Pepper Leaves Turning White (Causes and Treatment)

Taking good care of your pepper plants and considering their microclimate is the cornerstone of their well-being. I’ve noticed that pepper plants can be extremely sensitive, where even the smallest deviation from their ideal growing conditions can put them under the weather.

If you’ve started to see your peppers looking a bit off, with leaves turning white after transplanting them, this could likely be a stress response to their new environment.

But let’s not forget, pepper plants are incredibly resilient and can bounce back from simple stressors, like moving to a new garden bed.

You can anticipate their color returning within a few days after settling into their new home.

However, I should point out that there are other reasons why pepper leaves may turn white, which could spell disaster for your plants if you don’t determine the cause and act promptly.

Causes of White Leaves on Pepper Plants

The most common cause for plant leaves turning white includes improper care, a deficiency in certain nutrients, sunburn, and sometimes, a lack of hydration.

No matter the case, I’ve observed that a color change in the leaves often accompanies the following symptoms:

• Deformed leaves and fruits
• Falling leaves and flowers
• Underdeveloped fruits

It’s crucial to remember that with improper care, the whole plant suffers, not just the leaves. The root system, stems, flowers, and fruits take a hit in this scenario.

There can also be other causes, such as diseases resulting in white spots on your pepper plant leaves. It’s crucial to diagnose these diseases correctly.

If a fungal or bacterial disease infects your plant, and you’re merely trying to improve the plant’s microclimate or care system, your efforts won’t yield any positive results.

Ultimately, your plant will suffer, and recovery from the damage may be delayed.

Often, I reflect on the errors or missteps I’ve made that resulted in my plants suffering. One common error is in the planting and pre-planting preparation.

That’s why I share the common mistakes I’ve made or seen other gardeners make.

Let’s delve into the most common horticultural blunders gardeners commit and discuss the conditions necessary for normal growth and development of peppers.

We’ll also examine diseases typical of this plant that exhibit similar symptoms.

White Leaves on Pepper Plants: A Problem with Farming Methods

Peppers appreciate warmth and light. They cannot withstand abrupt temperature changes, significant cooling, direct sunlight, or drought.

The pepper plant has taught me the required routine, so I’ve committed to maintaining its ideal conditions.

All I have to do now is ensure I meet all the requirements for my pepper plant to thrive.

Ideal conditions for peppers:

• Daytime temperatures within 73-82°F and no lower than 54°F at night.
• 10-12 hours of daylight.
• Soil that’s light, loose, nutritious, and not acidic.
• Water with warm water in the morning or evening hours.
• Timely fertilization and protection from pests.

Neglecting these conditions could lead to the leaves of your peppers whitening or even falling off entirely. Additionally, several other reasons could provoke such behavior in this culture.

Hardening

If you have planted peppers in a bed without a two-week preliminary hardening period, their leaves will most likely turn white.

It’s not so much about the plant getting used to the outdoor or greenhouse conditions after being indoors but about the leaves’ adaptation to direct sunlight.

An unhardened plant can get sunburned when exposed to the open sun.

Watering

Watering during hot, sunny weather with droplets landing on the leaves can also lead to sunburns, which appear as white spots.

That’s why it’s recommended to water peppers in the evening or early in the morning.

Cold water acts like shock therapy on the roots, which can change leaf color. Drying out can cause pepper leaves to lighten, just like excess water.

By overwatering the plant, you risk inviting fungal diseases: black leg, and various rots, from which it is not always possible to recover. You should water the peppers when the ground has noticeably dried out.

Soil

Acidic, heavy soil doesn’t bode well for peppers. In such conditions, it’s no surprise if the pepper leaves change color to white.

In this case, I try to neutralize the soil with ash. Incorporate fertilizers such as well-rotted manure and compost into it. Sawdust and sand can help lighten and loosen the soil.

Fertilizer Application

Pepper leaves might turn white due to the following:

• Magnesium deficiency;
• Iron deficiency;
• Overwatering of roots (lack of proper drainage);
• High soil acidity;
• Nitrogen deficiency.

