How to Grow Viola Seeds

Grow Guide #2333
Family: Violaceae
Binomial name: Viola cornuta
Life Cycle: Perennial

This 'How to Grow' guide details everything a home gardener needs to know to plant, grow and care for Violas (Viola cornuta).

(Pansy (Viola wittrockiana) and viola (V. cornuta) are both members of the Viola family. Pansies have larger flowers, while violas have masses of smaller flowers. Both plants are grown in a similar way.)

When to Sow Viola Seeds

Viola is a cool season flower. Use the table below to identify the best time of year to sow viola seeds in your climate.

Preparation

Viola plants are best grown in full sun or part shade. Choose a location that will receive at least 3 hours of full sun each day.

Viola plants need a well drained soil enriched with plenty of organic matter. Prepare soil by weeding it thoroughly, digging it over to loosen it and adding aged animal manure or compost. Keep the area free of weeds until planting. Learn more about preparing soil for planting here.

Viola plants can be grown in containers. If possible choose a variety that’s recommended for container growing. Use a good quality potting mix and make sure your container is large enough for mature plants; a minimum of 10 litres is recommended for violas. During the growing season, keep in mind that container grown plants may need additional fertiliser to encourage healthy growth.

How to Sow Viola Seeds

Viola seeds do not require any treatment (eg soaking, stratification) before sowing.

Seeds of viola germinate best when they are not exposed to light. Sow seeds at the recommended depth and cover with enough soil to exclude light. Alternatively, you can place a board or some black plastic over the seeds while they germinate, removing it as soon as possible after the seeds have sprouted.

Viola seeds grow best when they are raised in trays or other containers and transplanted to the garden once established.

1. Fill trays, punnets or jiffy pots with a good quality seed-raising mix, or use soil starter pellets.
2. Sow seeds 6mm deep.
3. Keep soil moist but never wet or dry.
4. Seeds should germinate in around 4-7 days at a soil temperature of 17-21°C.
5. Transplant seedlings to the garden once they have their first true leaves and are large enough to handle (usually 5-10cm tall).
6. Plant out, spacing plants 15-30cm apart.

How to Grow Viola

Viola plants need regular watering during the growing season. Do not let soil dry out; keep soil evenly moist but not waterlogged. Water deeply in the early morning or late afternoon. Avoid watering the leaves of plants to avoid fungal diseases. Learn more about watering here.

If soil was well prepared no extra fertiliser should be necessary. In poor soil or to give your plants an extra boost, application of a high-potassium fertiliser or one formulated for flowering plants can be beneficial:

• Apply slow release fertiliser at the recommended rate when transplanting or when seedlings are 5-10cm tall.
• Apply liquid fertiliser at the recommended rate and frequency while plants are fruiting or flowering.

Viola plants should flower in approximately 110-120 days.

Deadhead viola flowers regularly during the growing season. Using sharp secateurs or snips cut fading or dead flowers off just above a set of leaves. Removing old flowers regularly will encourage plants to produce more flowers. Learn more about deadheading flowering plants here.

Common Problems when Growing Violas

Like all plants, viola is susceptible to some pests, diseases and other problems. Below is a list of the most common problems gardeners encounter when growing viola plants:

• 

  Aphids are small (2-4mm long) sap-sucking insects that congregate on the new shoots or the undersides of leaves. They can cause leaves to wilt or become discoloured, and also excrete honeydew which can attract ants and other insect pests. To manage aphids, remove them by spraying with a garden hose, apply a soap or alcohol spray, or encourage predatory insects to your garden. Read more about aphids here.
• 

  Bacterial leaf spot is a disease that causes irregularly shaped brown spots on all above-ground parts of a plant. The spots at first appear to be wet but become dry and scab-like over time. Leaves and flowers can fall prematurely. Water plants at soil level (not on the leaves), dispose of fallen leaves and fruit and practice crop rotation.
• 

  Downy mildew is a fungal disease that causes yellow to grey-brown patches on leaves, especially the undersides. Water plants at soil level (not on the leaves), remove and destroy affected leaves and do not overcrowd plants to ensure adequate air flow. If problems persist, spray with a homemade milk spray or fungicide.
• 

  Grey mould (Botrytis sp.) is a fungal disease that causes flowers to become mouldy and fruit to rot. Spores are transported by wind and can survive in soil or on green waste. The fungus spreads most in cool, damp weather. Prune off affected flowers and fruit, water plants at soil level (not on leaves) and if necessary spray with an appropriate fungicide or homemade spray.
• 

  Powdery mildew is caused by fungal spores reproducing on the leaves of plants. First showing as white spots on leaves, affected areas can spread quickly to cover the entire leaf surface. While rarely fatal, powdery mildew can reduce yields. Water plants at soil level (not on leaves) to prevent spreading spores, allow good air flow between plants, remove affected leaves and if necessary spray with an appropriate fungicide or homemade spray. Read more here about powdery mildew here.