Virtues: The Valiant series of annual vinca won top praise in trial gardens last summer thanks to its ability to withstand heat and drought. Annual vinca blooms all summer with little upkeep. The gardeners at Kansas State University’s Prairie Star Flowers trial beds report that “(In 2015 and 2016), the trial gardens saw wet and cold springs followed by hot and dry summers. These plants were able to adapt to the changing weather very well and never showed signs of stress.”
Common name: Valiant annual vinca, annual periwinkle, Madagascar periwinkle
Botanical name: Catharanthus roseus Valiant series
Note: Annual vinca is different than, and not related to, perennial vinca, Vinca minor and Vinca major. The perennial vincas are shade-tolerant, winter-hardy ground covers that can be aggressive or invasive (particularly V. major), while annual vinca is a sun-loving low, bushy plant that cannot tolerate winters north of USDA Zone 10.
Exposure: Full sun
Season: Late spring to early fall, for flowers
Flowers: Flat, five-petaled flowers are held at the end of the upright stems. The Valiant series includes varieties in shades of white, pink and purple.
Foliage: Narrow dark green leaves line the stems and stand straight out.
Habit: Depending on the specific variety, Valiant vincas can reach 20 to 24 inches tall and about 20 inches wide. Valiant Lilac is a taller variety at 24 inches, while Valiant Burgundy, Valiant Apricot and Valiant Orchid stand about 20 inches tall.
Origins: Annual vinca is native to Madagascar. The Valiant series was introduced by Pan American Seed.
How to grow: Like other varieties, the Valiant vincas prefer full sun and well-drained soil in the ground or in containers. General-purpose fertilizer will help potted vinca keep blooming all summer. Avoid overwatering annual vinca. It is very drought tolerant, though it will appreciate watering during long dry spells. Deadheading is not necessary. In warm climates annual vinca may return by self-sown seed the following year.
Image of Valiant Lilac annual vinca courtesy of Prairie Star Flowers