The term “Vinca” is commonly used in horticulture to describe two distinct types of ornamental plants that are not closely related botanically. One group comprises the true Vinca species (Vinca minor and Vinca major), which are perennial ground covers native to Europe and western Asia. The other plant often called Vinca is Catharanthus roseus, an annual bedding plant originating from Madagascar. Because they share a common name, identifying each plant by its physical characteristics can be confusing. This article provides a visual guide to the specific features that differentiate these two popular garden plants.
The Trailing Periwinkle Varieties
The perennial plants belonging to the genus Vinca are characterized by their trailing, mat-forming growth habit, making them excellent ground covers. These plants, often called periwinkle, possess long, slender stems that creep along the ground, rooting at the nodes where they touch the soil. This rooting mechanism allows them to spread rapidly and form a dense, low-growing carpet of foliage. The overall height of the plant rarely exceeds six to eight inches.
The foliage is a defining visual feature, remaining intact throughout the year as an evergreen. Leaves are small, typically one to two inches long, and arranged oppositely on the stem. They display a rich, dark green color and a distinctly glossy or waxy texture. Vinca minor has ovate or lance-shaped leaves, while Vinca major exhibits slightly larger leaves that are often broader with a heart-shaped base.
The flowers of these perennial Vincas appear primarily in the early spring, marking the first burst of color in the garden. They are small, usually about an inch or less in diameter, and somewhat delicate. Each flower has five petals fused at the base that spread outward to form a characteristic pinwheel shape. The most common color is a soft lavender-blue or violet, though white varieties are also cultivated. These solitary flowers emerge from the leaf axils, contrasting against the dark green backdrop of the evergreen leaves.
The Upright Annual Vinca
The plant known as the annual Vinca is scientifically classified as Catharanthus roseus, commonly referred to as Madagascar Periwinkle. Unlike its creeping counterpart, this plant has a decidedly upright and bushy growth habit, forming a dense, mounding structure. It is grown as a warm-season annual in most temperate climates, lasting from spring until the first frost of autumn. The overall height of a mature plant generally ranges from six to eighteen inches.
The leaves of Catharanthus roseus are generally larger than the perennial Vinca, displaying an oval to oblong shape. They are arranged in opposite pairs along the thick, often slightly reddish stems. The color is a medium to light green, and their texture is less glossy or leathery compared to the true Vinca species. A prominent, pale white midrib runs down the center of each leaf, providing a subtle visual distinction.
The flowers are the main ornamental draw, blooming continuously and profusely from early summer until the season’s end. These flowers are noticeably larger than the perennial variety, often measuring one to two inches across. They feature five distinct, flat, petal-like lobes, but the color palette is far more extensive and vibrant. Colors include white, deep pink, rose, magenta, and true red. Many popular cultivars feature a contrasting “eye,” which is a small, dark center color at the throat of the flower, enhancing its visual impact.
Key Visual Differences and Growth Context
The most immediate visual cue for distinguishing between the two plants is their overall growth habit. The true Vinca species (Vinca minor and Vinca major) is characterized by its low, perpetually trailing stems that act as a ground cover. Conversely, Catharanthus roseus is an upright, shrubby plant that forms a neat, dense mound in garden beds or containers. This difference in form is the quickest way to identify the plant.
Further differentiation involves examining the leaves and the timing of the blooms. Perennial Vincas possess dark, highly glossy, evergreen leaves, and their smaller, typically blue-violet flowers appear primarily during early spring. The annual Vinca, in contrast, has lighter green foliage with a more subtle sheen. It produces its larger, brightly colored flowers, including pinks and reds, throughout the hot summer months. The presence of a contrasting central “eye” is a feature almost exclusive to the annual variety.
The environmental setting also provides a strong hint for identification. The trailing, perennial Vinca is a shade-tolerant plant, often found thriving in wooded areas or under trees. The annual Catharanthus roseus, however, is a sun-loving plant that performs best in full sun locations, such as open flower beds or sunny containers. Therefore, a plant found aggressively creeping in a shady area is the perennial periwinkle, while the bushy, brightly colored plant dominating a sunny bed is the annual Vinca.