Each plant requires fertilizer every 1-2 weeks once the plant is established. Water the plant before fertilizing. Apply the fertilizer in the morning or evening or on a cloudy day.

You can fertilize the plant at the root by spraying the leaves. Remember that peppers require different amounts of minerals at different growth stages.

For example, when the plant grows stems and leaves heavily, you must supply fertilizer with more nitrogen. 

It’s best to fertilize according to the following method:

• Before flowering, provide more nitrogen fertilizers.
• During flowering, emphasize boron.
• At the fruit set stage, apply calcium to the root.
• In the fruiting phase, the pepper needs more potassium.

Here’s what fertilizers peppers need:

Nitrogen fertilizers:

• Urea – approximately 0.7 to 1 ounce (20-30g) per bucket
• Chicken manure – Dilute with water at 1 part manure to 20 parts water. You can also use store-bought manure, which includes mineral additives.
• Cow dung or green manure – Dilute with water at 1 part dung to 10 parts water.
• Saltpeter – approximately 1 ounce (30g) per bucket

Boron Fertilization:

It’s better to apply it to the leaves, not the root. This will help to set the maximum number of fruits. Boron fertilization is especially necessary for cloudy, cool summers.

• Boric acid – approximately 0.35 ounces (10g) per 2.6 gallons (10 liters) of water.
• Buds and bloom stimulator: I have seen good results with Fox Farm Liquid Plant Fertilizer. 

Calcium Fertilization:

Before and after the fruit set, it’s recommended to do foliar feeding with calcium nitrate.

• Dissolve 1 ounce (20-25g) of the product in 2.6 gallons (10 liters) of water and spray the peppers with the solution.

Potassium Fertilizer:

In the fruit ripening phase, the pepper plant desperately needs potassium.

• Dilute wood ash with water in a ratio of 1:10 or 1:5.
• A solution of monophosphate 0.7 ounces (20g) per 2.6 gallons (10 liters) of water.
• Potassium nitrate – approximately 0.35 ounces (10g) per 1.3 gallons (5 liters) of water.
• Use potassium humate according to instructions.

Spraying

You can use spray Peppers for fertilization and in the fight against pests. In both cases, it’s crucial to follow the dosage of the preparations accurately.

A high concentration of substances can cause chemical burns on the leaves. As a result, the leaves may become covered with white spots.

If you’d rather not keep track of all the numbers and tables and prefer to keep things simple, then Fox Farm Liquid Plant Fertilizer is an excellent option for you. It works wonderfully for every growth stage and comes with an easy-to-follow, beginner-friendly schedule right on the package.

Pepper Diseases that Cause Leaves to Turn White 

Pepper leaves turning white can be caused by several diseases. White spots, streaks, and leaf tips can be symptoms of viruses and bacterial and fungal infections.

You’ll notice various symptoms based on the specific characteristics of each disease. It’s crucial to accurately identify these signs before launching a treatment plan.

1- Late Blight

Peppers can develop late blight with sharp temperature drops. This disease is particularly prevalent in late summer when high daytime temperatures shift to low nighttime ones.

The disease presents as brown spots on the plant, leading to the drying and dropping of leaves and, eventually, the death of the pepper plant.

To prevent this, maintain proper spacing when planting seedlings and enrich the soil with potassium fertilizers.

2- Gray or White Rot

Gray rot develops in high humidity conditions and air temperatures above 72 °F (22 °C). The disease infects the entire plant, visually presenting as a grayish-colored rot.

To prevent this disease, avoid planting bell pepper plants too close to each other.

If the leaf veins start to pale significantly, it could be due to the development of white rot. The disease presents as white spots, and over time, the plant dies.

The causes are dense planting, high humidity, and soil acidity. The solution is to reduce nitrogen fertilizers, moderate watering, and thin out the plants.

3- Cladosporium Leaf Spot

Due to humidity, light green spots may appear on the plant. This indicates that a fungal disease has attacked the bell pepper, causing Cladosporium leaf spot.

