11 Common Pests and Diseases That Love African Violets
African Violets can succumb to many different issues, depending on their environment. These delicate plants should be cared for to avoid common pest and disease infestation. In this article, gardening expert Liessa Bowen looks at the most common diseases and pests that you may come across when growing African Violets both indoors and outdoors.
When you first purchased an African violet, it was probably in full bloom and looked fantastic. But what if, over time, your once-healthy African violet starts to look droopy, damaged, or deformed? Many possible culprits could cause problems for African violet owners, including insect pests and fungal diseases.
The best way to stop the spread of pests and diseases is to prevent them from happening in the first place. When you purchase a new plant, always inspect it carefully for signs of pests or poor health. When you bring a new plant home to your collection, isolate it for a few weeks, ideally in a separate room from the rest of your houseplants, to ensure it has no insect pests that could easily spread from one plant to another.
One of the best ways to keep pests and diseases away is to provide the best care you can for your plants. African violets have specific growing conditions where they will enjoy optimum health, and the closer you get to these ideal conditions, the healthier your plants will be.
- Light – 12 hours of bright but indirect sunlight each day
- Water – Allow soil to dry slightly between waterings, water only after the soil has dried
- Temperature – Warm, between 65°F and 80°F, ideally around 70°F
- Soil – Loose, light, well-drained, with plenty of organic matter
- Fertilizer – Fertilize regularly with African violet plant food
A well-cared-for African violet is a beautiful plant to enjoy and grow. They stay relatively compact, with neat rosettes of soft, fuzzy leaves, and they can bloom throughout the year with showy, colorful flowers.
If you ever notice insects feeding on your African violet, or if you see any signs of illness, act quickly. The sooner you can correctly identify the problem, the sooner you can help your violet back to peak health. Let’s now take a look at 11 common pests and diseases you may encounter with your African violet plants.
There are several diseases that can infect African violets. Look for drooping leaves, mushy leaves and stems, slowed growth, moldy spots, or visible deformities. At the first sign of any plant distress or illness, isolate your plant and try to identify the problem.
Root rot is one of the most common problems that African violet owners may experience. As the name implies, root rot begins with the roots but can spread to the stems, leaves, and flowers. If not corrected promptly, root rot will ultimately kill your plant.
Root rot is caused by a combination of wet soil, saturated roots, and a fungus that causes the plant to rot. The most common causes of saturated soil are overwatering, poorly draining soil, and using a pot with little or no drainage.
Even though root rot begins with the roots, wilting leaves are the first symptom you are likely to notice. If you have any reason to believe that your African violet has been sitting in wet soil, and then you notice limp or wilting leaves, there is a very good chance your plant has root rot.
More advanced stages or root rot will be indicated by mushy stems and leaves, and finally, the entire crown of the plant becomes mushy and jelly-like.
Don’t overwater your African violet. Since damp soil conditions can easily lead to root rot, be very careful not to add more water if your plant doesn’t need it. Feel the soil’s surface with your fingertip. If the soil feels completely dry, it’s usually a good time to water.
If it feels damp, hold off a while longer. You can also pick up the pot to feel how heavy it is. If the pot is very light and the soil feels dry to the touch, this is a good sign that your plant needs water.
Use the right soil. Choose a soil mixture formulated especially for African violets. The soil should be loose and light with ample organic matter. Most importantly, use a well-drained soil mix. Heavy soils that hold onto the water will not allow enough air to circulate through to the roots, and your plant will end up sitting in soggy soil.
Use a pot with good drainage. African violets need well-drained soil, but that won’t matter if the pot doesn’t have a drainage hole. You can use a pot made of any material, but it must have decent drainage. This allows any extra water to drain safely from the bottom of the pot.
If your violet has had wet soil and starts showing any sign of wilting leaves, it’s a good idea to check the roots. Gently remove the plant from the pot and examine the roots. Trim off any roots that are brown and mushy, as these have rotted and will not recover.
After trimming rotten parts, repot your plant in fresh soil. Water the soil enough to make it damp, then allow it to dry briefly between waterings.
Petiole rot, or crown rot, is almost always fatal for African violets. Petiole rot is caused by a combination of saturated soil conditions and a fungus that causes the plant to rot.
The roots are affected first, but the rot quickly spreads to other parts of the plant and eventually to the crown. While petiole rot cannot be cured, it can be prevented by proper care and watering techniques.
