Viola: Indoor or Direct Sow or Potted Plant Annual
How to Sow and Plant
Viola may be grown from seed sown early indoors and transplanted outside after frost or planted as a potted plant.
Sowing Seed Indoors:
- Sow indoors 8-12 weeks before the last heavy frost using a seed starting kit. Violas can take a light frost. They may also be started late summer for fall blooming.
- Sow seeds thinly and evenly in seed starting formula. Cover completely as seeds need darkness to germinate; firm lightly and keep evenly moist.
- Seedlings emerge in 10-14 days
- As soon as seedlings emerge, provide plenty of light on a sunny windowsill or grow seedlings 3-4 inches beneath fluorescent plant lights turned on 16 hours per day, off for 8 hours at night. Raise the lights as the plants grow taller. Incandescent bulbs will not work for this process because they will get too hot. Most plants require a dark period to grow, do not leave lights on for 24 hours.
- Thin to one seedling per cell when they have two sets of leaves.
- Seedlings do not need much fertilizer, feed when they are 3-4 weeks old using a starter solution (half strength of a complete indoor houseplant food) according to manufacturer’s directions.
- Transplant hardened-off seedlings to the garden after the heavy frost.
- Before planting in the garden, seedling plants need to be “hardened off”. Accustom young plants to outdoor conditions by moving them to a sheltered place outside for a week. Be sure to protect them from wind and hot sun at first. If frost threatens at night, cover or bring containers indoors, then take them out again in the morning. This hardening off process toughens the plant’s cell structure and reduces transplant shock and scalding.
Sowing Directly in the Garden:
- Direct sow in full sun to part shade in well-drained soil in early spring in the North, or fall in the South.
- Prepare the soil by removing weeds and working organic matter into the top 6-8 inches of soil; then level and smooth.
- Most plants respond well to soils amended with organic matter. Compost is a wonderful form of organic matter with a good balance of nutrients and an ideal pH level, it can be added to your planting area at any time. If compost is not available, top dress the soil after planting with 1-2 inches of organic mulch, which will begin to breakdown into compost. After the growing season, a soil test will indicate what soil amendments are needed for the following season.
- Sow thinly and evenly and cover with ¼ inch of fine soil.
- Firm lightly and keep evenly moist.
- Seedlings emerge in 7-14 days depending on the soil and weather conditions.
Planting in the Garden:
- Select a location in full sun to part shade with well-drained soil.
- Prepare the bed by turning the soil under to a depth of 6-12, inches removing any debris, and lightly raking as level as possible.
- The addition of organic matter (leaf mold, compost, well-rotted manure) benefits all gardens and is essential in recently constructed neighborhoods.
- Plant on a cloudy day or in late afternoon to reduce transplant shock.
- Dig a hole for each plant, approximately 12-14 inches apart large enough to amply accommodate the root ball.
- Unpot the plant and gently loosen the root ball with your hands to encourage good root growth.
- Place the top of the root ball even with the level of the surrounding soil. Fill with soil to the top of the root ball. Press soil down firmly with your hand.
- Use the plant tag as a location marker.
- Water well.
How to Grow
- Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their seeds from germinating.
- Mulches also help retain soil moisture and maintain even soil temperatures. For annuals an organic mulch of shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
- Plants need about 1 inch of rain per week during the growing season. Use a rain gauge to check to see if you need to add water. It's best to water with a drip or trickle system that delivers water at low pressure at the soil level. If you water with overhead sprinklers, water early in the day so the foliage has time to dry off before evening, to minimize disease problems. Keep the soil moist but not saturated.
- Until plants become established, some protection from extreme winds and direct, hot sunlight may be necessary. Good air movement is also important.
- After new growth appears, a light fertilizer may be applied. Keep granular fertilizers away from the plant crown and foliage to avoid burn injury. Use low rates of a slow release fertilizer, as higher rates may encourage root rots.
- Remove spent flower heads to keep plants flowering.
- Monitor for pests and diseases. Check with your local Cooperative Extension Service for pest controls recommended for your area.
- Fall planted plants will bloom until there is a hard frost. They will reappear in spring and may die back in the heat of the following summer.
Growing Tips
- Violas can be cut back in midsummer as they get scraggly, which encourages new growth and re-blooming when cool temperatures return in the fall.
- Add violas to mixed plantings with low-growing perennials.
