With ruffled, trumpet-shaped flowers in vibrant displays of burgundy, red, pink, white or purple, it's little wonder that gloxinia is a houseplant favourite. Dressed in their finery, some gloxinia display solid-coloured flowers while others have petals rimmed in white like lace and still others sport throats of contrasting colours. A relative of the African violet, gloxinia (Sinningia speciosa spp.) are cared for very similarly. Their ability to continue blooming season after season, however, varies depending on if they were grown from a tuber or a seed.
Repot a new gloxinia if the pot is small for the plant, and feel free to repot as necessary during your gloxinia's life. Loosen the soil surrounding the plant gently, then transfer to a slightly larger clay pot. Use a lightweight potting soil high in organic content. Potting soil for African violets works well.
Place your gloxinia in a brightly lit area, but not in full sunlight, which may burn the gloxinia's furry-textured leaves. Consider an eastern or western-facing window, or supplement weak lighting with artificial lights.
Maintain the room at warm but comfortable temperatures, avoiding areas with extremely hot or cold drafts that may shock the plant. As a rule of thumb, if you enjoy the temperature, your gloxinia probably will too. Temperatures of around 18.3 degrees C at night and 21.1 to 23.8 degrees C at most during the day are ideal.
Water your gloxinia frequently while it is actively growing, perhaps a couple of times a week. Stick your finger into the soil surrounding your gloxinia to check the moisture if you are unsure. If the dirt feels dry when you have the entire tip of your finger inserted, your gloxinia needs water.
Pour water -- preferably rainwater or water without minerals -- into the saucer underneath the plant, or on the soil around the plant. Never water the leaves or plant base to prevent burns and rot. If you allow your gloxinia to become too dry and the plant begins to wilt, place the pot into a tub full of room temperature water and allow it to soak for 30 minutes to an hour.
Keep a high-moisture environment around your gloxinia if possible. Run a room humidifier or place your gloxinia on a pebble tray. Cover a tray with small pebbles and pour a small amount of water on top -- enough to wet the tray and rocks, but not enough to cover the rocks, which would cause the plant to sit in water. This will add trace moisture in the air surrounding the plant. Don't
mist your gloxinia, which may cause damage to the foliage.
Apply a fertiliser high in phosphorous but low in nitrogen, suggests North Dakota State University. A 10-30-10 formula slightly diluted, applied every week to two week during the growing and blooming season, works well. Follow product instructions during application.
Pick off dead leaves and flowers as they occur. Deadheading a plant -- the term for pinching off the old flowers -- encourages it to continue blooming. Your gloxinia should bloom for six ti eight weeks.
Watch for a slowing of blooms and a sign that the leaves are beginning to dry out and turn yellow. This signals your gloxinia wants to enter dormancy. Generally, this lasts from October or November until February.
Place the dormant gloxinia in a cool, dry place such as a basement, garage or unused room; temperatures of about 12.7 to 15.5 degrees C are ideal, but do not allow it to go below 4.44 degrees C. Do not water or fertilise during the time it is in dormancy.
Transfer your gloxinia to a new pot in the spring, replenishing the soil, for best results. Place it back in its growing environment, pinching off the first bloom or two that tries to blossom to encourage a healthy, vigorous blooming and growth cycle again.
Traditionally, gloxinias were all cultivated from tuberous roots called tubers. Newer hybrids are often grown from seed instead. While producing better blooms, the new hybrids may have difficulty blooming after dormancy. Many people throw these plants out at the end of the season and start fresh the next spring. If planting a tuber, either after dormancy or upon purchase, plant it in the soil with the top -- typically the end that is dish-shaped -- pointing up and almost at surface level. If you are unable to tell which end is the top, plant it on its side and let mother nature decide which end is up.