Growing Gesneriads: It Is Time To Go Beyond Grandma’s African Violet

Though long overshadowed by the most popular member of the Gesneriaceae family, the African-violet, other lesser-known members are now coming into their own.

Two gesneriads, the colorful gloxinia, and episcia (flame violets), have already become popular.

Blooming GesneriadsPin

Many indoor gardeners who are experts at raising African violets want to know more about its less celebrated cousins.

Since the Gesneriaceae is such a large family—including 85 genera and about 1,100 species—I will only discuss some outstanding plants.

Gesneriads grow from the following:

  • Fibrous roots
  • Tubers
  • Propagules (scaly root stolons)
  • Woody rootstocks
  • Seeds

The majority of them are warm house subjects and, if given humidity will thrive in home temperatures of 70° to 75° degrees Fahrenheit.

Ideal Soil Formula For Gesneriads

Except for some climbers, they all require soil suitable for growing African violets.

The mixture should be porous so roots can easily penetrate it.

Pots must have good drainage. A heavy wet soil will not allow sufficient aeration, and the plants become prey for pests and diseases. 

A general soil formula consists of equal parts of the following:

  • garden loam
  • peat moss
  • leafmold
  • sand

Proper Gesneriads Seeding

To get some gesneriads of your own, buy tubers, rootstocks, or seeds from a grower who specializes in unusual house plants.

Tubers and rootstocks are usually started in February and March. This is also a good time to start seeds.

Here are the following tips to remember:

  • Water from the top or bottom with room-temperature water.
  • Make sure the soil is moistened all the way through.
  • Do not water again until the topsoil feels dry.
  • If you spill water on the hairy leaves, move the plants out of the sun until dry. This will prevent the spotting of the leaves.
  • Increase the humidity by setting plants on saucers of moistened sand or by plunging the potted plant into a larger pot lined with moist sphagnum moss.

Gesneriads Varieties

Most of the hairy-leaved gesneriads have foliage of such brilliance and beautiful contour that they would be worth growing for these qualities alone.

But good growers get added dividends in flowers of amazing forms and colors.

Rechsteineria Cardinalis

Rechsteineria cardinalis, often listed by the grower as Gesneria Cardinalis, is to my mind one of the most satisfying of the gesneriads.

This plant grows from a solid tuber about the color of a sweet potato.

Tubers may be started any time after the first of the year.

They can be pushed into active growth in moist vermiculite, sand, or sphagnum moss and later transferred to 4” inch pots.

Here are the following steps to do:

  • Plant the tuber in a 4” inch pot containing at least an inch of drainage material (broken pots or gravel) and the preferred growing mixture.
  • The round side goes into the soil, but not deeply. You should be able to see the top of the tuber protruding slightly from the soil.
  • Give the soil a good soaking with warm water and set the planting in a south window.

Rechsteinerias will grow and flower in the northeast or east window but can grow tall and need staking.

Their rich emerald green foliage is outstanding. Individual leaves are Nature’s own heart-shaped valentines.

The bright scarlet tubular flowers are borne about 3 to 4 months after planting, continuing for 6 weeks to 2 months.

The foliage stays fresh and lovely throughout the summer.

In August, these plants are ready for a rest.

They seldom drop their leaves but older foliage withers and browns at the leaf tips.

I cut off the old stalk about the 1st of August, set the plant away from the strong light, and cease watering.

Some tubers are stubborn about resting.

If new shoots appear in less than a month, bring the plant into the light to resume growth.

Occasionally, such a plant will bloom at Christmas and its coloring makes it an especially appropriate flower for that season.

Rechsteinerias can be propagated by the following:

  • leaf or stem cuttings rooted in water, sand, or vermiculite
  • flowered within a year from seed.

Smithiantha (Nagelia)

Smithiantha, better known as nagelia, is a prize winner in any houseplant collection.

The richly colored foliage and clusters of bell-like flowers make it a real eye-catcher.

Their natural growing season (though sometimes variable) begins in September.

