Groundcover is used around foundations, for edging and for mass plantings. Groundcover stunts weed growth, prevents soil erosion and covers bare spots. Groundcovers can be woody or herbaceous, clumping or running, evergreen or deciduous. Vinca minor and vinca major are two closely related types of groundcover.
The vinca minor, or periwinkle, plant is considered an evergreen. It spreads rapidly to form dense plantings that remain attractive all year. In the spring brilliant blue, violet or purple flowers bloom. The leaves are rich, glossy, remain a dark green color and grow 4 to 6 inches long. Vinca minor is a non-climbing plant.
Vinca major, or big periwinkle, is also considered an evergreen. It spreads rapidly to form a dense carpet. The leaves are dark green and oval-shaped. Compared to vinca minor, it grows more upright. It has blue flowers and curving stems that can reach about 12 inches in height until they falls over and begin to spread. They root where the stem and leaves come together as they cover the ground. The leaves are in pairs, one on either side of the stem. The flowers bloom continually during the spring, but more infrequently during the summer.
Where to Grow
Vinca minor spreads by layering, meaning the shoots reach along the ground and root at the axis of the leaves. The new plants form from buds in the axis. This helps make it good groundcover because it self-propagates and spreads to form thick masses. It makes an excellent groundcover in shady sites, under large trees, along banks to prevent erosion or with other groundcovers to change the texture in the garden.
Vinca major is also good for soil erosion prevention on slopes or large bare areas. It is not as competitive against other plants or weeds as vinca minor. Spring bulbs could even be planted underneath it. Big periwinkle is also used for hanging baskets or window boxes, which allows for cascading over the edges
Vinca minor prefers part to full shade. If conditions are dry, it requires regular watering. To keep periwinkle healthy, it needs a balanced fertilizer and to be covered with compost during winter. The periwinkle is USDA zone hardy from 4 to 9.
Vinca major can tolerate full sun to part shade. The sun will provide more flowers and more covering foliage than shadier areas. It can tolerate dry soil but prefers some moisture. Big periwinkle is only USDA hardy in zones 7 to 9.
Both plants are very similar, with periwinkle being a slightly smaller version of big periwinkle. The leaves and flowers are smaller. They are similar in that they are both evergreens with blue flowers and dark green leaves. They also perform the same purposes in gardens, which is to provide groundcover in hard-to-grow areas. The only difference is that periwinkle is tolerant in colder zones and requires more shade.
All vincas are poisonous if ingested. When choosing a planting site for either, keep in mind small children and pets that may have access to the plants.