University of Illinois Extension

Growing Gloxinia

If your home needs some exciting color and texture among the dark, cold days of winter, there is a plant that can help, said Matt Kostelnick, U of I Extension horticulture educator.

“Gloxinia definitely deserves a chance in your home this winter,” said Kostelnick, who discovered the plant while an undergraduate studying horticulture. “It is a flowering houseplant with one of the most beautiful and unique flowers I’ve ever seen.”
When blooming, the Gloxinia displays beautiful, rich-colored, bell-shaped, velvet-like flowers of various vibrant colors that he terms “unbeatable.”

Gloxina“Hybridization has brought a wealth of colors, patterns, and double blooms,” he said. “The foliage of the Gloxinia plant is also unique, possessing large, fuzzy leaves.”

Gloxinias (Sinningia speciosa) are a close relative of African violets, both of which belong to the Gesneriaceae family, also known as Gesneriads.

“The leaves of Gloxinia easily give this away because like African violet leaves, they are pubescent--hairy--and feel very similar to the touch,” he said. “Many of the cultural requirements of Gloxinia are similar to African violets. And like African violet leaves, they are very sensitive to cold water and need to be watered properly to avoid leaf distortions.”

Gloxinias are often purchased in full-bloom from retail floral shops or can be purchased as tubers through mail order. Home gardeners can grow Gloxinias from the tubers in a four to six inch pot in a well-drained, artificial soil mix. Gloxinias can also be propagated by taking leaf cuttings, which is also how many African violets are propagated.

“Gloxinias need plenty of bright, indirect light, but respond negatively if they receive too much direct sunlight,” Kostelnick said. “Leaves stretch if light levels are too low. If necessary, use supplemental lighting.”

The plants are also sensitive when it comes to watering.
“They will definitely respond negatively if watered improperly,” he cautioned. “It is important not to over-water Gloxinias. Water them when the soil feels dry to the touch. You can also water the plant from below--sub-irrigation--by placing the pot in a saucer of water and removing it after about an hour.

“Sub-irrigating Gloxinias is a good idea because the crown of the plant is very sensitive to excessive moisture and is prone to rotting. Do not use cold water when irrigating. Be sure to use lukewarm water as Gloxinias are sensitive to cold water. Finally, keep water off of the leaves when watering.”

Moderate fertilizing with a general, well-balanced houseplant fertilizer also benefits Gloxinias. Fertilizer needs are highest when the plant is actively growing and when blooming heavily.

“When actively growing, Gloxinias do best in temperatures of about 70 degrees F and when in bloom prefer temperatures in the mid-60s. This is ideal for a home in the winter and spring months. Relatively high humidity also helps,” he said.

Amazing blooms are the hallmark of the Gloxinia plant. The plant blooms for about two months.

“Blooms are stunning and can reach up to five inches in diameter,” he noted. “After blooming, the Gloxinia plant and tuber enter a dormant stage. This happens when the plant stops sending out new blooms and leaves begin to die back.”

Kostelnick said the dormant stage is required for the plant and last about six to nine weeks.
“During this time, watering should be kept to a minimum and fertilizing should be stopped,” he said. “Think cool and dry conditions, similar to what most bulbs and tubers need during their resting period.

“After this dormant period, the tuber can be grown again to produce a new plant.”