Annual Vinca

Annual vinca or periwinkle (Catharanthus roseus) is a popular summer flower for hot, sunny flower beds.
Barbara H. Smith, ©2023 HGIC, Clemson Extension

With heat, drought, and poor soil tolerance, annual vinca (Catharanthus roseus), sometimes called periwinkle, is popular for summer flower beds in South Carolina.

Height/Spread

The plants grow 1 or 2 feet high and about the same width. There are new spreading types that are wider and lower. Most vinca have a dense, rounded form.

Growth Rate

Vinca is grown as a summer annual, but the seed will often self-sow around the garden the next year.

Ornamental Features

Annual vinca has durable, abundant flowers from May to frost. Many new cultivars are available in a wonderful selection of colors and larger flowers, with growth habits ranging from upright, dwarf, and creeping.

Vinca brightens a border when planted with Purple Heart (Tradescantia pallida).
Barbara H. Smith, ©2023 HGIC, Clemson Extension

Landscape Use

Vinca is an easy-to-grow summer annual for use in beds, borders, edging, and containers. It prefers full sun, tolerates heat and drought, and can be relied on to flower in the hottest weather throughout the entire summer.

Vinca takes a long time to flower when started from seed. It should only be planted outside once the ground is warm, usually in May when the soil temperatures are above 60° F. If planted too early, vinca often develops fungus problems or root rot. Improper pH may increase disease problems with vinca. It grows best in well-drained organic soils with a pH of 5.5 to 6.0 but will tolerate higher pH levels.

The spent flowers do not require deadheading to encourage more blooms or pinching to maintain a tidy growth habit.

Problems

Annual vinca is one of the most trouble-free bedding plants. Some diseases, such as root rots, stem rots, and foliar diebacks, can occur. Good drainage is important to prevent root rot diseases from occurring.

Annual Vinca (Catharanthus roseus) Cultivars:

• ‘Cora® XDR’ series has disease resistance for multiple strains of Phytophthora root rot. Height and width ranges from 12 to 16 inches tall and wide. This series has improved branching, which supports large, showy flowers that bloom profusely throughout the summer in pink, purple, and white solid colors along with bi-colors.
• ‘Heatwave’ grows to only 10 inches tall and is a compact grower, making this series a good choice for use in containers, hayracks, and in front of flower beds. This series is extremely heat tolerant and will grow in cooler temperatures than most annual vincas. It blooms early with large flowers in colors ranging from apricot, pink, raspberry, purple, white, and red.
• ‘Mediterranean’ series has a spreading growth habit, reaches only 6 inches tall, and spreads up to 2 feet wide. They can be used in hanging baskets, window boxes, and in the front of the flowerbed. Flower colors are available in peach, pink, purple, red, rose, and white.
• Mega Bloom® is the largest flowering vinca series grown from seed. It is 8 to 10 inches high and 10 to 12 inches wide. This series was bred to withstand heat and humidity and is highly disease resistant. Solid flower colors range from apricot, lavender, orchid, pink, purple, raspberry, and red. The pink and orchid halo varieties have a white circle around the center of the flower.
• ‘Pacifica’ series grows 14 inches tall and has large 2-inch-wide flowers with overlapping petals. This series is well-branched and early blooming. It is available in white, pink, rose, and light purples with or without contrasting “eyes”. ‘Pacifica Red’ is the first true red vinca.
• ‘Tattoo™’ series has flower petals that look like they have been airbrushed, giving them a watercolor effect. In this series, vinca varieties grow 10 to 14 inches tall and 6 to 8 inches wide; this series has a uniform, upright growth habit. Flower colors range from cherry, blueberry, orange, papaya, raspberry, and tangerine.
• ‘Titan™’ has a uniform growth habit and matures at a height of 14 to 16 inches and 10 to 12 inches wide. Due to the hybrid vigor, this series tolerates heat and drought better and can withstand cooler and wetter growing conditions. Flower colors in this series are available in apricot, pink, burgundy, cranberry, red, lavender, lilac, or white.
• ‘Valiant™’ has a well-branched growth habit and is 14 to 20 inches tall and 10 to 12 inches wide. The superior hybrid vigor of this series helps the plants to survive the hot sun, extreme heat and drought, and exposure to salt air. Available in various lower colors ranging from apricot, burgundy, lilac, punch, white, magenta, and orchid.