Violas gave birth to pansies; pansies were developed from violas by plant breeders more than two hundred years ago. Their cultural requirements are virtually identical. Both like cool weather and most often stop producing blossoms when hot summer weather arrives. If you want to grow them indoors, you'll need artificial lighting and a cool room.
When you get your plants home from the garden center, pot them up, placing 3 to 4 plants in each 6-inch pot, using rich indoor potting soil.
Place the potted plants under the fluorescent lights. Position the lights so they are only a few inches above the tops of the plants. Provide a way to raise the lights as the plants grow, always keeping the lights 3 to 4 inches above the tops of the pansies and violas.
Grow in a cool room. Pansies and violas are spring-blooming flowers and prefer cool weather. If you're growing them indoors during the summer months, they will do much better if the room they're in is air conditioned.
Water well and often. These two spring beauties like a lot of water, so water when the surface of the soil feels dry to the touch. Don't allow the pots to sit in the standing water that drains out of the bottom of the pot. After the pots have a chance to drain excess water, remove the pots and empty the water from the saucers underneath.
Fertilize every other week with a liquid fertilizer, such as Miracle-Gro. Mix the fertilizer at half the strength recommended by the manufacturer.
Deadhead regularly. Cut off faded flowers regularly and promptly for continued bloom. Do not let seed heads form or your plants may stop producing flowers altogether.