If your plant experiences crown rot, you will notice a progression of symptoms:
- Wilting leaves.
- Leaves turn dark gray-green in color.
- Slow or stopped plant growth.
- Leaves become mushy and appear to be dying or dead.
- Center of plant (crown) becomes soft, mushy, or floppy.
- The entire plant sags in its pot and looks limp and dead.
First and foremost, do not overwater your African violet. Follow the same guidelines as above under “Root Rot.”
Unfortunately, if the crown of your African violet has rotted, there isn’t any way to save your plant. Once the crown has become soft and jelly-like, the only hope you may have is to try to salvage a healthy leaf. If any leaves still look fresh, firm, and bright green, you can take a leaf cutting, allow it to grow roots, and start a new baby violet.
Botrytis blight, also known as gray mold, is a fungal infection that can affect African violets. This fungus thrives with a combination of high humidity and poor air circulation.
It’s easier to prevent Botrytis blight than cure it, so pay attention to the environmental conditions and any early signs of fungal growth. An untreated case of Botrytis blight will eventually kill your plant.
Plants infected with Botrytis blight will quickly develop a gray fuzzy mold on leaves, stems, and flowers. In addition, you may notice that flowers and leaves wilt, become mushy, or develop brown spots. Leaves will eventually lose their healthy green color and become darker and weak-looking. If allowed to progress, the plant growth will slow, and the plant will eventually turn brown and die.
Some symptoms of root rot and Botrytis blight are similar. Botrytis blight will cause your plant to develop a fuzzy gray moldy-looking growth, whereas root rot causes leaves to turn soft and mushy without visible mold.
The best way to prevent Botrytis blight is to keep your plants in a brightly lit and airy location. Allow plenty of space between plants to increase air circulation. Promptly remove any dead or dying leaves on your plant to keep it in top form and minimize decaying plant matter which can attract fungal growth. Keep your planting tools clean, and always use clean pots when transplanting.
If your plants are suffering from Botrytis blight, isolate any infected plants promptly to help prevent the spread of disease. Remove any dead and dying leaves, stems, and flower stalks. Some fungicides can be beneficial in controlling severe cases. If you opt for chemical treatment, always carefully follow the usage directions on the product label.
Powdery mildew is a fungal infection commonly known to gardeners. Fortunately, it doesn’t typically affect African violets, but it can quickly become a problem if the conditions are right for it. Powdery mildew is most prevalent in humid conditions with poor airflow; once it develops, it can be difficult to remove.
Powdery mildew will cause patches of grayish-white mold on your African violet’s leaves and flowers. A mild case may be hard to recognize, whereas a severe case will be very obvious. Look for a powdery-looking coating on leaves and flowers.
It may appear as small inconspicuous patches or cover the entire leaf surface. It may appear as tiny white speckles on the surface of a leaf, or it may look more like a thicker white mold, depending on how long it has been present.
Mildew will not only be visible on the plant but also affect plant growth. Your African violet may slow down or stop growing altogether. Infected leaves will lose their vigor and turn yellow or slightly brown. Infected flowers may turn brown and die prematurely.
Powdery mildew is caused by a fungus that thrives in warm, humid conditions. Keep your plants in an area that has decent air circulation. You can also improve airflow by allowing some space between each of your plants or providing a gentle fan to help circulate the air.
Crowded plants in a humid environment can be a breeding ground for fungal growth. If you do notice any fungus on a plant, isolate the infected plant immediately to prevent the spread to nearby healthy plants.
Powdery mildew can be treated, but it may take some persistence. First, isolate any infected plants and treat them separately from your healthy plants. Always wash your hands and tools after handling infected plants because powdery mildew can spread easily.
You can create your own anti-fungal solution by mixing 1 tablespoon of baking soda in 1 gallon of warm water. Spray your plants with this solution until the mildew appears to be gone, which may take a few weeks. Remove any badly damaged leaves and focus on helping the healthiest parts of your plant recover.
Water spots on the leaves of your African violet are unsightly, but they are not a sign of a pest or disease. It can, however, be easy to confuse water spots with something more serious.
African violets are very sensitive to cold water, and splashing cold water on the leaves can cause your plant to develop spots or blotches where the tissue turns brown and dies. Once your plant has dead spots, these will not recover, but the good news is that it is very simple to prevent water spots.
