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Common Causes for White Spots on Indoor Plants (Plus the Solution)

Common Causes for White Spots on Indoor Plants (Plus the Solution)

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Indoor plants require a considerable amount of maintenance and care if you want them to grow healthily inside your house.

Many indoor plants have different kinds of requirements, so it’s important for you to make sure that you provide them with adequate amounts of sunlight and care for them as much as possible.

However, from time to time, you might notice problems with your plants that require urgent care. Failure to treat these problems could ultimately cause your plants to die as well.

One of the things that you might notice with your plants is the development of small, white spots that appear on the leaves. There can be several reasons for this occurrence, and it’s important for you to make sure that you take action right away.

Powdery Mildew

SS - Powdery Mildew

It looks like talcum powder, but it’s actually not. What you are looking at is powdery mildew. It is a type of fungal disease that can affect a large number of different plants. These diseases are generally caused by a wide array of different kinds of fungi.

It is one of the easiest diseases that you can identify quickly, as the symptoms are so easy to distinguish and appear right away. You will notice white spots appearing on the stems and the leaves of the plants as soon as it’s affected.

You will notice that the lower leaves are more affected by the powdery mildew, though it won’t take long before the symptoms take over the entire plant. Any part of the plant that is above the ground will be covered in that white powdery substance.

Initially, you might notice that fluffy white fungus on certain areas of the plant. Over the passage of time, this is going to take over the entire plant and it won’t be long before the plant begins to die.

However, you should know that the fungus can also affect the plants indoors. The mycelium that forms on the fungal spores is what causes the fluffy white substance on the plants. These spores tend to spread out in the air, especially when water splashes on the plants.

How to Fix the Problem

You need to understand that powdery mildew is usually caused due to the conditions surrounding the plant.

If you can eliminate those conditions and make the place favorable, you won’t have to worry about using any chemicals. The first step that you need to take is to improve the air circulation in your house.

This is essential as it breaks up the life cycle of the powdery mildew. Most people place their indoor plants in corners of the room.

Fiddle Leaf Fig in Corner of Room

Unfortunately, air tends to stagnate in these areas, and this provides the perfect conditions for white spots to appear. More importantly, if you have kept several potted plants with each other, you need to space them out.

Make sure that the foliage of one plant does not touch others. This can prevent the spread of the powdery mildew as well.

The top half inch of the soil of most of your indoor plants must be allowed to dry properly before you water them again. If you notice the soil is still damp, it’s best if you avoid watering right away.

Remember, the saucers you keep under the plants are only useful for catching dripping water. You should never use them as a pail for catching all of excess water.

More importantly, you must never leave them full at all. Remember to drain your saucers and clean them once you are done.

There are different kinds of horticultural oils that you can find in the market, like Bonide’s All Seasons Horticultural Oil. Even neem oil is a great choice, especially when you consider the many benefits that it offers. They are incredibly effective in getting rid of the stubborn mildew that develops on the plants.

However, before you start spraying the plants with these horticultural oils, you should always move it away from the window.


SS - Mealybugs

Another issue that may result in white powdery substances developing on your indoor plants is the presence of mealybugs.

Mealybugs can leave a thick, cotton type wax on your plants. This wax will usually accumulate on the foliage of the plant, and you might even notice it on the crotch of the branch.

These insects are usually pink or gray in color, and they leave behind a velvety appearance in areas where they feed. You might notice the leaves turning yellow if the infestation of mealybugs only grows, and the plant may begin to die as well due to the infestation.

The problem is that these bugs tend to produce honeydew, which tend to attract ants and can also lead to the creation of mold colonies throughout the branches and the stems of the plant. To identify these plants, you need to look for small patches of cottony wax on the plants.

If the white powdery substance is all over the plant, it might be powdery mildew. However, if it starts by appearing in thick patches on different areas of the plant, you are probably looking at a mealybug infestation. They usually lay their eggs in these white areas.

You might even notice their cluster on the underside of the leaves, as well as where the leaves connect with the stems.

Keep in mind that a few mealybugs won’t cause any damage to your plants, but once they begin to grow and start feeding in earnest, your plants are going to die very soon.

How to Fix the Problem

Thankfully, taking care of mealybugs is as simple as you might think. A light infestation can be removed by just picking them off the plants.

You can use rubbing alcohol to kill them first. If the infestation has grown, you might need to spray a mixture of insecticidal soap or even horticultural oil.

In some plants, you can also apply imidacloprid. This spreads throughout the plant, killing the pests that feed on it. These are just a few tips to get rid of the white spots on your plants!

Before you go: Now is the perfect time to start tracking your gardening progress, and I created a garden journal to do exactly that. Click the image below to see it in action and to get your own copy.

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