Why Are My Pepper Leaves Turning White – Causes & Remedies

Whenever one of our plants turns a color other than the beautiful green we hope for, it can cause concern. Yellowing leaves are usually a sign of overfertilization or underwatering. Browning leaves are also a sign of underwatering and too much sun or heat, but what does it mean when your pepper plants turn a less common color? Why are my pepper plants turning white?

Your pepper leaves are turning white because they are covered in powdery mildew. Powdery mildew is a fungal disease that spreads through plants and is often found on plant leaves. You can identify powdery mildew by its characteristic layers of white that sit on leaves and stems. It can easily spread in peppers if not treated.

So what causes powdery mildew, and what can you do about it? Read on to learn more about powdery mildew and how to protect your pepper plants from this rapidly spreading fungal disease.

What Causes Powdery Mildew?

White powdery mildew looks as if the plants have been dusted with flour. It will start as small white dots on the leaf before spreading throughout the whole leaf, top and bottom, and into the plant stem. 

The weather is the main concern for white mildew. It seems to spread quickly when the weather is warm and humid. The moisture in the air will help feed the mildew so it can grow and spread quickly. 

The main cause of spread other than the natural course is wind. The breeze will blow the fungal spores from plant to plant. This is primarily a concern if you have many pepper plants growing to hear one another. 

Blocking the wind is not a good strategy for preventing white powdery mildew. Your pepper plants thrive with open-air circulation. Also, the wind helps pollinate the pepper plant’s flowers. Pollination is needed for the flower to grow into a pepper once the bloom fades. 

While bees and other pollinators are commonly thought of as the only way that pollination can happen, wind helps spread pollen amongst the flowers and sometimes results in pollination. Gently shaking flowers can also help create pollination. 

How It Spreads

White powdery mildew also spreads through water splashes. During heavy rain or hose watering from above, the water can splash from the middle-infested leaf and settle on other leaves. When mildew spores are transmitted through water, they already have the moisture to help them grow and thrive. 

Pests like aphids, thrips, and whiteflies can also spread white powdery mildew as they travel from plant to plant. While this transfer is the least common, it can also lead to bigger problems.

Aphids can eat through and destroy crops at rapid rates. Treating your plants for these pests multiple times during the season is best to prevent damage or loss.

Sadly, humans can also help powdery mildew spread. It is important to always clear your sheers with rubbing alcohol after every snip when trimming plants. The alcohol kills any bacteria or fungus that may have been on one section of the plant and prevents these diseases from transferring to other parts of the same plant or an entirely different plant. 

Simply cleaning your sheers between cuts can help protect your entire garden. Pests, diseases, molds, and mildews can easily overtake and destroy crops within days. Often, infested plants need to be removed from the garden space to help prevent the spread of disease to other healthy plants. 

Other Causes For White Leave On Peppers

In addition to powdery mildew, there are a handful of environmental factors contribute to pepper plant leaves turning white. The color change often tells you something is wrong with the plant, and the issue needs to be resolved as soon as possible. 

Disease

Disease is one of the more common reasons why pepper plants are turning white. A few diseases will cause leaves to turn white on plants. Powdery mildew is the most common one, followed by mosaic virus and blight. 

Mosaic Virus– Mosaic virus is an intense virus that can affect almost anything in your garden. If it isn’t controlled, it will greatly affect your yield. Mosaic virus is spread through contact with bugs. Mosaic virus looks like white, yellow, and brown spots on the leaves that grow bigger as the disease gets worse. 

Blight– Blight is a fungal disease. It starts as small brown-looking spots on the stems of pepper plants that eventually start like a white puss substance. As the blight spreads, the plant’s leaves will start wilting and yellowing, eventually turning brown. 

Overwatering

Pepper plants can survive happily with about one inch of water a week. They like having a constant flow of oxygen through their roots and can get easily drowned out if they get too much water. Overwatering would cause the leaves to wilt, turn pale and turn white because the airflow isn’t getting to the leaves, also leaving nutrients behind. 

Lack of Nutrients

Like all plants, peppers need nitrogen in order to grow and remain healthy. Nitrogen is what helps plants not only grow in height but also helps them stay a vibrant, healthy green color. Without a proper amount of nitrogen, the leaves of pepper plants may start to lose their green color and start looking white. 

Sunscald 

Sunscald happens when the plants have too much direct sunlight in hot temperatures. Pepper plants do like full sun; however, they thrive best in temperatures of 70-80 degrees.

When it is above 80, and the sun is blasting the leaves of the pepper plants, the sun will burn the leaves of the plant. Sunscald also affects the plant’s fruit; however, it will cause the leaves to appear burned on the tips and start turning white. 

What Can I Do About Powdery Mildew?

Like with most plant diseases and funguses, prevention is the key. Once a plant becomes visibly infected or infested, it is often too late to rehab it back to its former glory. 

If you are able to catch the powdery mildew early, saturating the entire area frequently with fungicide may kill the powdery mildew, but it will require a lot of work and is usually only successful if you catch the fungus before it begins to spread. 

To help create conditions that are not conducive to the spread of disease, be sure to avoid overcrowding plants. When plants are grown too close together, they do not get enough air circulation between the leaves. They may also create too much shade for the leaves to dry out properly after rain, watering, or morning dew. 