- They are pretty groundcovers, excellent under deciduous trees, and can be used alone or with other plants such as common periwinkle.
- Use violas anywhere you need an extra touch of color in spring-among other edging plants, with spring bulbs, in containers, and mixed beds and borders.
- Flowers are edible and can be added to salads or used to garnish plates.
Common Disease Problems
Alternaria Leaf Spot: Small, round reddish brown spots with white to grey centers form on the upper surface of the leaves and along the midrib. The lesions may encircle the stems and cause wilt. This disease is worse in warm, wet or very humid weather. Burpee Recommends: Avoid getting water on the foliage. Remove infected plant parts and do not work around wet plants. Provide plenty of air circulation. Contact your Cooperative Extension Service for fungicide recommendations.
Botrytis: This fungus causes a grey mold on flowers, leaves, stems and buds. It thrives in cool wet weather conditions. Burpee Recommends: Remove affected plant parts, avoid watering at night and getting water on the plant when watering. Make sure plants have good air circulation. Contact your Cooperative Extension Service for fungicide recommendations.
Damping Off: This is one of the most common problems when starting plants from seed. The seedling emerges and appears healthy; then it suddenly wilts and dies for no obvious reason. Damping off is caused by a fungus that is active when there is abundant moisture and soils and air temperatures are above 68 degrees F. Typically, this indicates that the soil is too wet or contains high amounts of nitrogen fertilizer. Burpee Recommends: Keep seedlings moist but do not overwater; avoid over-fertilizing your seedlings; thin out seedlings to avoid overcrowding; make sure the plants are getting good air circulation; if you plant in containers, thoroughly wash them in soapy water and rinse in a ten per cent bleach solution after use.
Powdery Mildew: This fungus disease occurs on the top of the leaves in humid weather conditions. The leaves appear to have a whitish or greyish surface and may curl. Burpee Recommends: Avoid powdery mildew by providing good air circulation for the plants by good spacing and pruning. Contact your Cooperative Extension Service for fungicide recommendations.
Rust: A number of fungus diseases that rust colored spots on foliage, stalks and husks. Burpee Recommends: Plant early as these diseases tend to be worse later in the season. Practice crop rotation. Remove infected plants.
Common Pest and Cultural Problems
Aphids: Greenish, red, black or peach colored sucking insects that can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Flea Beetles: These small hopping beetles feed on plant foliage and may spread diseases. Burpee Recommends: Rotate crops. Use floating row covers to prevent damage to young foliage.
Gall Midges: Adults are tiny flies usually with long antennae resembling a fruit fly. Larvae are tiny yellow to orange maggots that can be found inside the galls feeding on the plant. Galls are distortions or lumps of plant tissue on plant leaves or stems. Burpee recommends: Removing infected leaves from the garden. If there are a lot of galls on the plant, remove and destroy the infected plant.
Spider Mites: These tiny spider-like pests are about the size of a grain of pepper. They may be red, black, brown or yellow. They suck on the plant juices removing chlorophyll and injecting toxins which cause white dots on the foliage. There is often webbing visible on the plant. They cause the foliage to turn yellow and become dry and stippled. They multiply quickly and thrive in dry conditions. Burpee Recommends: Spider mites may be controlled with a forceful spray every other day. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for miticide recommendations.
Thrips: Thrips are tiny needle-thin insects that are black or straw colored. They suck the juices of plants and attack flower petals, leaves and stems. The plant will have a stippling, discolored flecking or silvering of the leaf surface. Thrips can spread many diseases from plant to plant. Burpee Recommends: Many thrips may be repelled by sheets of aluminum foil spread between rows of plants. Remove weeds from the bed and remove debris from the bed after frost. Check with your Cooperative Extension Service for pest controls.
Viola FAQs
Are violas edible? Yes they have a mild minty taste and may be eaten fresh as a garnish or candied and used on the top of cakes.
Why do my violas stop blooming in the summer? Violas are cool season annuals and hot weather will cause the flowers to fade and the plants to die out.
Are violas annual or perennial? Violas are perennial, but die out in the heat of summer. Many people grow them as annuals, replacing them every year. You can grow them for spring bloom or fall bloom or both, if you can keep them alive during the summer.
Should violas be deadheaded? Yes removing the spent blooms will keep the plant from setting seeds and will continue to bloom until the summer heat.
When do violas bloom? Pansies bloom in the fall and in spring into early summer when the weather is cool.