Growing The Colorful Gloxinia Plant

The Gloxinia Flower! It is a triumph to plant thick, dry, brown, and barren-looking gloxinia tubers and watch them produce a luxuriant plant with layers of large, oval, velvety leaves topped with a crowning glory of immense flaring, tubular flowers in rich patterns and glowing colors. 

That’s what happens when you grow gloxinias, tuberous-rooted relatives of the African violet, and more correctly called Sinningia.

Blooming double Gloxinia plantPin
Flowers on a double Gloxinia plant

The Gloxinia Flower At Home In The Brazilian Rain Forest

At home in tropical Brazilian forests, Sinningia speciosa (Gloxinia) flower naturally in spring and summer, drop their leaves and go dormant during winter’s less favorable months. 

Because we can control indoor weather and today’s hybrids are bred for strength and fullest flowering, our new gloxinias often flower at intervals during most of the year. 

The Brazilian gloxinia seldom goes dormant. Others may rest for a few days or several months. And the tubers can be started into growth whenever they are available – online or from mail-order suppliers in all but the coldest winter or hottest summer months.

How To Grow Gloxinia Plants

Let’s look at the growth cycle of, perhaps, your first gloxinia tuber. It feels firm and lively. It’s neither dry and shriveled nor soft with rot.

The Soil and Potting Your Gloxinia 

If it’s a large-size tuber, you select a five-inch pot (preferably, a shallow bulb pan) and put a one-inch layer of gravel or broken pieces of the crock in the bottom. Now, add enough soil (the mixture recommended for growing African violets is acceptable) to fill the pot halfway.

Set in the tuber, cupped side up, and cover it completely with soil. The finished soil level should be about a half-inch below the pot rim.

Watering The Newly Planted Gloxinia Tuber

Moisten the soil and pot thoroughly by setting it in water nearly to the rim. When the top of the soil is shiny and moist, remove the pot and let it drain. 

Then, put it in a shaded warm (60° degree Fahrenheit minimum) spot protected from drafts. Bottom heat from a heating coil will speed up the rooting. Water only enough to keep the soil slightly moist until leaves begin to show at the top.

Light Your Gloxinia’s New Growing Location

Now, move the plant to its permanent growing quarters. This area should have a warm window where bright light or some sun will reach the plant but shaded against the very hot sun. 

Another option is the installation of fluorescent lights of sufficient intensity. In either case, if the indoor air is dry (and in winter, it usually is), increase humidity by setting the pots on, not in, a layer of sand or gravel in a water tray at least as large as the plant’s mature leaf spread.

Step up the watering schedule so that whenever you touch the soil, it always feels moist. But never so much that the roots are constantly soggy-wet.

Water Temperature

Room temperature water is the safest and won’t make white marks on the leaves. Every two or three weeks, water with a weak solution of soluble liquid houseplant fertilizer. 

Gloxinia Problems To Watch Out For

If the:

  • Stems begin to grow long
  • The plant gets lazy
  • Leaves curl under on the edge

The light is too dim, and your gloxinia may not flower freely.

Extra high humidity is called for if your gloxinia is mature and ready to flower and the buds drop without opening. You may need to enclose the plant in a polyethylene tent until flowering gets a good start.

The End Of The Gloxinia Flowering Season

When the last bud has opened and the last flower has faded, cut off the old stems and leaves and look for signs of new growth from the tuber. 

If you see the new leaves, continue watering and fertilizing. Repeat the complete process as long as new sprouts are produced after flowering. 

When growth stops, water the plant a little less each time until the soil is nearly dry. Then, store the tuber in the pot in warmth (50° to 60° degrees Fahrenheit) and dim light until it signals a new growth cycle by sending up tiny new leaves. 

Repot in fresh soil, and off you go again! The dormancy period can vary from a few days to several months. Water occasionally a resting tuber so it won’t dry up and die.

Fancy Hybrid Gloxinias

Among today’s fancy hybrid gloxinias, the most popular and most spectacular are the large-flowering types with trumpet-shaped blooms standing almost upright at the end of short stems. 

The throat flares out into a circle of overlapping petals. The basic gloxinia colors include – shades of blue, purple, pink, white, and red – which may be spattered, spotted, or contrastingly bordered. The throat is sometimes light, sometimes the same as the rest of the flower. 

These may be sold as named varieties, more often as groups of large flowering hybrids bearing the grower’s name. Another group of modern hybrids is the slipper-type gloxinias, with more slender flowers that nod from taller stems. And, of course, the fully double flowers.

When you buy tubers, note that the larger size gives you more, not larger, flowers, and the maximum tuber size varies according to variety.