When infection appears, you need to reduce watering to decrease soil moisture. Also, as a preventive measure, the soil should be treated before planting the seedlings.

4- White Spot Disease

This disease initially attacks the root system of peppers; then, the leaves turn white.

If you do not treat the disease, it can negatively impact all the plants, infecting the shoots and already-formed fruits.

The disease develops due to intense heat and excessive moisture. Also, to prevent leaves from turning white, it’s important to maintain cleanliness in the garden.

For prevention, seedlings are treated with special products before planting.

5- Alternaria Leaf Spot

In this disease, the leaves become pale. Alternaria leaf spot emerges after night dew due to drought or temperature fluctuations.

You must prune off the infected plant parts and discard them to stop further spread. 

You can treat the soil with a fungicide solution to prevent the disease. You must dig up and discard severely infected pepper plants. 

6- Fusarium Wilt

This disease is challenging to detect in its early stages. The disease manifests during the fruit formation stage. It’s characterized by the leaves curling, yellowing, and wilting.

Warning! It’s impossible to cure an infected plant. It must be carefully dug up and burned. For prevention,  treat the pepper seeds with an organic fungicide before planting. 

7- Verticillium Wilt

This disease resembles a cucumber mosaic in its symptoms. The diseases are similar as they disrupt the normal development of the plant. Signs of infection include

• Leaves growing smaller and turning white;
• Growth of the plant halting;
• In the late stages, the plant sheds its leaves;
• If young seedlings are infected, they don’t form fruits;
• After a while, the lower leaves turn yellow.

8- Black Leg Disease

This disease develops due to a fungal infection in pepper seedlings. It can affect both seedlings and adult plants in greenhouses.

The fungus enters through the soil and leftover plants from the previous year or can be transferred with the seed material.

Dense planting of seedlings and insufficient aeration in the greenhouse are factors that contribute to the development of Black Leg.

The disease infects the plant stem, the leaves turn black, and the pepper plant dies. For prevention, inspecting plantings daily to detect infection in time is crucial.

When you detect Black Leg, treat the plants with a weak manganese solution and thin them out if needed.

9- Chlorosis

This leaf disease can affect peppers, shrubs, trees, and herbaceous plants. The disease manifests as a lack of chlorophyll.

This substance is needed for normal photosynthesis. You can identify the disease by the yellow and white leaves. The edges lighten, and specks form directly on the leaf blade.

10- Sclerotinia Disease

When infected, the plant suffers entirely, but primarily the root area. You can suspect sclerotinia if the leaves start turning white and large black spots are located in each center.

11- Powdery Mildew

If you are growing peppers in greenhouses, then they are susceptible to this disease.

The disease manifests as white powdery stuff all over the leaves. Irregular-shaped spots appear, and after some time, leaves fall off.

Prevention and Recommendations for Proper Pepper Care

Before you start treating my peppers, you must review the care I’m providing for the plants. These diseases often indicate that I haven’t properly cared for them.

If you want your plants to grow well and produce a good harvest, you must dedicate time to planting and nurturing them.

When Growing in the Greenhouse

Caring for bell peppers in open ground and in a greenhouse doesn’t differ much except for certain factors. Here are the growing rules in the greenhouse:

• Immediately dig up and burn any infected plant.
• Inspect the leaves and other parts of the plant daily.
• Control the humidity and temperature regime in the greenhouse.

When Growing in Open Ground

Here are some preventative measures for diseases of bell peppers in open ground:

• It’s important to periodically till the soil and add fertilizers.
• Planting seedlings according to a specific scheme and observing the timing of planting the seed material affect the subsequent development of the bush. The mature plant will have high immunity if done right at this stage.
• Regular monitoring of plant growth is key.
• It’s crucial to prepare the soil before planting the seedlings.

There are many reasons why the leaves of peppers turn white. That’s why it’s best to follow preventative measures.

Maintaining the appropriate microclimate, especially when growing in greenhouse conditions, is essential. 

Additionally, you should carefully choose a variety, as hybrids available today are resistant to different diseases. Making the right choice at this stage will help avoid many problems in the future.