Fill the pots with a lightweight, well-draining potting soil, leaving an inch of space at the top to accommodate soil-shift. Purchase one 5- or 6-inch plant pot per tuber.
Lay the tuber horizontally on top of the potting soil and cover the tuber with a light layer of soil.
Water the soil with a watering can until water seeps out of the bottom of the pot.
Place the potted tubers in a bright area but not in direct sunlight. A room with many windows is ideal.
Water the Gloxinia enough so its soil is evenly moist throughout its active growing time.
Fertilize Gloxinia with a balanced liquid fertilizer for houseplants once every two weeks as it grows. When the plant starts to bloom, increase the frequency to once a week. Cease fertilizing when the plant stops growing. Do not resume fertilizing until the following spring when the plant develops new growth.
Remove dead blooms and foliage from the plant as needed during the growing season.