4 Causes Of Black Spots On Pepper Plants (Stem, Joints, Fruits, Leaves)

Do you want to know the causes of black spots on the stems, joints, or fruits of your pepper plants? Here are a few possible conditions and diseases.

Peppers are some of the most widely cultivated plants in the world. These plants are mainly grown for their fruits, which have multiple uses in our diet. They are not very difficult to grow, so are oftentimes one of the main options of any gardening enthusiast.

Just like most plants, there are various diseases and pests that can attack pepper crops. To limit the effects and to avoid having our entire harvest destroyed, it is essential to identify the signs of any diseases or pest infestation at an early stage.

In this article, we will talk about several diseases of peppers and in particular the ones that cause the appearance of black spots and areas on various parts of the pepper plant.

Black Spots On The Stems And Joints Of Pepper Plants

If you’ve grown peppers, you have probably noticed the occurrence of black spots on the stems of some plants at some point. Usually, these dark areas appear in the upper part of the plant and particularly in the area of the joints, where the plant branches.

Is this normal? Stalk turning black on pepper plant. from r/gardening

Is this a disease and should I be worried about it?

If these black spots look similar to the ones in the picture above, you have nothing to worry about. That is not a disease but rather a natural response of the plant to certain stimuli.

It is not uncommon for some species of peppers to develop black spots on various areas of the stems or around the joints. It seems that two of the most common species of peppers in which this happens are bell peppers and jalapeños.

Are these black joints a fungal disease (maybe Fusarium)? I got it a couple months ago at Ace Hardware and it was fine, it was labeled as a Sriracha. Any advice is appreciated from r/HotPeppers

These black spots appear around the time when the plants reach maturity and even though the exact cause is not exactly known, the plant’s growth does not seem to be affected and the fruit is safe to eat.

Many believe that the appearance of these black or dark purple spots on the stem is just a plant’s response to stress factors, such as sudden temperature changes, and try to explain these dark areas due to an excessive accumulation of anthocyanin pigments.

Anthocyanins are natural pigments commonly found in various parts of plants including flowers, fruits, leaves, stems, and tubers. They are mainly responsible for giving red, purple, and blue colors but also have other functions such as attracting pollinators and preventing the oxidative damage of the plant (source).

Depending on the plant type and variety, anthocyanins are accumulated at various levels. When the pepper plants are stressed out, this pigment accumulates faster as a natural plant defense system, giving a purple to black color to parts of it.

But not only the pepper plant stems can turn black. This strange behavior is also frequently observed in the fruits of pepper plants.

Peppers Turning Black

Many times, pepper growers complain that whole fruits or parts of them turn black.

Why are some of my jalapenos getting this black stripe. from r/gardening

As you can see in the image above, a Reddit user posted a picture showing that the fruit of a jalapeños pepper has turned from green to black, or more precisely, a dark purple on about half of its surface.

This fruit’s weird color change is again attributed to the excessive accumulation of anthocyanin pigments that are found naturally in the plant and which normally have the role to give the fruit its yellow or red color when it ripens.

Although the fruit may no longer have the most pleasant look, it is 100% safe for consumption. Just the skin or portions of it have that dark color. The color of the flesh is not affected by this pigment accumulation.

Some fruits may even turn from green to almost black before ripening, before receiving the final color of the ripe fruit.

In conclusion, if you notice any dark purple to almost black spots on the stems, joints, or if the fruits of your pepper plants seem to turn black, without any additional signs of disease, you have no reasons to be worried about or to destroy your crop. This is not a disease, the plant will grow healthy, and the fruits are good for consumption.

Pepper Diseases That Cause Black Spots On Stems, Fruits, Or Leaves

Although you don’t always have to worry when black spots emerge on your pepper plants, there are also a number of diseases that produce black areas on stems, leaves, or the fruit of your peppers.

When you are dealing with a disease, it is very important to act quickly and apply a treatment in time to save your crop.

Below are some diseases that manifest through the appearance of spots or dark areas on various parts of pepper plants.

Bacterial Spot

Bacterial spot is one of the most destructive diseases of peppers. This condition is caused by a bacteria called Xanthomonas campestris pv. vesicatoria and it usually affects peppers and tomatoes.

In peppers, bacterial spot produces necrotic spots on leaves, can cause early leaf drop and spotting of stems. In severe cases, the fruit becomes unusable as well.

Anyone know what the black spots are on my pepper plant and how to get rid of it? from r/Peppers

The early signs of bacterial spot emerge first on the undersides of the leaves and initially look like small water-soaked areas. In time, the affected areas expand and get a dark brown to black color. On the top surface of the leaves, these points present a brown border around a beige center.

This disease can spread from one plant to another by splashing rain.

Blossom End Rot

Blossom end rot (BER) is a disorder in peppers and it affects the fruit.

This condition is caused by calcium deficiency and starts as a light green or yellow sunken spot and extends to a larger collapsed area that eventually turns black. BER can also be caused by irregular watering.

The affected areas are always at the bottom of the fruit, or slightly on the side on peppers, towards the bottom.

Persistent issue on jalapeños … blossom end rot ? Pest ? Any advice welcome… from r/Peppers

Besides peppers, blossom end rot is also common in tomatoes, eggplants, pumpkins, and squashes.

Anthracnose

Anthracnose is a fungal disease caused by a number of different species of fungi and is the most common fruit rot of pepper plants.

This condition starts with the appearance of water-soaked circular lesions on fruits. When it progresses, these areas become soft and sunken and the centers usually turn black.

Can anyone tell me why this keeps happening to my peppers before they ripen? Info in comments from r/gardening

Multiple lesions can occur in a single fruit and eventually will lead to its rot.

Even though the plant may have been infected for a long time with the pathological agents that cause this disease, the first signs usually appear on the fruits when they begin to ripen. Still, that’s not necessarily a rule as anthracnose can infect fruits at any stage.

Final Word

These are some of the most common conditions and diseases that cause black spots on the stems, leaves, joints, or on the fruits of pepper plants. As previously mentioned, some of these may be just natural reactions of plants to stressful conditions, while others are diseases caused by various fungi or unbalance.

I hope you found this article useful, and the next time you see black regions on your peppers you will know how to identify the cause.