Propagules can be started into growth in a small flat of moistened sand or another medium, or they can be planted directly into pots.

I like to start tubers in sphagnum moss, and when they show about an inch of growth, transplant 2 or 3 of them, with some moss attached, to a 5” inch pot.

If the moss is left on, I find they store better and there is less danger of losing the propagules.

East or tempered south light suits these plants.

Under ideal conditions, they would bloom 3 to 4 months after planting.

In a home, it is not unusual for them to wait 6 months before favoring you with flowers.

While you are awaiting flowers, you can enjoy the beautifully textured and patterned foliage.

Smithiantha Cinnabarina

The leaves on Smithiantha cinnabarina are plum-colored and covered with dark red hairs.

They remind me of red plush, and I find them exciting companion plants for white African violets or gloxinias.

The flowers on this plant are lighter red than the foliage, and the inside of the throat is creamy-white speckled red.

Smithiantha Zebrina

Smithiantha zebrina has more flexible leaves than Smithiantha cinnabarina, and they are green patterned with red.

The red and yellow-spotted flowers hang in graceful racemes.

After blooming has ceased, the plant should be kept watered until the leaves curl and dry.

When this happens, the plant should be given a rest and taken to the basement or a dark closet.

If the topsoil is sprinkled once a week, you will have firm propagules to work with for the next season’s bloom.

Whenever you note growth, do the following:

  • Turn the soil out of the pot.
  • Divide the propagules.

You will be surprised at the increase!

To start into growth, handle them as recommended above.

Propagation Of Gesneriad Varieties

If you have the urge to propagate a great many of these plants, do so by doing the following:

  • Break the propagule into individual scales.
  • Set the scales in moist sand, vermiculite, or sphagnum moss.
  • Shift when they are 2 months old.

These plants will be small, and 10 or 12 can be grown in a 4” inch pot of soil.

Smithianthas can also be grown from seed.

When growing from either scales or seeds, it takes about 2 years for plants to flower in the window garden.

Chirita Hamosa

Chirita hamosa is a pretty gesneriad you will enjoy for its unique manner of growth, and of course, for its dainty blue-edge white flowers.

The chartreuse leaves are covered with glistening silver hairs and the stern is as translucent as that of impatiens.

It is an upright plant growing to about 18” inches.

This plant is treated as an annual and is generally grown from leaf or stem cuttings started in water or moist sand.

Chirita will flower in 7 to 9 months from either cuttings or seeds.

The foliage color stays fresher when grown in an east or northeast window.

Rechsteineria Macropoda

Rechsteineria macropoda is a comparative newcomer to American gesneriad collectors. The American Gloxinia Society made seeds of this charming gesneriad available in 1951.

It took to American window gardens like a duck to water!

The plants bloomed when about a year old, and the tubers were fatter than those of any other-year-old gesneria seedling.

Remember these tips to ensure good planting:

  • A 4” or 5” inches pot is about right for a 1 ½” to 2” inches tuber.
  • After planting, they should be watered thoroughly and set in an east or south window.

The leaves are such a dark green that they appear almost black.

The tubular 1 ½” to 2” inch flowers are brilliant orange flecked inside with dark red.

Because these plants are still rather rare, many of us who grew them, hand-pollinated the flowers to increase our seed supply.

This gesneriad flowers in later February or March and can be set aside to rest as soon as leaves lose their vitality.

One commercial grower told me that some of his rechsteineria tubers sent up flower scapes without the benefit of foliage at Christmas.

After the foliage appeared, another scape of bloom pushed through.

Rechsteinerias are propagated by the following:

  • leaves
  • stem cuttings
  • seeds

While I have had excellent success rooting stem cuttings, I have not been able to get individual leaves to root.

Columnea Crassifolia

Another newcomer for the gesneriad collector is Columnea crassifolia, which was discovered in Guatemala in 1942.

Plants are available to the public for the first time this year.

This year, add some of these refreshingly different plants to your window garden.

You’ll be glad you did when a visitor singles them out and asks, “What are those beautiful plants?”