Viola riviniana
common dog-violet
Europe, western Asia, and North Africa
Overview
Viola riviniana is a low, clump-forming perennial in the Violaceae growing 2-6 inches (5-15 cm) tall and spreading by short rhizomes and self-seeding into loose patches. The heart-shaped leaves, about 1-3 inches (2.5-8 cm) across, form a basal rosette and persist through much of the year. Blue-violet flowers, each about 0.6-0.8 inch (1.5-2 cm) across, rise on slender stalks from spring into early summer, every flower with five petals and a pale, blunt spur at the back. Unlike sweet violet, its flowers carry no scent. After the spring flowers, the plant also forms closed, self-pollinating flowers near the ground that set seed without opening. It spreads readily by seed and can move into lawns and borders, which some gardeners treat as weedy. Hardy in USDA zones 4-8, it grows in partial shade to full sun in moist, well-drained soil. Native to Europe, including the British Isles, Viola riviniana grows in woodlands, hedge banks, grassland, and heaths, and serves as a food plant for the caterpillars of several fritillary butterflies.
Native Range
Viola riviniana is native to Europe, from the British Isles and Scandinavia south to the Mediterranean and east into western Asia and North Africa. It grows in woodland, hedge banks, grassland, heath, and rocky ground.Suggested Uses
Grown as groundcover in woodland gardens, shaded borders, and wildflower or grassland plantings. The low rosettes and seeding habit suit naturalized areas and the gaps between larger plants.How to Identify
Appearance
Size & Dimensions
Height2" - 6"
Width/Spread6" - 1'
Bloom Information
Blue-violet flowers open from spring into early summer, typically April to June, on slender upright stalks. Each flower lasts several days and the display continues for several weeks. Later in the season the plant forms closed flowers at ground level that set seed without opening.
Detailed Descriptions
Foliage Description
greenGrowing Conditions
Sun Requirements
Requires 3-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Viola riviniana grows in partial shade to full sun and tolerates most moist, well-drained soils with a pH of 5.5-7.5. It needs little care once established and copes with dry shade better than many woodland plants. It spreads by seed and short rhizomes and can move into lawns and beds, so it suits informal areas where some spread is welcome. Shearing after the main flush tidies the foliage. It needs no fertilizer in average soil. Slugs may graze the seedlings.Pruning
Shear or mow the foliage after the spring flush to tidy the rosettes and limit self-seeding. Removing seed pods before they ripen slows the spread into surrounding ground. Cut away dead leaves in late winter before new growth.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
summer
Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons