Why Are There Brown Spots on African Violet Leaves?

African violets are stunning house plants with lush velvety green foliage, as well as stunning blooms that are a sight to behold.

As beautiful as African violets can be however, they can be prone to a variety of problems that can ruin their beauty by causing brown spots. What can be wrong?

The brown spots that appear On African violets are typically caused by diseases like fungal leaf spot, bacterial blight, ringspot, powdery mildew or the rust. Remove your plant from the area and eliminate the affected leaves prior to beginning treatment. Insects excessive fertilizer and issues with watering can lead to the leaves to scorch and cause low humidity.

[1] African Violet Leaf Scorch

Exposed to excessively hot and bright sunlight is the main reason for scorching in African violet-colored leaves. The most common facilitators or enablers are:

  • Heat drafts
  • Extremely low humidity
  • Fertilizer burn
  • Compaction of soil
  • Bacterial leaf scorch
  • Severe nutrient deficiency
  • Water damage caused by softened or chemical substances
  • Poor potting medium
  • The roots of your plant may be overcrowded, and there’s not enough space to grow roots. It’s also possible for the soil to become dry and cause dry and scorched leaves.

Symptoms

If you notice that your African violet leaves appear dry and hard and have brown spots it could be suffering from leaf scorch. It appears like a plant that is over-exposed to the sun. Additionally, the leaves can change color to yellow.

Although a variety of causes could cause brown spots on leaves, scorch on the leaves is an indication of too much sun exposure.

Additionally, you might observe that the plant’s tips as well as the edges are drying up and have turned a dull brown color. It’s also not uncommon for leaves to become affected by the growth.

Treatment and Prevention of African Violet Leaf Scorch

  • The parts that are scorched of the leaves will never turn green and will never turn back green. If the cause is scorched leaves caused by bacterial organisms I would recommend taking out the leaves that are severely scorched and properly removing them. If it’s expected to be caused by bacterial scorch on the leaf, I suggest covering cuts with the cinnamon and shellac.
  • Move the African violets from an overly sunny spot to an area that has plenty of indirect but bright sunlight.
  • After a few days your plant will begin to recover If you provide it with ample water.
  • Place a layer of mulch on the surface of the medium to help retain the moisture.
  • To prevent scorching of the leaves to prevent scorching, give your African violet with dilute water-soluble fertilizer

african violet near window

[2] Powdery Mildew

It is believed that the Oidium fungus is often responsible for powdery mildew on African violets.

The white powdery patches are usually filled with fungal spores and strands that can show up in the form of brown streaks, or tiny specks.

The spores are usually transported or blown by breeze to other flowers and leaves on the same or a different African violet plants.

Mildew that is powdery is found on African violet thrives in certain conditions, such as:

  • A lot of wetness on the flowers or leaves
  • The humidity levels are high.
  • Low light conditions, paired with cool evenings and warm days
  • Air circulation is poor within the plant or between the leaves.

Symptoms

Powdery mildew may appear as fine gray or white substance on any plant that is above soil level.

In extreme instances in extreme cases, your African violet leaves, stems and flowers could be yellowed or bleached, and the growth of new plants could be reduced.

This is due to mildew’s depletion of nutrients and blocks photosynthesis, which results in the yellowing or browning in leaf tissues.

Flowers, buds, leaves and stems that are affected may become swollen, brown and then die. The fungal infection typically is found in African violets that are submerged in water, malnourished, or over-fertilized.

Treatment and Prevention of Powdery Mildew on African Violets

  • Remove the severely affected areas that contain fungal spores. Clean the plant using soapy water to get rid of the dust.
  • Apply the fungicide according to the instructions of the manufacturer. You can choose an organic alternative like Neem oil, or you can try chemical fungicides. Apply the solution every 7 to 10 days until the mildew that is powdery is gone.
  • Maintain a good hygiene in your garden and dispose of any plant matter that has fallen.
  • Place the plant on a well-lit area far from direct sunlight or humid conditions that make it difficult to achieve the recovery of your plant without hitch.
  • Separate the plant affected from all other plants in the house until the plant is completely recovered

[3] Rusts on African Violet Leaves

A fungus can cause rust on African violet leaves. It is evident by the oval or circular bumps that appear on leaves of the plant.

Fingertips are required to remove the spores of the areas that are stuffed with spores. It is most likely to thrive in humid conditions with low air circulation.

But, a combination of humid conditions and wet leaves when irrigation can promote the growth of the rust.

Symptoms

Infected African violets usually display the spores in masses that vary in hues ranging from purple to red to brown , brownish-yellow to orange.

The leaves with these spots exhibit an appearance of rust. They may appear as tiny dots, raised or tiny specks in your African violet’s leaves or stems.

The condition can get worse and develop into pustule-like bumps when left untreated.

The pustules will open and release the spores of fungus that are transported by wind or water to other leaves , and then become brown.

It’s only an issue of time until they spread to healthy foliage and transform the entire leaf into brown spots.

