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Treating Powdery Mildew on a Kalanchoe (White Powder or White Spots)

Treating Powdery Mildew on a Kalanchoe (White Powder or White Spots)

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Kalanchoe is a popular houseplant, especially for new plant moms. This low-maintenance plant is easy to grow because it thrives in dry environments.

Given with proper care, it blesses you with beautiful flowers in variants of yellow, pink, red, orange, or white.

But what happens when you start seeing white powder or white spots on your kalanchoe’s leaves?

Don’t think of yourself as a neglectful plant mom immediately! Powdery mildew isn’t incurable, and we’re here to help you out.

What Is Powdery Mildew?

Powdery mildew is one of the most common problems of Kalanchoe plants. It’s a fungal disease that affects many different plants.

It starts as white powdery spots on the leaves of plants. Sometimes, it can also be under the leaves, on stems, or on flowers of your Kalanchoe.

This can also spread to other parts of the plant if not treated immediately.

If new foliages are growing in your kalanchoe with untreated powdery mildew, your prompt intervention is crucial. If they’re not taken care of, they can dry out and turn yellow.

Aside from seeing white spots as if the leaves are sprinkled with flour, infected stems can show obvious signs of spoilage.

How Do I Treat Powdery Mildew?

Powdery Mildew Close Up

Mild powdery mildew infections can sometimes go away on their own. Unfortunately, this still shouldn’t be overlooked.

Any kind of intervention to prevent the fungi from attacking again is necessary. A little extra TLC for your Kalanchoe is also always welcome.

So, how do you treat powdery mildew?

Method 1: Cultural Control

Cultural control is basically reassessing the conditions that your plant actually needs.

This could be in terms of water, soil, sunlight, and temperature. The healthy mix of these guarantees your kalanchoe to be blooming, glowing, and flourishing.

Watering Needs

Since Kalanchoes are succulents, they don’t need as much water as other plants. In fact, overwatering your kalanchoes will make them rot faster.

A nice trick to knowing whether your kalanchoe needs water is by sticking your finger into the topsoil, about 1-2 inches deep. If your fingers come out completely dry, that means your plant is thirsty.

Typically, you’ll only need to water them every 2-3 weeks, but it’s recommended to still check every few days.

Another trick to prevent overwatering is bottom watering. By letting them absorb the water from below, your plants have more control over how much water they get.

Type of Soil

Kalanchoe plants outdoors do great in sandy and well-drained soils.

If yours are indoors, it’s still best to pot them with a soil blend that doesn’t retain moisture.

For kalanchoe, this means one part of potting soil to one part of cactus mix. Another recommended blend is 60% peat moss mixed with 40% perlite.

Exposure to Sunlight

Kalanchoe In Bright Light

Although kalanchoes love light, they don’t thrive under direct sunlight. Instead of blooming, their leaves tend to burn.

Make sure to place your indoor kalanchoes in an area with bright but indirect sunlight.

From the seasons of fall to early spring, kalanchoes can be exposed to direct sunlight. This is because the sunlight won’t be as harsh and damaging to their leaves.

Temperature of Environment

Since kalanchoe is a low-maintenance plant, it’s not as picky when it comes to its surroundings. Temperature from 55°F to 80°F is a great range for them.

The only thing to remember is to make sure they’re protected from frost. Frost leads to instant death for your kalanchoe.

Method 2: Chemical Control

If you want faster results to control powdery mildews, chemicals are your friends.

By chemicals, we don’t mean bad chemicals. These chemical products actually range from household staples to store-bought chemicals.

Milk Spray

Studies have shown that milk had the same effect as chemical fungicides in controlling powdery mildew.

To concoct a milk spray, mix ten parts of water for every part of milk. For more severe cases of powdery mildew, half and half portions of water and milk is recommended.

Spray this milk mixture to infected parts of your kalanchoe twice a week until desired results are achieved. Whether you use liquid milk or powdered milk, it shouldn’t make a difference.

Baking Soda Solution

Baking Soda For Garden Treatment

Experienced gardeners have used baking soda solution for years to treat powdery mildew.

In a container, mix one tablespoon of baking soda with half a teaspoon of liquid detergent for every gallon of water.

Using this solution, spray affected areas, including the undersides of leaves.

Ideally, this solution has better effects as a preventative measure. So, at the first sight of powdery mildew, you can use this solution to avoid spreading of the fungi.

Neem Oil

Neem oil has been used to control powdery mildew and other plant diseases.

To use this, combine two and a half tablespoons of neem oil in a gallon of water. This should be sprayed on the infected parts for 1-2 weeks to see results.

Neem oil can also be added to your milk spray or baking soda solution for that extra boost of care.

Sulfur Fungicide

When natural methods fail to work, it’s time to bring out the fungicides.

Sulfur fungicide is proven to be the cheapest and most effective method for controlling powdery mildew. Even before symptoms begin, you should already be spraying this onto your plants.

It’s recommended to spray this every week. For outdoor kalanchoes, they should also be sprayed after every rain.

Since sulfur is known to be an irritant, remember to take caution when handling this chemical.

How Do I Prevent Powdery Mildew?

Prevention is always better than cure. Before anticipating any powdery mildew, it’s important to have a healthy environment for it to thrive.

Crowd Control

Kalanchoe Close Together

Plants that are too close to each other are more vulnerable to developing powdery mildew. Because of the limited space, there tends to be poor air circulation.

For kalanchoes, it’s important to keep enough space between each bush if they’re outside. For indoor kalanchoes, make sure to only keep one bush in every pot.


Aside from the proper amount of water and sunlight, pruning also helps in preventing powdery mildew.

You should always trim away leaves, foliages, or stems that are at the end of their lives. By doing so, you can keep other pests and diseases at bay.

Regular Treatment

Despite kalanchoes being low-maintenance, regular treatment is still necessary. This could be through natural or chemical sprays.

Regular treatment ensures that your kalanchoes get the right kind of care to help them bloom.

Final Thoughts

Powdery mildew isn’t a fatal plant disease. There’s always a way to treat your kalanchoe if it contracts powdery mildew.

So, anytime that a white spot or white powder starts appearing on their leaves again, remember the wide range of options available to treat powdery mildew.

With great care, your kalanchoe will surely thank you.

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