Why Are My Peppers Turning Black?

Why Are My Peppers Turning Black

One of the many reasons gardeners love peppers is their wide array of brightly colored varieties. The fruits can be sweet or spicy, and make great additions to salads and almost any home-cooked dishes.

However, a novice gardener might feel frustrated when these supposedly colorful fruits start turning black.

Bell peppers are usually green, red, yellow, or orange, depending on their level of ripeness. There are also varieties, such as Jalapeños, that naturally turn black or dark purple when the fruits start to ripen. 

However, it is possible that diseases, pest infestations, or extreme weather conditions are the culprits if your peppers are turning black. Common signs to look out for are black spots appearing on the fruit, stems, and leaves. If your pepper starts developing a leathery or soft skin, this is also a red flag.

Why are my peppers turning black? – Common causes

There are many possible reasons that your bell peppers are suddenly turning black, as explained in detail below:

1. Natural ripening process

All crops go through a natural ripening and aging process, each with its own distinct traits in terms of texture, taste, and color. In the case of peppers, some varieties naturally turn black as they ripen. For example, Jalapeños change color from green to black once they reach full maturity. Some pepper varieties might also turn dark purple, and this is completely normal.

2. Nutrient deficiencies

Green peppers can turn black if they are nutrient-deficient, particularly in phosphorus and calcium. While nitrogen provides the crops with their lush green leaves, phosphorus and calcium support the flowering and fruiting process. Hence, these minerals are important for the plant to produce good yields. 

If your peppers are not receiving enough minerals, their fruits may begin to develop ugly black spots on their skin. The deficiency will also affect the fruit quality, stem and root development, and the plant’s ability to fight diseases. Hence, if you notice your peppers turning black, you might need to consider fertilizers to boost the plants’ health.

3. Sunscald

Like many plants, peppers thrive in full sunlight, and there are varieties that turn black or dark purple as a defense mechanism against the sun’s harmful UV rays. You might also notice the leaves developing some purple streaks, which should be normal in most cases.

However, too much exposure can have dangerous consequences. Your peppers can develop sunscald, and aside from turning black, some varieties might also develop brown or white spots where the skin is damaged by the intense sunlight. Instead of lush green, you will notice the foliage developing white streaks and the burnt fruits might crack or split open. It is also possible for the burnt areas to rot and become infected with bacteria or fungi.

Although sunscalded peppers are cosmetically unappealing, they are still good to eat. If you want your peppers to maintain their healthy, bright colors, make sure to limit your plants’ exposure to full sunlight, especially during periods of extreme heat.

4. Exposure to cold temperatures

Most pepper varieties grow well in temperatures between 65 and 80 degrees Fahrenheit; anything outside this range can affect the plant’s flowering and fruiting process. Blackening or dark purple discolorations are very common during the cold seasons, but this does not mean the fruits are going bad. Jalapeños, in particular, are prone to turning black or purple during winter which should be normal.

However, extremely cold temperatures below 46 degrees Fahrenheit can damage most pepper fruits. Freezing can also cause a stunted appearance in the fruits and can cause the leaves to wilt. Hence, it is highly recommended to grow your peppers inside a greenhouse during winter. You can also use frost protection blankets or any container to protect your fruits from frost, strong wind, and snow.

5. Black bell pepper varieties

Certain bell pepper varieties normally turn black or dark purple at maturity. For example, Jalapeños turn dark purple as part of their ripening process, before finally changing into a bright red color. Black peppercorn, another variety of black bell pepper, also turns black once it reaches its mature state. In most cases, these color changes should not cause any serious concern.

6. Plant diseases

Certain diseases can cause bell pepper fruits and stems to develop black spots. In this case, the affected fruits become unsafe for consumption. Some of the common diseases that cause black discolorations are as follows:

  • Fungal infections, which include Anthracnose and Phytophthora blight. Fungal diseases usually cause the appearance of black cankers and black rings on the fruits.
  • Viral diseases, which cause light-colored rings on the affected fruits. The plants also develop black spots on the fruits, stems, and leaves, leading to wilting and death.
  • Bacterial infections, which are often a result of intercropping. Plants that are exposed to elevated temperatures and humid environments are at risk of developing this disease.  

