Vinca, also known as periwinkle, is a popular choice for gardeners due to its attractive foliage and vibrant blooms. This versatile plant serves effectively as a groundcover, thriving in various landscape settings. Its relatively easy care requirements and adaptability make it a favored option for both novice and experienced gardeners.
Understanding Vinca Varieties
Vinca includes several varieties, with Vinca minor and Vinca major being the most common. Vinca minor, or dwarf periwinkle, is a herbaceous perennial with dense evergreen foliage. It typically grows 0.25 to 0.50 feet tall and spreads 0.50 to 1.50 feet, producing lavender-blue, phlox-like flowers from spring through fall. This variety is hardy in USDA Zones 4 to 8, tolerates full sun to partial shade, and adapts to various soil types, including rocky or shallow soils.
Vinca major, or bigleaf periwinkle, is an evergreen perennial with larger leaves, up to 3 inches long. Its solitary, pale violet-blue flowers, about 1.5 inches across, appear on upright stalks from spring into autumn. Hardy in USDA Zones 7 to 9, Vinca major spreads aggressively, rooting at nodes where stems touch the soil. Both Vinca minor and Vinca major can be invasive in some regions; check local regulations before planting.
Planting and Growing Vinca
Vinca plants prefer well-draining soil and tolerate a range of light conditions. While annual varieties thrive in full sun, perennial types like Vinca minor adapt to partial or full shade. Enriching the soil with compost can improve plant health, though Vinca grows in various soil types, including sandy, loamy, or clay, provided there is good drainage.
For planting, ensure soil temperature is above 60°F to prevent fungal problems and root rot. When transplanting nursery plants, position them at the same depth as their original containers. Space plants about 8 inches apart for quick groundcover, or 12-18 inches for larger areas. After planting, water thoroughly to help the soil settle around the roots.
Ongoing Vinca Care
Established Vinca plants are drought-tolerant, but consistent watering is important. Water when the top 1-2 inches of soil feel dry to the touch. Allowing the soil to dry between waterings prevents root rot and other issues. Watering in the early morning helps foliage dry, reducing the risk of fungal diseases.
Vinca plants are not heavy feeders, but monthly fertilization can promote better blooming and vibrant foliage. A balanced 10-10-10 water-soluble fertilizer is recommended, applied after watering. Avoid nitrogen-rich fertilizers, which encourage leaf production over flowers. Trim Vinca to control spread or maintain shape and density. Leggy plants often indicate insufficient sunlight.
Propagating Vinca
Vinca can be propagated to expand plantings. Stem cuttings are a common method. Select a healthy, non-flowering stem 4 to 6 inches long. Remove leaves from the lower half, making a clean cut just below a leaf node.
Cuttings can be rooted in water or a well-draining potting mix. In water, ensure the stem section where leaves were removed is fully immersed; roots typically form within 2-3 weeks. For soil, insert the cutting into a mix of perlite and peat moss or sandy soil, keeping it consistently moist but not waterlogged. Place the potted cutting in a warm spot with bright, indirect light.
Division is another method, best performed in early to mid-autumn when the plant is not blooming. Water the plant the night before, then dig around the rootball, gently pry it loose, and divide it into sections, ensuring each has an equal share of stems and roots.
Common Vinca Issues
Vinca plants are resilient but can face problems. Yellowing leaves often signal environmental stress, including insufficient drainage or overwatering. Continuously wet soil deprives roots of oxygen, making them susceptible to fungal diseases like root rot.
Nutritional deficiencies, particularly nitrogen or magnesium, can also cause yellowing. Recent transplanting might cause temporary yellowing as the plant adjusts. Pests like aphids and nematodes can affect Vinca, and diseases such as leaf spot and blight are possible. Good drainage prevents root rot. If fungal diseases occur, remove affected foliage to prevent spread.