The African violet is one of the most popular houseplants in the world, thanks to its beautiful, bright flowers.
It is native to Tanzania and Kenya, but has grown in popularity and is often grown as an indoor plant in the United States.
If your African violet’s leaves are turning white, this means that there has been a change in its environment or its living conditions that is causing the plant stress, triggering the discoloration.
The most common reasons an African violet’s leaves turn white are too much sunlight, water on the leaves, powdery mildew, variegation, temperature and light changes, mites and nematodes.
In this article, we will discuss each of these causes and how you can remedy them. So, if you are having this problem with your African violet and you wish to learn more about it, just keep reading.
Why are my African violet’s leaves turning white?
Too much sunlight
The part of Africa to which this plant is native generally has a warm climate, so people sometimes believe that African violets love lots of bright, direct sunlight.
This is a misconception, of course. African violets actually prefer indirect light to survive and to thrive.
If the plant is getting too much direct sunlight every day, it can cause its leaves to turn white.
The discoloration is due to the chlorophyll in the plant’s leaves being destroyed by the sun’s UV rays. This is called leaf bleaching. It can also lead to stunted growth, because chlorophyll is essential to plant growth.
The plant’s ability to flower will also be reduced in this situation.
If you suspect that your African violet’s leaves are turning white because of too much direct sunlight, move the plant to a shadier location immediately.
If the plant is kept outdoors, move it to a spot under a large tree where it will only get dappled sunlight throughout the day, or to a porch or a patio.
If the plant is kept indoors, move it away from any window that lets in harsh light, and rather place it near a north- or east-facing window.
If you are living in an apartment where the only available windows let in harsh light, you can hang a sheer curtain over the window to diffuse the light.
Rotate the plant every week so that all sides get their time in the light and so that the plant does not become leggy.
If you live in a home that does not get much natural light, you can always use a grow light. Natural light is always best, but a grow light is a fine alternative.
Water on the leaves
Another reason your African violet’s leaves are turning white may be due to water on the plant’s leaves. This is a common mistake among novice African violet owners who do not know how to water their plants correctly.
The water droplets that remain on the leaves will leave white spots or patches because the plant’s leaves are sensitive and do not take well to getting wet when watered.
If you think that the white spots could be because of water on the leaves, change the way you water your plant.
Water the soil directly and do not water the plant from above. You can do this by using a watering can with a long, thin spout. Move the bottom leaves aside and place the tip of the watering can directly on the soil.
If the white spots are bothering you visually, you can simply remove those leaves. If not, just leave them and wait for them to naturally fall off over time.
Another common cause of white leaves on African violets is powdery mildew.
This is a fungal disease that affects many types of plants and presents as powdery, white spots on their stems and leaves.
Unfortunately, it can be quite difficult to prevent your plant from acquiring this disease, especially if it is grown outdoors, because the disease spreads via insects that crawl or fly from one plant to another.
A humid environment is also most conducive for the growth of this mildew.
If you suspect the white leaves on your plant to be due to powdery mildew, try to nip the infection in the bud by removing the leaves that have turned white.
Move the plant to a different location where there is better air circulation and lower humidity.
You can also use a fungicidal spray to kill the mildew. If you do not like using chemicals on your plant or around your house, you can make a neem oil solution by mixing two tablespoons of neem oil into a spray bottle full of water.
Treat the plant once a week until the white spots are gone. You can continue spraying the plant once a week as a preventative measure so that the infection does not recur.
Make sure the plant is quarantined in a different room so that your other healthy plants do not get infected.
Sometimes the white parts on your plant are completely normal and nothing to worry about, such as when your plant’s leaves are naturally variegated and therefore not completely green in color.
Variegation on plant leaves is due to spontaneous genetic mutations and is an often highly-coveted characteristic of plants.
These plants usually start out all green, but because of the mutation, some sections of the leaves turn white. The white leaves are this way due to a lack of chlorophyll, which is the pigment produced by plants that gives them their distinctive green color.
Because the variegated leaves lack chlorophyll, expect them to grow more slowly than those that are completely green. The variegated leaves will also need to have much brighter light because of their lack of chlorophyll. If the plant feels that it is not getting enough light, it will instinctively grow predominantly green leaves with more chlorophyll in order to gather more energy.
The presence of variegated leaves does not harm your plant in any way, so you can leave them on the plant, but if you do not like the way they look, you can remove them if you want to.
To encourage the growth of green leaves, just move the plant away from its light source and it should be motivated to produce more green leaves.
Changes in temperature and even light can also trigger a color change in your African violet’s leaves. These color changes are not that noticeable at first. They may appear quite subtle and will not immediately be an opaque white color. The flowers may also turn white, along with the leaves.
Like the spontaneous genetic mutation mentioned above, this change in leaf color is not harmful to the plant.
Íf you do not want this to happen because you do not like the white leaves, just make sure that the plant only gets indirect light. Keep it in a room with a stable temperature and light source so that its propensity to mutate is not triggered.
A common pest on the African violet is the cyclamen mite. These bugs are so small that they cannot be seen by the human eye.
They are drawn towards plants that are kept in warm, humid places, so if you keep your plant in a greenhouse, this is a pest that you should always be looking out for.
The cyclamen mite uses its mouth to pierce the plant’s leaves and feed on the contents of the cells in the leaf tissue. This feeding behavior inflicts considerable damage to your African violet, despite the diminutive size of the mite.
It is almost impossible to catch the infestation in its early stages because of the mites’ tiny size. The only time one really suspects their presence is when the plant’s leaves start curling inwards, becoming distorted and discolored. The leaves will also become blotchy and streaked with white patches because of the large mite populations feeding on them.
If you suspect a mite infestation, take the plant away from your other plants to stop the pests from spreading.
If the infestation is too serious and the plant is not doing well, it might be better to throw the entire plant away rather than risk a widespread infestation in your other plants.
If you think the plant is still salvageable, you can try and save it by submerging it in 110-degree Fahrenheit water and keeping it submerged for at least 30 minutes.
This method will kill the mites but it may not be able to kill all of them.
You can also use an insecticide on your plant; just make sure you keep it quarantined while you are treating it. Prune off the infected areas using a sterile knife or pair of scissors, and repeat the process every week until you are sure that all of the mites have been eradicated.
A nematode can also cause the leaves on your African violet to turn white.
The presence of the root-knot nematode will cause nutrient stress in your plant, which can also cause stunted growth and yellowing and wilting of the leaves.
Signs of a nematode attack on your African violet include blisters on the roots, which are tricky to spot. Furthermore, the nematodes are quite small and live in the soil, which one rarely, if ever, inspects.
The effects on the plant above soil will take a bit of time and will only appear when the damage to the roots has become quite substantial.
If you happen to catch a nematode infection, separate the plant from your other plants immediately. You will need to dispose of the infected plant properly and as soon as possible, because there is no cure for this infestation.
The African violet is a beautiful houseplant notable for its bright flowers that can bring life and color to any household.
A common complaint among African violet owners is the whitening of their plants’ leaves.
The most common causes of white leaves on these plants are too much sunlight, water on the leaves, powdery mildew, variegation, temperature and light changes, mites and nematodes.
Image: istockphoto.com / Tatiana Kutina