For indoor gardeners who love a challenge, try African violets - often known as the queen of all houseplants.

These plants, which can be beautiful bloomers, do require a lot of specific care. However, the Web site for the African Violet Society of America Inc. at http://www.avsa.org has a ton of information on exactly how to maintain these sometimes persnickety houseplants.

The following is a list of basic care tips from the African Violet Society of America:

Watering: African violets need just enough water to keep the soil moist. Too much water will leave them susceptible to root rot and crown rot. It can also cause de-nitrification, a condition which prevents plants from getting the nitrogen they need.

The water should be room temperature, or as close as possible in temperature to the air around your plants. If the water is too cold, it chills the roots of the plant and causes the leaves to curl down.

Also, do not water the leaves. Try to water the soil directly. Watering the leaves causes them to turn yellow.

Grooming: Remove potting soil or other debris from the leaves. Use a soft bristled brush to remove dust or dirt. Remove spent blossoms and damaged leaves. These can encourage rot and spread to the healthy parts of the plant.

Light: The amount of light that an African violet receives is important for its health and overall performance. If an African violet does not get enough light, it will stop flowering and its leaves will begin to turn yellow. It is also likely that the African violet which is not getting enough light, will become rangy as it develops elongated leaves and stems.

If you have access to a light meter, the correct luminosity for African violets is 10,000 to 12,000 lux, or about 900 to 1,100 foot candles. The plants also need at least eight hours of darkness, each day, in order to bloom.

Temperature: African Violets thrive in an environment where the air temperature is about 70 degrees, does not dip below 60 degrees and doesn't rise above 80 degrees.

Fertilizer: Violet food is a fertilizer specifically labeled for African violets. A good violet food should have approximately equal amounts of the primary nutrients, nitrogen (N), phosphorus (P) and potassium (K).

Some fertilizers that have been labeled for African violets contain impurities that can be harmful to them. For example, when selecting a fertilizer suitable for African violets, make sure that it does not contain urea nitrogen.

It's also important to chose a violet food that is 100 percent water-soluble.

Be careful not to over-fertilize, which can cause leaves to become cracked or brittle, may produce lesions on the leaves and stems, could stifle an African violet's ability to absorb certain other elements, and can lead to droopy leaves, leaf tip burn and diminished flowering.