Periwinkle is also called vinca or myrtle. Of the 12 species of periwinkle, two are popular groundcovers. All species have opposite leaves and single flowers. The perennial periwinkle should not be confused with the bedding plant, Madagascar periwinkle (Catharanthus roseus).
Periwinkle (Vinca minor) is an excellent evergreen groundcover with dark green foliage. Oblong to ovate leaves are opposite, simple, ½ to 2 inches long, glossy, with a short petiole. They exude a milky juice when broken. Flowers are purple, blue or white depending on the cultivar. Plants bloom in March or April and sometimes again in the fall. Vinca minor grows about 6 inches tall, spreading in all directions by sending out long trailing and rooting shoots, which make new plants.
Vinca major or large periwinkle is a larger, more aggressive species than V. minor. Leaves are up to 3 inches long. The blue, funnel-shaped flowers are 1 to 2 inches in diameter. They are borne in abundance in early spring and sporadically throughout the summer. Large periwinkle spreads rapidly and will mound up to 2 feet. Non-flowering stems root at the tips where they touch the ground.
Fact sheet: Periwinkle
Sold at Nassau County Master Gardener Plant Sale