You also want to prevent any situation that would result in the leaves of the plants overlapping. 

Planting Tips To Prevent Powdery Mildew

When planting your pepper plants, plant them in places of full sun. Not only do these plants need full sun to produce peppers, but the sun will also warm and dry leaves, helping to control the chance of fungal infections. 

Another tip for avoiding fungal infections is to water your pepper plants from the bottom. Instead of using a sprinkler or an overhead watering hose, place the hose nozzle at the base of the pepper plants. This will help prevent any moisture from getting onto the leaves. 

Check your leaves thoroughly, top and bottom, for any signs of white powdery mildew. Take action immediately if you notice any white spots or places that may be the start of the fungal infection. 

Choose a fungicide that is meant to be used on powdery mildew. You can find these sprays at your local garden centers. 

If you do not want to use chemical fungicides, there are plenty of organic or homemade options that you can use to treat white powdery mildew. 

Adding 1 part milk to 9 parts water is said to be as effective as a chemical fungicide at treating white powdery mildew. 

Making a garlic spray is another organic way to treat fungal diseases. Blend two garlic bulbs with a small dish soap and strain through a cheesecloth.

Store the mixture in the fridge until you are ready to make the spray in a spray bottle mix 1 part garlic mixture and ten parts water. Spray liberally on all infected and nearby leaves and let dry.

How To Cure Pepper Plants White Leaves

The leaves that are affected and look damaged can be removed. However, this doesn’t remove the underlying issue. You will have to fix the source of the white leaves, or else the rest of the plant will suffer. Here is how you can stop the spread or fix the issue of whatever is making your pepper plant leaves white. 

Disease

Diseases can be a real problem in gardens; not all of them can be cured. 

Powdery Mildew- Since powdery mildew is a fungus, it needs dry conditions in order to go away. The first step to taking care of powdery mildew is to be extra cautious when watering. Never get the leaves wet; only water the roots, and try to only water in the mornings.

You can spray the plants affected with baking soda, liquid dish soap, and water. You can also spray the plants with water to wash the mildew. Only do these sprays on warm, dry days, in the mornings, so the plants have time to dry off. 

Mosaic Virus- An example of a disease that has no cure. Removing the affected plants immediately is the only real way to curb the spread of this disease. Do NOT compost them; this will only spread the disease further. You must burn the diseased plants or throw them away. 

Blight- Blight can also not be cured. The affected plants must be removed in the same way you would with the mosaic virus. Blight will also live in the soil for years afterward, so you will need to sun-treat your soil.

Once the plants are removed, water the soil with a hydrogen peroxide mix and let the sun soak into the soil. Wait a season before planting anything in the same soil again, and always rotate your crops. 

Watering

Make sure to have your watering schedule very specific. It helps if you plant your plants in a well-draining loamy soil. Pepper plants are on the lower end for water needs, with only 1 inch per week. So, deep water your pepper plants once or twice a week to achieve that goal. If it’s very hot and dry outside, you may have to water every other day. 

Nutrients 

The start to making sure your plants have enough nutrients starts in the very beginning. Before you even plant your plants, mix your soil with a well-balanced, organic fertilizer with an NPK of 10-10-10 to start. Once your plants are planted, you can feed them a liquid nutrient feed twice a month. 

As your plants are growing, they like a diet with more nitrogen. Having an NPK of 10-5-6 is a great example of something to feed your plants in a vegetative state. When your plants begin to form fruit, cut back on the nitrogen and boost the potassium levels. 

Sunscald

It can be hard to battle sunscald, as it’s impossible to control the weather. Before your plant your pepper plants, make sure they are in a well-lit area, maybe with a small amount of shade in the late afternoon (if you live in an area that gets extremely hot).

If you cannot plant them anywhere but the direct sun, you may want to consider putting shade cloth up over your plants if the weather is going to get above 80 degrees. 

Can You Eat Peppers That Had White Leaves?

Unless your plants suffer a greater problem such as blight or mosaic virus, pepper plants that suffered from overwatering or sunscald will be perfectly fine to eat. Peppers that lacked nutrients are still edible, though they may not taste as good since they lacked the nutrients they needed to grow. 

If your peppers have white spots, they are also usually fine to eat. All you have to do is cut around the white spots and continue as normal. Keep your eye out for any signs of mold or rot, as you don’t want to consume that. 

Final Thoughts

White leaves on pepper plants are not a good sign. It is most like white powdery mildew. This fungal infection gets its name from the flourlike texture and appearance of the mold spores. 

Sadly, this infection is tough to treat unless caught in the early phase. Checking your leaves regularly for signs of infection is a good way to prevent an outbreak.

Other ways to prevent outbreaks include cleaning and disinfecting your garden sheers between cuts and avoiding overcrowded plants.

Be sure that plants have enough space for air to circulate through. You also want to ensure that pepper plants are in full sun. This will help prevent moisture from sitting on the leaves. 

Watering plants from the bottom instead of from sprinklers or overhead watering hoses will ensure that water does not pool on the leaves, creating the ideal environment for mold to grow.

Treating white powdery mildew with chemical fungicides is the best way to prevent the spread at the first sign of infection. You can also use organic or homemade sprays if you are hoping to avoid using chemical sprays in your garden space.