How to grow viola
Overview
Viola cornuta is a compact, cool-season perennial often grown as an annual, prized for its edible flowers and mild, floral flavour. It thrives in cool weather and light frost but struggles in heat, making timing and placement critical for success.
Varieties
- Penny Series — Compact, early-flowering mix with large flower colours – widely available in Australian nurseries.
- Sorbet Series — Dwarf, bushy plants with vivid, uniform flower colours; excellent for pots and borders.
- Jewel Series — Free-flowering and weather tolerant, offering a range of pastel and bright shades.
- Tiger Eye — Unique orange-yellow blooms with dark centre markings; good for novelty value.
Soil Preparation
Viola prefers rich, well-drained soil with a pH of 6.0–7.0. Incorporate plenty of compost or well-rotted manure before planting. Ensure the site does not become waterlogged, especially in heavy clay soils.
Growing Guide
Sow viola seeds 6 mm deep in rich, well-drained soil, spacing 20 cm between plants. Position in part shade with protection from harsh afternoon sun. Keep soil evenly moist but not soggy. Pinch back young plants to encourage bushiness. Deadhead spent flowers regularly to prolong blooming.
Sowing
Sow seeds 6 mm deep in trays or direct where they are to grow. Germinate in 7–14 days at 18–24°C. Transplant seedlings 25–30 cm apart when they have true leaves. Direct sowing is also effective in mild climates.
Care
Feed viola monthly with a balanced liquid fertiliser during active growth. Deadhead regularly to prevent seed formation and encourage rebloom. In late summer, cut back leggy growth to refresh the plant for autumn.
Companion Planting
Good companions include lettuce, spinach, kale, parsley, and pansies. Avoid planting near mint, which can compete vigorously. Violas benefit from the shade and moisture of taller cool-season greens.
Common Pests & Risks
Common pests include aphids (cluster on new growth), slugs, and snails. Control aphids by blasting with water or applying neem oil; manage slugs with barriers or organic pellets. Powdery mildew and leaf spots occur in humid conditions – improve air circulation and avoid overhead watering.
Harvesting
Harvest viola flowers when fully open, picking in the morning for best flavour and texture. Leaves can be picked as needed when young and tender. Use fresh immediately or store in a sealed container in the fridge for up to two days.
In the Kitchen
Use viola flowers fresh in salads, as garnishes for desserts and drinks, or frozen in ice cubes for a decorative touch. Leaves can be added to salads or used as a mild herb. Store in the fridge in a container with damp paper towel for up to 2 days.
Troubleshooting
Leggy growth: too little light or excess nitrogen – move to brighter spot and reduce feeding. Yellow leaves: overwatering or poor drainage – check soil moisture and improve drainage. Powdery mildew: humid, still air – increase spacing and airflow. Weak flowering: lack of deadheading or warm temperatures – remove spent blooms and plant in cooler season. Seedlings damp off: overly wet soil – use well-drained mix and avoid overwatering.