Now that I know most gesneriads don't like direct sunlight, I move them around at the outer edges of my fluorescent grow-lights until I find a place where they seem happy. Of course, I could just raise those lights, but the orchids probably wouldn't like that.
If you are growing only gesneriads under your fluorescents, though, you can just keep adjusting the space between them and the bulbs until they seem happy. (Hint: If they look like they are shrinking under the glare, they are getting too much light. If they have to reach for it, they aren't getting enough.)
Most types will also grow on warm windowsills that receive bright light but no direct sun. If all your sills are sunny, you can just add a sheer white curtain between the glass and your plants. The most popular gesneriad is, of course, the ubiquitous African violet (Saintpaulia). I recently picked up a striking double type for an aunt who lives in a nursing home--and hinted strongly to her that I could always take it home with me, if it got in her way after it was done blooming!
Of course, it would be easy enough for me to just snip off a leaf and start my own, gesneriads being among the easiest plants to propagate. You can root African violets leaves by covering a water-filled baby food jar with plastic wrap or foil, poking holes in that covering with a pencil, and inserting the stems of the leaves through the holes. That way, the stems should dangle in the water, while the leaves themselves remain above it.
Gesneriads work so well as houseplants because they can get by on the lower levels of light indoors during the winter, and they also bask in the warm temperatures at which we keep our thermostats. About the only thing they don't like about our homes is the low humidity, which can be supplemented with careful misting.
I say "careful misting" because most gesneriads have fuzzy leaves which can rot if they get too wet. Cold water may also cause spots on those leaves. I would recommend using rainwater or spring water that has been allowed to sit until it is at room temperature. I generally spray it into the air over the plants too, rather than directly at them.
Don't limit yourself to African violets, however, as there are many other species in this easy-going family. One of my favorites, streptocarpus, I've mentioned in previous articles. My plants will do well on a table on our south-facing porch for most of the summer, due to wide overhanging eaves that block much of the sunlight. But, in the fall, the sun drops low enough in the sky to begin reaching under those eaves again--and the poor things start to cook. Fortunately, that's also the time when I take them back indoors and put them under the fluorescent grow lights in the basement. In my experience, streptocarpus prefers slightly cooler temperatures than most gesneriads do.
I've also grown gloxinias (Sinningias) from seed. As none of them seemed to produce the profuse bloom of the florist's types, however, I would probably have been better off purchasing bulbs.
Gesneriads that grow from bulbs generally require a resting period before they can be brought into bloom again. I have a species type of Sinningia (possibly S. eumorpha), which I allow to die down over summer and start up again in the fall. It will start sprouting before I even begin watering it again, which is a sign that it's ready to take off.
Be sure to label your pots, however, as I lose many of my bulbous plants simply because I forget what I did with the bulbs. I've learned to sift through the old dirt in an empty pot before I throw that dirt out--to see if there might be any hidden treasures in there.
Fortunately, I have an older gardening friend who is into gesneriads and frequently supplies me with new types, tactfully not inquiring what happened to the last ones! She gave me a whole pot of Chirita tamiana, pictured in the thumbnail, which blooms off and on for most of the year.
Like African violets, it gets leggy after a while, though. So I recently cut most of the stalks back drastically, leaving a couple gangly ones in case the pruning didn't work. The cut-back ones do seem to be putting out new leaves, so I'll probably chop back the others now too.
My friend is also into mini-sinningias which, because they need very high humidity, do best in terrariums. Other well-known gesneriads include the flame violet (Episcia), goldfish plants (Columnea and Nematanthus), hot water plant (Achimenes), and lipstick plant (Aeschynanthes).
There is obviously a type to suit all tastes--and almost all of them bloom enthusiastically under the right conditions. Since I seem to have picked mostly my purple-flowering plants for this article, I should point out that gesneriads do come in other colors as well. In fact, reds and oranges are pretty prominent.
Although I would like to report that I am now much better at all gesneriads, my successes remain spotty--with some doing well for me and some doing bupkis. So please take a lesson from me and don't give up on all members of this family just because you can't grow some of them. That African violet, for example, will probably be better off with my aunt than with me, no matter how sunny and dry her windowsill may be. But it was such a pretty one. . .