The pansy, they are every bit as hardy, with happy blooms that resemble a monkey’s face growing on slender stems amid attractive green foliage. Violas make an early appearance in the flower bed, poking up their heads as soon as daytime temperatures reach about 15.6 degrees Celsius. Versatile little flowers, violas thrive in a bed, hanging basket, window box or patio container, and are lovely in small cut-flower arrangements.
Plant violas by seed in partial shade or full sunlight during summer or autumn. Soil should be prepared in advance by cultivating to a depth of 6 to 8 inches. Work in 2 to 3 inches of compost or manure to enrich the soil and improve drainage. Scatter the seeds on the ground and cover them with a light dusting of soil. If you prefer, plant viola bedding plants, available at garden centres or nurseries, in spring, after all danger of frost has passed.
Water violas in the morning or early afternoon so excess water will evaporate before evening. Water at ground level and avoid watering the foliage any more than necessary. Violas are drought-tolerant, but will benefit from about 1 inch of water every week during spring and summer.
Spread 1 to 2 inches of organic mulch around the violas, but be careful not to cover the plant. Shredded bark or grass clippings will retain moisture, keep the roots cool during hot weather and help to control weeds.
Pinch off wilted viola blooms so the plant will continue to bloom as long as possible. Cut the flowers for bouquets as often as desired.
source ; flowercouncil / ehow