Yellow or brown spots, blotches, lines, or streaks appear on the leaves of your African violet. Leaves are otherwise green and healthy, stems and leaves are firm, and the plant continues to flower normally.
You will see water spots on the leaves only if you have watered your plants from the top or accidentally splashed water on the leaves of your plants. If the plant leaves have not been directly exposed to water, they will not develop water spots.
The best way to prevent water spots is to water your plants from below with tepid water and not allow any water to splash onto or sit on the leaves.
- Cold water – African violets are sensitive to cold water, so be especially careful of splashing cold water on the leaves (and don’t water your plants with cold water).
- Chemical exposure – African violets are sensitive to chemicals like chlorine, so allow water to stand for 24 hours before using it to water your plants.
- Wet leaves burn in the sun – Don’t allow wet leaves to be exposed to bright sunlight, as this can cause burn spots.
If you do accidentally splash water on the leaves, don’t worry. Allow your plants to dry thoroughly in a well-ventilated place. Use a tissue or towel to gently blot the water from the leaves. Move a wet plant away from bright sunlight until the leaves have dried completely.
Unfortunately, once a leaf is damaged by cold, chemicals, water, or sun, you can’t fix the damage that has been done. Remove any severely damaged leaves and stems, especially if they become soft or mushy. Take precautions to keep moisture off the leaves to prevent further damage in the future.
Insect pests of African violets vary from nuisance to deadly. Taking precautions to prevent infestations can potentially save you a lot of time, money, and hassle. Follow a few basic rules to prevent (and recover from) insect infestations:
- Isolate new arrivals for several weeks before incorporating them into your plant collection.
- Check your plants frequently for any signs of illness, damage, and disease.
- As soon as you notice insects or insect damage on your plants, isolate any infected plants to prevent further spread.
- Always wash your hands, tools, and pots that have come into contact with infected plants.
Cyclamen mites may be one of the most common insect pests to infect African violets. Unfortunately, these microscopic mites can’t be seen with the naked eye. The first sign of a cyclamen mite infestation is when the plant starts to show visible damage. Keep an eye on your plants so you will recognize early warning signs that something might be wrong.
Since you can’t see cyclamen mites, you will have to diagnose an infestation by looking carefully at your plant’s symptoms. Infected plants may begin to appear dwarfed, deformed, or otherwise misshapen.
The youngest and smallest central leaves turn brown, wither, and die. Sometimes the smallest central leaves die completely while the outer leaves still look relatively healthy and fresh. In severe cases, the entire plant will eventually die.
If you suspect cyclamen mites, isolate infected plants as soon as possible to prevent further spread. Cyclamen mites can be very difficult to control, and badly infested plants should be discarded. If you want to remove the mites, you must purchase an insecticidal soap or miticide spray.
Whichever product you choose, follow the directions carefully and wait until you have eradicated the mites before moving your infected plants near any other houseplants.
Mealybugs are familiar houseplant pests that are fairly easy to identify. Mealybugs pierce the plant’s outer protective layer and suck the juices from within. Infected plants will appear stunted and may grow slowly. Heavy infestations can eventually lead to plant death.
Look for little white fluffy insects clinging to leaves and stems. They may look like little oval balls of cotton. They particularly like to be in corners and bends but can be found on any plant surface. As they feed, they secrete a sticky, wet-looking, sugary substance.
If you see shiny spots on your plant, accompanied by tiny cottony-looking insects, your plant has an infestation of mealybugs.
Isolate any infected plants as soon as you see mealybugs. Insecticidal soaps are relatively safe to use and also effective against mealybugs. Follow the instructions on whichever product you choose. Because you will probably be spraying droplets on your plant, take extra care to keep your plant away from the cold and away from direct sunlight during treatment.
Once you are sure the mealybugs are gone, you can give your plant a gentle shower in warm water to remove any soapy residue and the residue left from the mealybugs themselves.
Scale insects are another all-too-familiar insect pest that commonly attacks houseplants. Although tiny, scales can do considerable damage to your African violet. These pests suck the juices from the plant’s leaves and stem, draining the plant of energy. Affected plants will start to look sickly and can eventually die if the insects are allowed to persist.