Rust isn’t the most common cause of death for your African violet However, it could affect its growth and health.

There is a gradual decrease in the development rate and small leaves appearing, and the loss of stems.

Additionally leaves that have been badly damaged can become yellow, dry out and fall off too quickly.

Treatment and Prevention of Rusts on African Violet Leaves

It is best to stay clear of the rust fungus completely by taking these easy steps:

  • The overwatering of your African violet can encourage the development of rust fungus that thrives in humid environments.
  • Make sure that the plants you purchase are healthy and disease-free. Also, choose African violet cultivars that are resistant to diseases like rust and.
  • Avoiding overhead irrigation. To prevent water splashing onto the leaves you can make use of the drip irrigation method or soaker hose.
  • You should water your African violets at the beginning of each day, allowing the leaves to completely dry.
  • The spores of fungus can be found in decaying plant material, take it out and dispose of it.
  • Make sure you’re African violet is able to get ample air circulation within and outside of the foliage. This will help dry the leaves. You can think about spacing your plants, or making use of a fan to increase circulation of air.

If your African has rust Here are some alternatives to treat it:

  • Take away and eliminate the affected plant when you first notice the rusty brown hue. Be sure to clean the cutting tools following each cut by soaking them in bleach.
  • Remove and dispose of any fallen plant material. Don’t put them in compost.
  • Treat your African violets with a plant-friendly fungicide such as sulfur dust, Neem oil ( Amazon link) or a copper/sulfur-based chemical fungicide.

[4] African Violet Bacterial Leaf Blight

The bacteria Erwinia Chrysanthemi causes the blight of the leaf caused by a bacterial infection in African violets. Humans, water or insects such as spider mites are able to transmit the bacteria.

Stomata (leaf pores) permit bacteria to get in, however their preferred way of entering is through cuts on the leaves.

These pathogens flourish in hot and humid environments, particularly in the absence of air circulation.

The excess moisture that accumulates on flowers or buds could aid in the spread of bacterial blight. The disease could kill your African violet if not taken care of promptly.

Symptoms

Water-soaked, soft lesions on the leaves from African violets is the most frequent indication of bacterial blight on the plant.

Based on the amount of decay and ooze present They can range from dark brown to black in color.

Furthermore, they affect the crown stems of the plant and roots, too. There are sticky or greasy threads in the affected foliage when you cut the stem open.

Other signs of bacterial blight are:

  • Plant growth stunted
  • Foliage forms holes in the areas where bacterial blight caused the damage.
  • The leaves may appear pale; some might appear yellowish, grayish, or brown.
  • The leaf develops brown spots, particularly on the undersides.

Treatment and Prevention of Bacterial Blight on African Violets

A blight-like infection that is bacillary in nature is usually permanent and incurable. The best way to prevent it is to prevent problems from the beginning.

  • Make sure to use a sterilized growth medium and a pot that has been disinfected prior to potting or refilling the plants of your African violets.
  • Always clean thoroughly and wash your hands prior to handling any plant.
  • Do not water your plants from above or splashing it on the leaves. I strongly suggest that you make use of a self-watering pot.
  • Do not use too much fertilizer.
  • Beware of abrupt extreme temperature fluctuations and abrupt changes in temperature.

To treat, follow these steps:

  1. First, you must remove the infected violet.
  2. Utilizing a pair of sharp pruning scissors that are sterilized take out all dead and infected leaves.
  3. After every cut, clean the cutting tool with bleach solution that is 9 parts water to 1 part bleach.

[5] African Violet Foliar Nematode

It’s caused by microorganisms that resemble worms which feed on the tissue within the African violet.

Nematodes feed on cells and then lay eggs within the leaves, which result in the leaves turning brown. Since these organisms are so small that they can’t be observed with eyes alone, it’s likely to miss them.

African violet pathogens typically get into the leaves via pores or through wounds caused by cuts, pest damage or any other injury. Foliar nematodes can be deadly to plants when they aren’t treated promptly.

Symptoms

There aren’t any obvious signs of foliar nematode infections in the beginning stages. But you may find that your African violet may already be infected before you even realize it.

The most noticeable sign can be seen in the form of sparkling brown spots that appear on the leaf blades’ undersides. Between the veins of leaves they usually have an orange-reddish circle.

The undersides of the leaves are flecked with tiny, hollow brown dots. As they mature they lose their shine and begin to become dry. African Violet foliar Nematode signs include:

Other symptoms that are common to foliar nematode in African violet include:

  • The stems can become swollen.
  • Wilting leaves have an appearance of translucent brown and are soft to the feel.
  • Leaves can turn dull, pale yellow or grayish.
  • The foliage may show yellow spots.
  • Shiny spots in brown on the leaves
  • Plant growth stunted

Treatment and Prevention of Foliar Nematode

After you’ve discovered that the Foliar Nematode has spread to your plant, it can’t be removed. Therefore, you’ll need be able to do anything to prevent it from happening:

  • Clean the containers and apply an untreated growing medium for you are repotting your plant.
  • Before you handle the African violet, make sure you thoroughly wash your hands.
  • When you water your plant, be careful not to splashing your leaves.
  • Separate sick plants and newly planted ones until you’re sure that they are healthy.