7. Blossom end rot

Blossom end rot is a result of nutritional deficiency and inappropriate soil conditions for the pepper plants. Novice gardeners might mistake blossom end rot as a type of rot, but it actually is not. The condition is related to problems with calcium uptake, low soil calcium, low soil pH, drought conditions, and improper watering. Affected fruits usually develop large brown or black spots on the bottom. 

During the growing season, you might start to notice light green or yellow spots. Soon, these spots become dark, leathery lesions, which make the fruits aesthetically unappealing. 

Blossom end rot in peppers is not bacterial, viral, or fungal-related, so it is safe to cut away the affected spot and eat the rest of the fruit. 

8. Pest infestation

There are many types of garden pests that damage pepper plants, at all stages of growth. The most common ones are aphids, thrips, whiteflies, and pepper weevils. These insects lay their eggs and hatch their larvae inside the fruit, causing the appearance of black spots. As they continue to reproduce and consume the fruit, these creepy crawlies leave behind by-products and feces which look like coffee grounds or sawdust. Without proper intervention, your plants will likely suffer from leaf loss, stunted growth, and damage to the stems and fruits. 

9. Exposure to artificial herbicides

Certain synthetic chemicals used to control weeds might do more harm than good in your garden. The chemical contents of herbicides are known to cause malformations and the development of black spots on pepper fruits, leaves, and stems. For this reason, it is recommended that you use compost and mulch instead to deter weeds and improve your soil’s fertility.  

Can you eat a pepper with black spots?

Peppers with black spots are usually safe to eat, but might be unappealing to some people. In this case, you can cut away the blemished areas and eat the rest of the fruit. However, some black spots might signal spoilage or crop disease, in which case it is better to discard the entire fruit for your safety.

How to prevent peppers from turning black

Prevention is always better than cure, and that applies to crops, too. Black spots on peppers can be unappealing, but there are certain tips you can follow to prevent your fruits from turning black.

1. Basic maintenance

Providing your plants with favorable growing conditions goes a long way in preventing the appearance of black cankers. This includes using a well-draining soil, proper watering, correct fertilizer, and protecting your plants from extreme weather conditions. It is also best to use soil test kits to ensure that the soil has the right pH for your peppers to grow happily.

2. Use drip irrigation

Drip irrigation ensures that your plants are watered close to the ground, without splashing water on the leaves. Keeping foliage wet for extended periods can invite fungal spores and other diseases that can cause damage and stunted growth. 

3. Use natural pesticides

Neem oil can do wonders when it comes to eradicating pests in plants. It is also organic and safe for humans and other beneficial insects, unlike artificial pesticides. 

4. Consider disease-resistant pepper varieties

Disease-resistant varieties of pepper will help you grow good-quality fruits in your home garden. Make sure to do your research and read the seed package labels to know whether your chosen plants are disease-resistant. 

5. Crop switching

Switching your garden crops annually will help prevent certain diseases in your bell peppers. Additionally, through this practice, you can protect the soil from nutrient depletion and degradation.

6. Remove infected plants

Plant diseases such as fungal infections can spread easily to other plants. Hence, you must remove any infected crops from your garden to avoid affecting your other, healthy plants. It is also not advisable to compost the diseased plant remains, since bacteria and spores can survive in the soil and thus continue to affect your garden plants.

Wrapping it up

There are many possible reasons that your peppers may develop black discolorations. Some pepper varieties will naturally turn black during the ripening process. However, the appearance of black spots or rings could also be indicative of disease, pest infestation, improper watering, sunscald, or a lack of nutrients. 

Unless the black spots are caused by a plant disease, most peppers that have turned black should be safe to consume. The only downside is that the affected fruits might look unappealing, but rest assured, the black blemishes will not affect the taste and nutrient content of your peppers. 

Image: istockphoto.com / Phanompai