Viola is an annual flower and a member of the violet family. Cold hardy as far north as USDA Plant Hardiness Zone 4, violas reach 8 inches tall in full sun to partial shade. Viola blooms best when the weather is cool. Clip its sweet-scented blooms for small flower arrangements to enjoy their scent indoors. Viola self-seeds; watch for its petite blooms to appear in unexpected places, such as the lawn or a crack in the sidewalk.
Till the soil where the viola flowers will be planted, working down at least 8 inches for optimal root penetration as the plant grows.
Moisten the soil and scatter seeds across the soil. Barely cover the seeds with soil. Keep the soil moist. When the sprouts are about 2 inches tall, gently pull out the weaker sprouts. If planting seedlings or plugs, which are seedlings that come six to nine per pack, space them 6 to 10 inches apart.
Apply 1 to 2 inches of mulch, such as wood chips, over the disturbed soil and about 1 inch away from the stem of the plants. Mulch retains moisture and blocks weed growth.
Water every seven to 10 days if there is no rainfall.
Apply a water soluble, all-purpose flower fertilizer according to the manufacturer's instructions, which may be twice per month.
Cut the plants back to just above ground level after they slow or stop blooming, usually with the heat of summer. They may re-grow and bloom again.