Vinca major and vinca minor are both commonly planted in flower gardens. Both vines that offer excellent coverage for rock walls and as ground covers, the two forms of vinca continue to be a great option for time-pressed gardeners.
Vinca major is also known as big periwinkle. It's famed for its beautiful shade of blue, and is an excellent ground cover for holding back soil erosion. According to the USDA, it can thrive throughout the southern U.S., and north along the East and West Coasts, but isn't normally found in the Midwest. It is considered potentially invasive in some states, notes the USDA.
Vinca minor, also known as common periwinkle, has lovely deep blue or purple flowers. Like vinca major it is a ground cover ideally suited to shaded areas and is a perennial and evergreen, making it ideal for year-long coverage of areas vulnerable to erosion and well-adapted to most types of soil, according to Floridata.
The chief difference between vinca major and vinca minor is their size, according to Floridata, with vinca minor flowers being approximately 1 inch across, while vinca major flowers measure double that. Another key difference, according to the USDA, is that vinca minor withstands far more diverse growing conditions and can be successfully grown in the Midwest states and as far north as Montana and southern Canada.