[6] Ring Spot

Ringspot Also known by the name of water spots is the result of an abrupt decrease in the temperature of the leaf.

It drastically reduces the rate of photosynthesis, and can cause irreparable damage to the palisade cells in the leaves. The above-ground irrigation with chilled water can be the main frequent reason.

Similar things can occur when you pour cold water over the leaves.

Ring spots of light brown color can develop if the temperature of the leaf decreases between 95degF (35degC) up to 77degF (25degC) abruptly.

The rings can join to create odd brown spots on the leaves.

There’s no way to reverse permanently ring marks created by temperature variations regardless of the length they’re exposed for.

The rings are more bearable in certain African purple cultivars than in others.

Symptoms

The most noticeable signs are the appearance of brown to white rings, arcs, lines, or streaks in the leaf. Additionally, there is the possibility that they could join into strange-shaped patches.

Treatment and Prevention of Ring Spot

In the case of abrupt temperature fluctuations, African violets are extremely sensitive to sudden temperature changes. Ring spots however are not able to be eliminated.

So, in order to stimulate your plant to grow new leaves that are free of ringspots, you must rectify the issue and apply appropriate cultural controls. To do so here is how:

  • Make sure to use room temperature water for watering your African violet
  • You can water your African violets from below
  • Be careful not to splash cold water over the leaves.
  • Plant cultivars that are less prone to temperature fluctuations

[7] Pest Infestation

The brown spots that appear on African violet leaves may be the result of a pest problem.

They may be caused by tissue damage directly or secondary infections caused by pathogens that are opportunistic.

Mealybugs: African violets are prone to certain species of mealybugs. The citrus mealybug as well as the Comstock mealybug are two of them.

They have a spongy body , and measure about one quarter inch in length. They look like cottony due to a waxy white coating.

Symptoms

Be on the lookout for a sticky substance that resembles cotton in the crevices as well as on the leaves and stems on the plants.

Excessive sugary excrement produced by bees draws ants and triggers the growth of black sooty mold. They then alter, stunt and turn the leaves yellow when they consume the leaves.

Prevention and Control of Mealybugs

  • Check new plants for signs of pests. Be sure to check for eggs of mealybugs at the bottom of the pot.
  • Infestations that are light can be eliminated by rubbing alcohol-soaked cotton swabs. Repeat the process until the mealybugs have gone.
  • You can consider using non-toxic insecticides like pyrethrins, insecticidal soap or Neem oil to treat moderate to mild infestations.
  • The oil of Neem and the insecticidal soaps are sufficient for serious infestations of mealybugs.
  • To control mealybug eggs and larvae, apply imidacloprid-containing insecticide granules to the soil (check the latest Amazon price here).

Cyclamen Mites

They aren’t actually insects , but are rather spider-related. They are, however, the most prevalent and significant pests that plague African violets.

They’re tiny enough that you’ll be unable to observe them through your eyes.

The low light and extremely humid conditions (humidity levels between 80 and 90 percent), and temperatures that are cool, around 60 °F (15degC) are perfect for mites.

Symptoms

Cyclamen mites like to feast on the new growth that is growing in the crown’s middle.

Gray-colored hairy leaves and swollen central leaves can be among the more frequent signs.

The ravages of flower and leaf bugs often cause deaths of the bugs. Sometimes, flower buds don’t open.

Prevention and Control of Cyclamen Mites

  • Plants should be spaced out to stop spreading Cyclamen mites
  • Infested with a lot of African violets must be eradicated.
  • If you want to save plants that are saved, apply an insecticide spray that is labeled to African violets.
  • You may want to consider using a mite spray (Check the most current cost at Amazon Here).

[8] Fertilizer Overdose

The excess fertilizer salts in the soil could be the cause If your African violet is brown with edges and tips.

A high concentration of salt in the medium can damage the roots, and may result in leaves to “burn,” which appears as brown spots on the leaves.

When the rim of the container meets the leaves, brown spots can appear. Similar to stems, which may have brown streaks when they rest upon the vessel.

Prevention and Control of Fertilizer Overdose

  • Get rid of any crusty scabs or fertilizer salts that have accumulated on the medium’s surface.
  • Intensely water your plant to eliminate the fertilizer salts that are accumulating. Let the water percolate throughout the soil for approximately 15 minutes. Repeat the process until all salts have been eliminated.
  • Pot your African violet with a new pot of potting mix that is well-drained and that is specifically labeled for the plant.

African violet leaves may be affected by brown spots as a result of natural aging and conditions like low humidity.

This article will teach you how to tackle particular issues and put solutions into practice.

Stephanie

Stephanie

Went from a bad gardener to a half-decent one over 10+ years. Super happy to share my tips and tricks with you :)