Viola cornuta 'Blackout'
Common Name: horned violet
Type: Herbaceous perennial
Family: Violaceae
Zone: 6 to 10
Height: 0.50 to 0.75 feet
Spread: 0.50 to 1.00 feet
Bloom Time: April to June
Bloom Description: Black
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Suggested Use: Annual, Naturalize
Flower: Showy, Fragrant
Attracts: Butterflies
Tolerate: Deer, Black Walnut

Culture

Species plants are typically grown as perennials (winter hardy to USDA Zones 6-9), but may be grown as biennials/annuals in somewhat the same manner as pansies (see Viola x wittrockiana). They are easily grown in humusy, evenly moist, well-drained soils in full sun to part shade. Best in part shade in St. Louis. If flowering declines with the onset of hot summer weather, cut back plants to promote a possible fall rebloom.

Noteworthy Characteristics

Viola cornuta, commonly called horned violet or tufted violet, is a tufted perennial that grows to 6-8” tall and spreads by creeping, ascending stems to 12” wide. It is native to Spain and the Pyrenees. Small, fragrant, slender-spurred, pansy-like flowers (to 1.5” across) with spreading petals bloom in spring and summer. Flowers are mostly two-toned in shades of blue, violet and lavender. Cultivars expand the available colors to include shades of yellow, apricot, red and white. Round-toothed, ovate, evergreen leaves are subtended by large stipules.

Genus name comes from the Latin name for various sweet-scented flowers.

Specific epithet means horned.

'Blackout' is particularly noted for its quality black flower color. It is the result of a cross between V. 'Molly Sanderson' (female parent) and V. 'Highland Black' (male parent) which was taken in a controlled breeding program in Westerbork, the Netherlands in March of 2008. According to U. S. Plant Patent documents, 'Blackout' is distinguished from other black-flowered violas by its deep black flower color, medium green leaves, low growth vigor and outward-spreading mounded growth habit. U. S. Plant Patent PP23,369 was issued on January 29, 2013.

Problems

No serious insect or disease problems. Susceptible to fungal leaf diseases. Watch for slugs and snails.

Garden Uses

Borders, woodland gardens for plants grown as perennials. Bedding, window boxes and containers for plants grown as annuals.