Many kinds of gesneriads are very easy to grow while others can be challenging. This page contains some helpful hints and suggestions for getting started.
[This is the text of a small pamphlet distributed by The Gesneriad Society. A pdf version of the pamphlet is available at the bottom of this page.
The first step in gesneriad culture is to
provide bright but not scorching light. Inadequate light is the number one
cause of poor bloom and slow growth.
As a general rule, keep plants as close as
possible to an unshaded south (or east or west) window during winter. In
summer, try a south window with light shade, or an unshaded east window. Rotate
the plant regularly to promote even growth. Gesneriads can be grown outdoors in
warm weather; provide dappled light.
Symptoms of excessive light are sunburn, bleaching, leaves that bend down and hug the pot, and abnormally short stems.
Symptoms of inadequate light include poor growth and bloom, excessive stem elongation, and leaves that reach up towards the light.
Water regularly as long as the plant is actively growing. Most gesneriads do best if watered "evenly." This means that they should be watered fully (so that the soil is thoroughly wet and water runs out the bottom of the pot), and then not watered again until the soil begins to dry slightly (but is not yet desiccated and desert-like). Pour out any extra water in saucers; leaving plants standing in water will keep the roots too wet. Don't use "softened" water; it contains salt.
Let the plant tell you when to water; check the soil. Plants need water more often in hot dry weather, and less often in cool damp weather. As a rule of thumb, if the plant is dried out and needs water more than twice a week, it needs a slightly larger pot; if it is still wet after more than ten days without watering, it is probably over-potted.
Pots and Soil
Gesneriads do well in a light well-drained
soil mix. If the mix feels coarse and "clumpy" when wet, it is
probably OK. If it feels like mud, it is
probably not OK. Most growers use a commercial peat-perlite-vermiculite mix.
Re-potting every year or two can be
helpful. When you increase pot size, do it in the smallest possible step. Press
down only gently on the soil when repotting; excessive pressure compacts the
Most gesneriads will do best with a rather
small-looking pot, well-draining mix, and regular watering. Trying to reduce
watering frequency by using a large pot of soggy mix is a bad idea. It will
result in root rot. More gesneriads have been killed by overpotting than by
Gesneriads grown in home conditions generally do not need much fertilizer. As a rule of thumb, using any water-soluble fertilizer at about one-quarter (1/4) teaspoon per gallon is adequate. Fertilizing lightly with every watering is better than large doses sporadically applied. An occasional watering with plain water can help flush out accumulated salts.
Most gesneriads will do well at ordinary
house temperatures between 50F and 80F. Achimenes, Episcea and Nautilocalyx
should be kept at the warm end of this range. Streptocarpus do
better if they are kept cool in summer.
Good air movement is very helpful. It can reduce problems with overheating, and can reduce mildew problems in cool damp weather.
Windowsill growing usually works well. So do “light gardens"; many expert growers keep their plant collection under fluorescent lights in a cool basement.
The basic culture directions above are suitable for most of the commonly-grown gesneriads without a pronounced dormant season, including Alsobia, Aeschynanthus, Codonanthe, Columnea, Kohleria, and Nematanthus. Streptocarpus and Chirita can be grown similarly. (They grow slowly in winter but do not stop altogether. )
Plants that have pronounced dormant
seasons require some extra instructions. These plants have underground food
storage organs that enable them to survive a severe dry season in their native
habitat. The advantage to the grower is that if you neglect watering for a long
period, you get a second chance!
Achimenes, Eucodonia, Smithiantha,
Gloxinia. and Kohleria
grow from underground rhizomes that look rather like tiny pale pine cones.
Plant the rhizomes an inch or so below the surface after they sprout in the
spring. Begin watering gradually; once the plants start actively growing they
should not be allowed to dry out even briefly or they will go dormant again.
