It’s nice to have African violets, but it’s best to have healthy African violets. Although these succulent plants are easy to grow, their care is multi-faceted. This article will give you the basic steps needed to keep your African violet healthy and looking good, and will recommend where to read further details which will yield the best results.
Water the African violet when needed, early in the day, with water that has had at least 24 hours to "breathe."
Strictly avoid using soft water. Allow gases which are harmful to the plant evaporate from tap water. If you get a drop or more of water on the leaves, touch an absorbent paper towel to the drop to pick it up. Keep the plant out of the light until the leaves are completely dry to avoid the formation of spots on the leaves. Such tropical house plants as the African violet will use less water during winter months, so make sure to keep the soil moist without over watering the plant. See "How to Water an African Violet."
Groom the African violet each time you water it. Remove whatever is dying or that shouldn’t be there.
Remove dead leaves and spent blossoms to prevent the plant from wasting energy trying to revive them. Remove suckers, miniature plants that may form near the soil line but don’t start from the plant stem. They destroy the plant’s symmetry and make it less attractive.
Dust the leaves. Yes, dust them. Your plants gather as much dust as other surfaces in your home, but it’s more difficult to see on the hairy leaves of the African violet. Use a microfiber cloth, soft brush, or damp sponge to remove whatever debris has collected on the leaves. With your fingers or tweezers, remove any plant debris from the surface of the soil. See "How to Groom an African Violet."
Provide bright light, but not direct sunlight.
If the light can cast a strong shadow, it’s too bright. Select an east window if you have one. Northwest and northeast windows have worked well for me. If the light is always or seasonally too bright, filter it as needed through a sheer curtain or through partly open blinds. A window screen also cuts the intensity of light. See "How to Provide Light for an African Violet."
Provide supplemental light.
Evening artificial light-regular fluorescent and/or a grow light-is an important supplement during winter months. Position the lights 6 to 12 inches above the African violets. Less effective but still helpful, simply turn on an incandescent light on the table holding the violets to provide light and a bit of warmth. See "How to Provide Light for an African Violet."
Provide the correct ambient warmth and humidity.
Keep the room temperature around 70-80 degrees during the day and 60-69 degrees at night, and the humidity not less than 40% at all times. Humidity levels of 50-70% are best. Arrange African violets in groups to help raise their local humidity. You may need to increase their humidity further by interspersing small cups of water among them, or by placing them on top of stones in a large tray where you will water them all at once. Plants may dry out more rapidly in some locations in your home, so keep an eye on each area and treat them specifically: if the African violets in your study dry out the quickest, water and humidify them when needed, but do not use them as a schedule for watering and humidifying the African violets in your family and living rooms.
Trim a healthy leaf from an African violet: that plant and others nearby will grow more. A researcher for The African Violet Society of America (AVSA) explains that this type of trauma to an African violet triggers a warning signal: the plant emits a small amount of ethylene gas, to which nearby plants and other sections of the same plant respond by boosting up to 20% their rate of photosynthesis. As a result, larger leaves and more abundant blossoms are produced.
Remove blossoms early to encourage more vigorous blossoms to grow. If your African violet produces abundant foliage but does not bloom, AVSA suggests specific types of trauma to the roots that will promote vigorous blossom development: squeeze the pot, or pick it up and drop the plant and pot from a few inches of height. For neatness, slip the African violet pot into another container that will contain soil that may drop through drainage holes, and cover the soil under the leaves with plastic wrap before dropping.
Promote even growth.
Turn the plant a quarter turn each time you water it, to prevent the leaves from growing in one direction toward the light.
Keep the plant at about the level of the windowsill. If your plant stand is too short, the African violet’s leaves will become leggy as they reach toward the light.
Position the plant about a foot away from the window glass, and be sure to fill any sources of drafts with caulk or cover with tape. Both cold drafts and excessive heat are harmful to your African violet.
Rejuvenate the plant.
Repot occasionally to restore a nutrient rich soil or to bury the neck of an aging African violet so it can form more extensive roots. See "How to Rejuvenate an African Violet by Repotting."
Feed the African violet.
About one month after you repot or receive a new African violet, begin to use a water-soluble liquid fertilizer. When you shop for fertilizer, generally you will notice three numbers, each separated by a dash; e.g. 20-20-20, 14-12-14, 7-7-7; which indicate the percentages of the most critical ingredients: nitrogen, phosphate, and potash. Each of the strengths given in the example is too strong for the African violet. If you buy a 20-20-20 fertilizer, dilute it to be one fourth the strength. Even a 7-7-7 fertilizer specifically sold as African violet plant food should be cut to half strength. Trace amounts of other minerals will be present, but do not use a fertilizer that contains inexpensive urea nitrogen, which is a form of nitrogen but which stresses an African violet with root burn and makes it look poorly. Properly fertilize the plant each time you water it.
Prevent insect and pest damage.
Regularly examine the African violet for signs of such damage. A few changes that should be investigated (out of a multitude of other symptoms that can develop) are when leaves develop holes, scarring, become brittle, darken, or water-soaked; flowers develop brown spots, holes, a white or gray powder or spots, or become deformed; stems rot or swell. Go to Optimara.com (link provided below) for their tool to diagnose and treat African violet illnesses.
Keep the African violet’s leaves dry and empty the saucer 30 minutes after watering. Quarantine new plants and implements used on them, and wash your hands thoroughly after tending them. Sterilize by a 15-minute soaking in a 1:15 solution of bleach to water all implements, pots and saucers before repotting. See "How to Protect an African Violet from Insects and Pests."
Make more plants to increase your collection or to share with others.
Although this isn’t a strictly necessary step to grow healthy and beautiful African violets, you may find that some of your friends wish they were able to grow them as well. It’s easy to propagate any African violet by cutting one of its leaves and placing it in potting soil, and these new plants-along with correct instructions-make excellent and inexpensive gifts. See "How to Propagate an African Violet for a Gift."
When you provide the correct ambient warmth and humidity for your African violet, you also will feel comfortable.
Special grow lights are not necessary. If you want to provide supplemental (artificial) light, use an ordinary fluorescent tube: it’s sufficient and saves you money.
Especially in the winter, the air in your home is too dry for your African violet. Be diligent to provide and maintain the correct level of humidity!
Avoiding insects and pests is much easier than removing an infestation and treating the condition.
Some insects can be removed with a soapy water bath or spray; or by removing individual pests with a cotton-tipped swab saturated with alcohol.
When you give an African violet as a gift, print a copy of this series of articles to give-or e-mail the articles-to the recipient.
Never water an African violet in the evening or at night. The African violet will not be able to adequately process the water, and the excess will invite molds and fungi.
It takes about ten days before you can see any reaction of the African violet to a fertilizer. Overdo it with a too-strong African violet food and you will damage the appearance and health of your plant. New leaves will look "rusty" and the plant’s crown will develop too tightly. Chronic excess will kill the African violet.