Gesneriad refers to a family of plants, mostly tropical, that includes African violets. Most Southwest gardeners like to grow a few houseplants to get us through the off-season, when it is too cold — or hot — outside for our garden plants and us!
With gesneriads, you can test your skills at reading clues plants give you and even easily propagate, producing new plants for your home or to give to friends and family.
Types of Gesneriads
There are thousands of species of gesneriads, including African violets. These plants have been discovered in areas of Africa, Asia, and Central and South America, often in tropical areas. And once hybridizers get involved, you can find thousands more varieties that cross favorite characteristics of one gesneriad with those of another (for example, variegated foliage plus double flowers).
No matter how new plants come about, rest assured there is something for everyone. These are some fascinating and fun plants to grow. Some are grown mostly for their interesting leaves, and others for the stunning flowers. There are three classes of gesneriads:
- Fibrous rooted. Most gesneriads have thin groups of fibrous roots, which means their soil should never dry completely. African violets are among the fibrous types.
- Tuberous plants are similar to root crops; they have a bulb or similar tubular part that stores water and nutrients underground to help the plants survive dry periods. They can go dormant, so it helps to know if your gesneriad is tuberous (otherwise, you might think you killed the plant!)
- Rhizamatous gesneriads also have underground storage, but close to the soil level. The rhizomes are scaly and can even emerge above ground. Rhizamatous plants also undergo a period of dormancy.
How to Care for Gesneriads
As with any plant, you can get lots of advice, sometimes conflicting! So, your first step is to look up your plant on a reputable site for gesneriads and African violets. You can determine its type or root structure, and usually find care instructions there or from the commercial hybridizer. Here are a few general tips for gesneriads:
Gesneriads make great houseplants, thriving in typical indoor temperatures of 65 to 75 degrees F. They often do best if there is about a 10-degree drop to nighttime temperatures.
You can water African violets and other gesneriads from the top, being careful to use room temperature water and avoiding getting the leaves wet. The soil can stay moist, as long as extra water can run out the bottom of the pot. Some growers choose to water from the bottom with wicks or damp mats. Most gesneriads prefer moderate to high humidity.
Gesneriads need plenty of bright light to bloom and grow. Just avoid direct light in a window, which can burn the leaves. A curtain can filter light or you can place the plants on a north windowsill or away from the window in a bright spot. Daylight-type grow lights help plants thrive and bloom; be sure to look for instructions on length of time to keep the plants under lights and distance from the light source for best results.
Pots and Soil Mix
Most potting soils are too heavy for these plants that often are found on lime outcroppings. Lighten the mix with perlite and other porous materials to help improve drainage. Because the light soil lacks as many nutrients as some mixes, fertilize regularly at about one-eighth full strength. African violets like to have crowded roots, and should grow in a pot one-third the size of the plant.
Keep Gesneriads Happy
As with outdoor plants, blooming takes energy. If your plant is small, enjoy its first bloom or two and then remove some buds so the plant can focus on growing leaves. This will reward you with even more blooms later. Many gesneriads need to be repotted a few times a year to keep the soil and plant healthy. You can find good directions in the sources I’ve listed for pot size, type and how (and when) to repot.
Most of all, enjoy growing gesneriads! You’re likely to love it so much, you will want to join a local club of African violet and/or gesneriad enthusiasts; the clubs often advertise their meetings through Facebook, local garden centers or on national organization sites like the African Violet Society of America or The Gesneriad Society. You will get lots of tips and even free plant leaves as a member in most clubs.