Viola, Perennial Growing Instructions
Grow perennial violas in full sun (at least 6 to 8 hours each day) or partial shade. Most varieties can grow quite well in shade, but don’t bloom as profusely. Water perennial violas enough to keep the soil moist, but not wet. Though these spring-flowering plants can tolerate some drought, they look better — and bloom better — with regular watering.
If you have average or good soil, you don’t need to fertilize perennial violas. You can fertilize if you wish, however — using any general-purpose garden fertilizer. Follow the directions on the product packaging. Topdressing your soil with compost each year will also help perennial violas to thrive.
Because violas are cool-weather-loving early-spring flowers, a layer of mulch over the soil around them can keep them happy and blooming later into the spring or early summer. A 2- to 3-inch-deep layer of mulch helps keep the soil cool and moist.
Perennial violas don’t require regular pruning, but you can cut the plants back in summer once hot weather sets in and stresses the plants.