Viola cornuta. We loved this petite pansy as soon as it bloomed, and it bloomed in the first year, over a long period. Just 14 to 16 weeks after seeding, its small, very dark, and flat-faced flowers began to appear. With regular deadheading Back to Black just blooms and blooms. The foliar growth is vigorous, but the stature of the plants remains compact at about 15cm (6") tall. It would look great in containers or window boxes, but it takes on a wonderful appearance in mass plantings. The flowers are actually very deep purple, but so deep that they appear black from a few feet away. Each delicate flower is streaked in the centre by a brush of golden yellow. The edible flower petals look amazing scattered on ice cream. Sow in early spring for summer flowers, or as late as July for winter blooms. It's hardy in Zones 5 to 9.
Hardy annuals and perennials that are variously known as pansies, Johnny-Jump-Up, and Heartsease.
When I Get My Seedling Home
Keep seedlings under very bright light to prevent legginess. Artificial lights are ideal, but a bright (ideally, south-facing) room will work for the short term. You may have to pot on seedlings more than once before they go out to allow for root growth. This is done by transplanting them into a slightly larger container with enough additional soil to keep the container mostly full. Keep the soil moist by daily watering and allow for free drainage so the plants are never sitting water.
Do not transplant outside until daytime temperatures are steadily 10°C (50°F) or warmer. This may mean keeping seedlings indoors for up to a month. The plants should not require any fertilizer until transplant time. Space at 15-23cm (6-9″) in the garden.
Fertilize once or twice in early growth and provide a mulch around plants to keep roots cool as weather warms. Deadhead to prevent self-sowing, particularly with Johnny-Jump-Ups.