground.