Violas are easy to care for plants. There are over 500 different species. Most of the violas cultivated in gardens are grown as annuals or short-lived perennials. Many will self-seed and give you years of delight. Violas are primarily cool-season bloomers. They are perfect for starting and ending the season in colder climates and for bridging the seasons in warmer zones, where they can remain in bloom throughout the winter. So when to plant violas will depend on your climate. Viola flowers are edible and make unexpected garnishes and salad ingredients. They can also be candied, for a frosted effect or used to decorate cakes or other confections.
- Botanical Name: Violaceae is the genus with over 500 species
- Common Name: Sweet Violets, Johnny-Jump-Up, Garden Pansy, Pansy, Violets
- Plant Type: Annuals or short-lived perennials
- Mature Size: 6 to 10 inches tall, with 2 to 3 inch wide flowers
- Sun Exposure: Full sun
- Soil Type: Rich, moist, well-draining soil
- Soil pH: 5.4 to 5.8
- Bloom Time: Spring or Fall Bloom (or both)
- Flower Color: Light to deep violet, white, blue, yellow, and cream
- Hardiness Zones: 3 through 8
- Native Area: North America
How to Grow Violas
These are quite versatile plants, that work well both indoor and out. Viola’s size, compact habit, and long flowering period are perfect for containers. Trailing varieties are exquisite in hanging baskets and tumbling over the edge of containers and window boxes. They are standouts in bouquets and arrangements. You’ll notice the flower's scents more when they’re indoors.
Outdoors, the mounded plants make a lovely edging along a path or to define a garden border. Violas are as at home in woodland settings as they are filling crevices in rock walls. Combine them with other cool weather lovers like snapdragons, calendula, and Dianthus. Or tuck violas between spring flowering bulbs such as tulips and daffodils to fill the space as the bulbs fade.
Violas like full sun, but not the heat it brings. This isn’t a problem in cool spring temperatures, but when planting in the fall, make sure they get some shade during the hottest part of the afternoon. Mulch and water will help offset the stress of high temperature.
Water regularly, but allow the soil to dry out between waterings. They can tolerate some drought but will bloom best with regular watering.
Temperature and Humidity
Violas are some of the most cool-weather-loving early-spring flowers. They enjoy milder temperatures from 40 to 70 degrees Fahrenheit. With proper care, they can bloom all summer and most will bloom again in the fall.
Use a slow-release fertilizer into the soil. Fertilize in the spring and again in late summer to promote a fall bloom.
Violas are easy to start from seed. They are quite happy to self-seed all over your garden. If you would like to start your own indoors, the process is very straightforward.
Start seed about 4 to 6 weeks before transplanting. Violas can withstand some freezing temperatures, so cold climate gardeners can pick a transplant date that is about 4 weeks before your last expected frost date. Warm climate gardeners transplanting in the fall should start their seeds in mid-summer.
- Use a sterile potting mix.
- Moisten the mix and fill your flats or pots to about 1/4 inch below the top edge.
- Sprinkle 2 to 3 seeds in each cell or pot and cover lightly with the more moistened potting mix. Note: Violas need darkness to germinate, so cover the seeds completely.
- Set in a warm (65-70 degrees Fahrenheit) location and keep moist. On top of the refrigerator is a good spot. Seeds should begin to germinate in 10 to 14 days.
- Once the seeds sprout, move them to a sunny window or place under plant lights.
- When the first true leaves appear, you must thin the pot or cell to the strongest looking seeding by pinching or cutting the others at the soil line.
- At this point, a temperature of 55 to 60 degrees Fahrenheit is fine. You can also begin feeding your seedlings with any good balanced, water-soluble fertilizer.
Moving Your Viola Seedling Outdoors
When temperatures and weather permit transplanting outdoors, let the seedlings get adjusted to the change by hardening them off.
- Move the seedling to a shaded or protected location outdoors.
- Leave them outdoors for about 4 hours the first day and increase the time outside by 1 to 2 hours each day, slowly moving them into brighter light. The seedlings will tell you if they are unhappy by their appearance.
- Make sure the soil stays moist. Outdoor winds can dry pots quickly.
- Seedlings can be transplanted into the garden or containers after about 10 to 14 days of hardening. Just be sure the weather isn’t taking a downturn. Violas can withstand some frost, but not a late season snow storm.
Direct-seeding Violas into the Garden
Weather permitting, you can start viola seed directly in the garden.
- Good well-draining soil with organic matter is recommended.
- Loosen the soil in the planting area and moisten.
- Sprinkle the viola seed.
- Cover with about 1/4 soil and water well.
- Keep the seedbed moist.
- As seedlings develop, you must thin the plants to about 6-8 inches apart. Transplant excess seedlings.
Purchasing Bedding Viola Plants
Violas are often the first seedlings for sale in nurseries in spring in colder climates and at the end of the summer in warm areas.
- Look for healthy plants with lots of buds. Don’t be overly tempted by plants already in flower. They won’t transplant as easily, and you’ll have a longer season of bloom if the plants are only in the bud when purchased.
- Remove the viola plants from their cell packs by pushing up on the bottom of the container. Don’t grab the violas by their delicate stems.
- Gently loosen the soil around the roots and plant in the ground at the same level as they were in their cell pack.
Mounding violas should be spaced about 6 to 8 inches apart. Trailing or spreading varieties can be planted 10 to 12 inches apart. Violas begin blooming about 12 to 14 weeks after planting seeds. V. tricolor varieties bloom about two weeks earlier than V. cornuta. ‘Penny’ and ‘Sorbet’ will bloom 9 to 10 weeks from sowing.
Varieties of Violas
- Sweet Violets: Most of today’s violas are derived from Viola odorata, the Sweet Violet. You’ll stumble on them unexpectedly in fields and lawns and recognize them at once by their heady, sweet scent and deep violet color.
- Garden Violas: The violas cultivated for garden use are either:
- Viola tricolor/Johnny-Jump-Up: a self-seeding perennial with nickel-sized flowers marked with purple, yellow and white.
- Viola cornuta/Tufted or Horned Violets: spreading perennials with a rosette of leaves topped by 1 ½ inch flowers in a variety of colors with rays or lines in a deeper or contrasting shade. The plants can get 6 to 10 inches tall.
- Viola wittrockiana/Garden Pansy: a short-lived perennial with larger flowers. The plant grows about 8 inches tall and has 2 to 3 inches flowers that can be single colored or patterned. These are usually grown as annuals.
To promote blooming and extend the flowering period, remove or deadhead faded flowers by pinching off the blooms at the base of the flower stem. You can revive leggy or overgrown plants by cutting them back to about 3 to 4 inches tall. To avoid gray mold, don’t let your plants sit in cool, wet conditions. Make sure your violas get plenty of sunshine and have good air circulation. If you notice aphids, wash the plants off with a strong stream of water, or, for severe problems, treat with insecticidal soap.