Scale insects are very small, about ⅛ inch long, smooth, and flat. They look like little waxy ovals stuck to the leaves and stems of your plant. As they feed, they excrete a sticky substance that appears as shiny wet spots on the leaves.
Look for flat-bodied scales, as well as wet-looking shiny spots. Mealybugs also release secretion as they feed, but the insects look distinctly different, although they are another type of scale.
At the first sign of scales, isolate any infected plants. Scales can be difficult to remove because their flat bodies are well protected by a waxy coating. They can be treated with targeted houseplant insecticides or by dipping a cotton swab in soapy water or rubbing alcohol and removing each scale you see. Repeat this treatment regularly until all scales are gone.
The entire removal process can take several weeks because eggs will continue to hatch. Wipe down the pot and surrounding area with rubbing alcohol to help kill any eggs or wandering insects.
Aphids are a familiar pest to many gardeners. Aphids are remarkably common on outdoor plants and occasionally come indoors to feast on houseplants.
These insects are highly mobile, but they like to gather in large numbers on their favorite plants, making them very easy to see and identify.
Look for individual insects or clusters of aphids gathered on leaves and stems. Aphids are small, about ⅛ inch long, and can be green, pinkish, or brownish colored.
They can be found on all plant surfaces but often congregate on the undersides of leaves and in tight places such as crotches and bends. Aphids will appear as tiny insects sitting on the plant surface, but they are also highly mobile and will move when disturbed.
If you see any aphids on your plants, isolate infected plants immediately to minimize spread. Aphids can be killed with insecticidal soap, but you must be persistent and spray repeatedly for several weeks to kill all life cycle stages.
Wipe down the pot and surrounding area to kill off any wandering insects or egg clusters.
Thrips are as much a nuisance as a cause for concern. Thrips can be incredibly abundant, although almost microscopic in size. These are tiny sucking insects that can cause a great deal of damage if not controlled.
Thrips are not obvious to the naked eye, but they can be seen. These insects are tiny (1/16 inch or smaller) with very narrow bodies. They have wings and can fly, but just as often, they scurry from one location to another. Place a piece of paper under your violet and give it some gentle shakes. Look for thrips falling onto the paper below.
Evidence of thrips will be sightings of tiny insects moving about on the leaf surface, particularly when disturbed. You may also see pollen spilling from flowers onto the leaves as thrips nibble on the pollen sacks. If you notice pollen scattered about on the leaves, leaves with white or brown spots on them, and damaged flowers, you can be reasonably sure you’re dealing with thrips.
Thrips can be very difficult to control. They are extremely numerous, multiply quickly, and are highly mobile. If you have one plant with thrips, all plants in the vicinity are likely infected. Because thrips love African violet flowers, you can start treatment by removing all the flowers.
You will probably need to spray your plants with either neem oil or a standard insecticide that targets thrips. Follow directions carefully and use your chosen product until you are sure that the thrips have been eradicated. Also, disinfect all pots and trays that have come in contact with the infected plants.
Foliar nematodes infect the leaves of African violets. These microscopic worms spread from infected plants and from soil infected with nematodes or their eggs. These tiny worms feed on the plant juices and will cause pale, wilting leaves and slow growth. If left untreated, infected plants will die.
You won’t actually see a nematode, but you will see evidence that they are harming your plant. Damage starts with pale-looking or brownish patches on the leaves that slowly enlarge and spread.
You will first notice these shiny brown spots on the undersides of the leaves, and in particular, along the veins. If allowed to progress, the entire leaf will look damaged, and other leaves will soon become infected.
Nematodes are very difficult to eradicate. Because these pests spend their lives inside the plant, insecticides are ineffective. The best treatment, unfortunately, is to discard infected plants. You can try taking a couple of healthy-looking leaves to start new plants from cuttings.
Use leaves only if they show no signs of nematode damage, and keep the rooting leaves separate from your other plants for several weeks until you can be sure they are not infected. If you see any signs of nematode damage, discard the leaves and the soil.
It may feel overwhelming to know there are so many pests and diseases that may infect your African violets. Prevention is always the best course of action.
Choose healthy plants, isolate new plants before introducing them into your collection, and treat infected plants at the first sign of illness. Once you learn the signs and symptoms to look for, you can act quickly to prevent further spread of pests and diseases. Giving your violets the best care possible will also keep them healthy and vibrant.