African violets originate from the tropical forests of East Africa. African violets like light, but not too much direct sunlight, which can dry out the plants and damage the leaves. I grow mine on a kitchen window sill that faces northwest. In summer they get around two to three hours of direct sunshine in the late afternoon, but little direct sunlight in winter. This seems to suit them fine. A window sill facing northeast would work just as well. If you do put them on a south facing window sill, pull down the blinds or draw the curtains during the hottest hours of the day to shield them from the sun. Plants will normally grow well on a window sill facing due north, but may not flower so profusely, you may need to install african violet grow lights for them to flourish.
In a greenhouse, avoid a hot south facing area. Larger plants can be put behind your violets in order to block out direct sunlight. Use shades to further reduce the exposure to direct sunlight.
Plants that are on a window sill need to be rotated regularly, so that they do not bend too much towards the light. Rotate a quarter turn clockwise (or conter-clockwise, but stick to the same direction) when you water.
Too little light is also bad. African violets will not thrive far from a window (they may do fine on nearby furniture units). Normal domestic lighting won’t provide enough light for them. If you want to grow these plants indoors, but do not have a suitable window, you will need to use specialist plant lighting. Use lights that emit in both the red and blue regions of the spectrum. Follow the instructions given with the african violet grow lights. The plants must get plenty of light, without being scorched by heat. Make sure the lighting is on a timer, so that it goes off at night. Violets need to “sleep,” for eight hours, just as we do, in order to bloom well.
African violets like warmth. The temperature should be kept between 60˚F and 85˚F. They tend to do better when windows are double-pane, so they don’t get too cold during winter nights. Avoid cold draughts. Sometimes an unfortunate African violet is left in an unheated spare room. Such plants rarely survive where winters are cold.
Plants are sometimes bought for the office, school, church, or other institutional buildings. They can thrive, provided they have the right conditions. Remember that the heating in such buildings may be switched off, or turned down to a minimum, when they are not in use. Your plants may not survive.
If a room becomes too hot and you do not have air conditioning, try taking the plants down to a cool cellar during the hottest part of the day. If all else fails, put them in the bathroom to cool down.
African violets like high humidity. They often do well on kitchen or bathroom window sills. In living rooms or bedrooms the humidity may be rather low. Air conditioning may reduce humidity. One way around this is to stand the pots on a low container full of pebbles. Fill the lower container with water, making sure the level is well below the bottom of the pot. The water from the lower container will provide a humid environment, without causing the pot to be water-logged. If a room is very dry, the plants can be lightly sprayed with warm water to keep them moist. Gently wipe any water off the leaves immediately after spraying. Never spray with water when the sun is shining on the plants, since it can scorch the leaves.
African violets can be taken outside during the summer months. Place in a shady position. Remember, these are forest plants. They can look good either planted under trees, or kept in their pots and placed on garden furniture on the shady side of a patio. If you take your plants out of their pots and put them in the soil, remember that they like a slightly acidic, well-drained soil. If you have very alkaline soil (basic soil), or heavy poorly-drained soil, they are best kept in their pots.
They may be more prone to attack by pests when outside. The danger is that these pests may be taken indoors when you take the plants back in. It is probably safer just to take spare plants outside, and leave them to die off in the fall. If you grow African violets from seed, you may end up with a lot of surplus plants, so they can be used for an outdoor display.