The plants can be put outside once the weather has warmed up. Achimenes dislike cold. They will bloom in mid to late summer. In the fall after they have finished blooming the leaves will begin to die. Reduce water and eventually stop entirely. The foliage will die, and the plants will form new rhizomes. The rhizomes can be harvested and stored in a cool, mostly dry (but not desiccated) storage location until spring.
Sinningia (including "Florist Gloxinia")
grow from tubers at the base of the stem. Grow them in pots only slightly
larger than the tuber, and provide very good light. The top of the tuber should
be close to or just above the surface.
When the plant decides to prepare for the
dry season, the foliage will begin to die back. At this point the grower must
reduce watering drastically until new growth appears. If the grower fails to
reduce water, the soil will become soggy when the plant is expecting dryness,
the tuber will rot, and the plant will be lost.
While the plant is dormant, it can be stored in any cool dry location. Once growth resumes, increase watering and return the plant to a favorable lighting position.
The micro-miniature species S. pusilla, S. concinna, and S. sp. 'Rio das Pedras' do well in terrariums under fluorescent lights. They seldom go dormant for long, if at all.
You can cause plants to branch by removing
the growing tip. This encourages lateral branching. Frequent pinching (every
couple of leaf nodes) can result in a much bushier and more attractive plant.
Shrubby or stalky plants are good candidates for this treatment.
Plants with long hanging stems should not be pinched except very near the base. The stems look more attractive if they hang as single long strands rather than splitting part way down.
Small delicate plants can be grown in terrariums. A terrarium can be a simple glass bowl with a cover, or as fancy as an expensive "doll house" of glass sheets, or as utilitarian as one of the omnipresent translucent plastic boxes. Use a very loose mix in a terrarium; some people favor 50% perlite and 50% chopped long-fiber sphagnum. Avoid placing a terrarium in direct sun; the temperature can rapidly get out of control. Add a small amount of water occasionally to make up for losses. Remember to use a weak fertilizer solution when adding water.
This list briefly describes the culture of the most popular genera. There are exceptions; don't be afraid to ask questions.
Achimenes are rhizomatous plants with large bright flowers. They are often grown as hanging basket plants outdoors in summer (keep them moist), and are dormant in winter.
Aeschynanthus are hanging or spreading plants with brilliant red or orange tubular flowers. They do well in hanging baskets in good light and are very tolerant of growing conditions.
Chirita look a little like thick-leaved African Violets with more tubular flowers. They tolerate low light and dry cool winters. Use a very small pot.
Columnea are hanging or spreading plants with brilliant red, yellow, or orange tubular or "hooded" flowers. They do well in hanging baskets; most like warmth.
Episcea are noted for their wide variety of leaf patterns. They prefer very warm temperature, lower light, and good humidity.
Kohleria tend to be tall, but the flowers are bright and have interesting patterns.
Nematanthus ("Goldfish Plant") are bushy or spreading. Most have bright orange flowers with a "belly" hanging below a tube.
Sinningia are mounded or tall plants in a range of sizes from thimble-growers to three-foot specimens. The flowers are often red, white, or purple. They grow from tubers and have a dormant period.
Strcptocarpus are good bloomers with large purple, pink, or white flowers. Keep them cool in summer for best results.
We have probably all seen people rooting "African Violet" leaves in a glass of water. You can start most gesneriads from stem or leaf cuttings. Place the cutting in water or in a little slightly moist (not soggy) soil mix in a plastic bag. The cutting should root within a couple weeks; it can then be taken out and potted in a small pot. Keep the newly-potted plant in a bag for a few days to allow the roots to develop further.
When removing any plant from a closed container for growing in the open, start by opening the container a tiny amount for the first few days; gradually open a little more each day, so the plant gradually becomes accustomed to the lower outside humidity.
Members of The Gesneriad Society are your
best source for information. You can find the society web pages at:
Another excellent resource is the book, How to know and grow gesneriads, from The Gesneriad Society. It is distributed free to new members.
Growing Streptocarpus for Show