Place African Violets in an east, west or north window, unless you are in the north and then a southern window in the winter is needed for blooming. See how, in one picture, the leaves are upright instead of laying flat? That is how African Violets respond when they are receiving too little light. If yours do that, give them more light.
The consensus is that African Violets soil must be kept moist. But I find mine do best when I thoroughly soak them, then let the top half inch or so of soil dry out. Many people use wicks to water them, or place them in a saucer and water them from the bottom only. The leaves do not like cold water or to be wet for any length of time, brown spots will occur where cold water hits them. If the pot is clay, the leaves that rest on the edge of the clay pot will die, however the plant itself will be fine.
African Violets actually like smaller pots than these are in currently. The pot should be one third of the diameter of the crown of the plant. They are in flower about nine months of the year provided they have enough sunlight. African Violets can get as large as 9″ in diameter.
African Violets do not like to be cold. Keep them above 60′ F and use warm water to water them.
It is very easy to propagate African Violets. Cut off a leave and leave the stem as long as you can. Put the stem in water or very damp soil. Make sure the leave part is not touching the water, prop it up with toothpicks if need be. When you see new growth treat it as you do your other violets.
If new leaves are stunted and curled you likely have cyclamen mites. Usually you can not save the plant, only take it away so as to not infect your other plants. You might try an insecticide.
Symptoms: Galls ( knots ) form on roots.
Treatment: Not much unfortunately start a new plant from leaf cuttings.
Symptoms: Older leaves drop and as crown rot progresses younger leaves start to drop as well. Stems are water soaked and weak. Roots become brown and die.
Cause: over watering
Treatment: Sometimes fungicides can help. They can be found at your local nursery. Also get the plant out of the wet soil and into fresh, sterile soil. It is organisms that actually do the damage.
Symptoms: Small spots appear on leaves and stems. The spots will enlarge, often quickly covering the entire leaf. Flowers look faded. A close look might show gray fungus.
Treatment: none – remove infected plants before the blight can spread to your other plants.
Symptoms: White filaments grow on leaves, stems, flowers, they will look like powder. It might only effect flowers.
Treatment: Use a fungicide available at your local nursery.
Symptoms: Rust colored spots appear where stem touches pot or soil. The stem and leaf collapse.
Cause: Too much salt accumulation in soil. This means too much fertilizer.
Treatment: Repot in a fresh pot with fresh soil and go easy on the fertilizers.
Symptoms: Rings appear on leaf surface, they might be white, yellow, or brown. Leaves affected eventually die.
Cause: Cold water touching the leaves
Treatment: Use warm water to water African Violets.
In the winter soil mealy bugs can be a problem for African violets.
The African violets get less light, the soil stays wet for longer times and it’s chilly by those windows creating conditions for soil bacteria and bugs to grow and attack.
The plants begin by wilting and the leaves appear to be thinner. This can mean root rot or soil mealy bugs are attacking your plant. Either way the best course of action is to repot your plant. It is the bacteria in the soil not the water that rots the roots. So either the bacteria or mealy bugs need to go.
Unpot the plant and check for mealy bugs, you’ll see little white spots in the soil at the bottom of the pot if you have them. If not it is bacteria that is the problem. When you unpot your plant gently remove all the soil from the roots, cut off damaged roots and rinse the roots thoroughly but gently in running water.
If when you unpot your plant you find the roots are short and all near to the surface that means you’ve been over watering your violet.
Buy some fresh soil at your local nursery and run your pot through the dishwasher if you wish to reuse it.
And remember as long as you have one healthy leaf you can root you have not lost your African violet.