What Causes Black Spots On Green Peppers?

You reach for a green pepper in the fridge and stop. There are dark spots on the skin. Maybe one. Maybe a cluster. The first question is whether something is wrong with the pepper, and the second is whether it is still safe to eat. Black spots on green peppers usually come from one of three things: a fungal infection, physical damage during growth or storage, or chilling injury from cold temperatures. Each one looks a little different, and each one carries a different answer about whether you should cut around it or throw the pepper away.

What Causes Black Spots On Green Peppers?

The most common cause is a fungal infection. Peppers have thin skins compared to many vegetables, and that skin is their main barrier against mold and rot. Once it is breached, fungi that are already present in soil, air, and storage environments can move in.

The two fungal problems you are most likely to see are Alternaria rot and anthracnose. Alternaria rot tends to show up as dark, sunken spots, often near the stem end or where the pepper was injured. The spots can grow and develop a fuzzy coating as the fungus matures. Anthracnose usually appears as circular, sunken lesions that darken over time and may produce tiny dark specks inside the sunken area. These specks are the fungal spores.

Both of these organisms are common in the environment. They do not require a contaminated kitchen or a dirty fridge to appear. A pepper can be carrying dormant fungal spores when you buy it, and the infection only becomes visible when conditions allow it to grow.

Physical damage is the second major cause. A bruise from a rough harvest, a nick from a knife, or pressure from other produce in a bag can break down plant cells. That damaged tissue turns dark as it oxidizes and dies. If fungi get into that wound, the spot will spread and soften. If not, you may see a firm, dark bruise that stays roughly the same size.

Chilling injury is the third. Green peppers are sensitive to cold. When they are stored below about 45°F (7°C) for more than a few days, their cell membranes begin to break down. The surface may develop pitted, dark areas that look like spots. This is not an infection at first, but the damaged tissue becomes much more vulnerable to fungal growth afterward.

Is It Mold, Bruising, or Cold Damage?

Telling these apart takes about ten seconds and your fingertips.

• Fungal rot: soft, mushy, or sunken. May have fuzz, dark specks, or a musty smell. The spot grows over time.
• Bruising: firm or only slightly soft. Dark but not sunken. Does not spread much. No fuzz or smell.
• Chilling injury: pitted, water-soaked-looking dark patches, often across a broad area rather than in one spot. The pepper may feel limp.

Fungal rot is the one that matters most for food safety. Bruising and chilling injury are quality problems, not contamination problems, unless mold has moved in afterward. That distinction is the whole reason a firm dark bruise and a soft fuzzy spot should be treated differently.

Can You Eat a Green Pepper With Black Spots?

If the spot is firm and clearly a bruise, you can cut it out with a wide margin and use the rest of the pepper. The same goes for mild chilling injury without any mold.

If the spot is soft, fuzzy, or smells off, throw the whole pepper away. This is not being overly cautious. Mold forms root-like threads called hyphae that extend well beyond the visible surface. The fuzzy part you can see is only the reproductive structure. The fungal network itself may already be spread through tissue that still looks normal. Cutting off the visible spot does not reliably remove the contamination.

Some molds also produce mycotoxins, which are compounds that can cause illness. Whether a specific mold on a specific pepper is producing mycotoxins is not something you can determine by looking at it. That uncertainty is the reason food safety guidance treats moldy soft produce as a discard, not a trim.

One clarification worth making: the dark spots themselves are not inherently toxic. A bruise is just damaged plant tissue. The concern is what the damage allows to grow, not the discoloration on its own.

How Does a Pepper Get a Fungal Infection?

Fungal spores are essentially everywhere. They travel on air, on soil, on hands, and on the surfaces of other produce. A pepper does not need to be mishandled to pick them up.

What determines whether an infection takes hold is the condition of the pepper’s skin and the environment around it. A pepper with an intact, dry skin is fairly resistant. A pepper with a small wound, a soft spot from chilling, or a water-soaked area gives fungi an entry point. Once inside, warm temperatures and moisture accelerate growth. That is why a pepper left in a warm, humid spot deteriorates faster than one kept cool and dry.

This is also why infections often start at the stem. The stem area is where the pepper was attached to the plant, and it is a natural weak point in the skin’s defenses. If you notice dark spots clustering near the stem, that is a common pattern for Alternaria rot specifically.

How Should You Store Green Peppers to Prevent Spots?

Storage is where you have the most control. The goal is to keep the pepper cool enough to slow fungal growth but not so cold that the cells are damaged.

Green peppers store best in the crisper drawer of a refrigerator, which typically runs slightly warmer and more humid than the rest of the fridge. The 45°F (7°C) threshold matters here. Below that, chilling injury becomes likely over several days. Above it, fungal growth speeds up. The crisper drawer is designed to sit in that middle range.

Keep the peppers dry. Moisture on the surface is one of the biggest contributors to fungal growth. If you wash peppers before storing, dry them thoroughly first, or better, wash them right before you use them. Do not store them in a sealed plastic bag with condensation building up inside.

Check them every day or two. A pepper with a small spot can be used quickly if you catch it early. The same pepper left another three days may be a total loss. Removing a visibly moldy pepper from the drawer also protects the ones around it, since fungal spores can spread to nearby produce.

Do not store peppers next to ethylene-producing fruits like apples, bananas, or tomatoes. Ethylene is a natural plant hormone that speeds up ripening and aging, which shortens the pepper’s usable window and makes it more vulnerable to spoilage.

Are Black Spots Ever a Sign of Something Else?

Occasionally, dark spots on peppers are caused by a bacterial infection rather than a fungus. Bacterial soft rot produces a wet, slimy texture and a distinct unpleasant odor. It spreads quickly and is generally a reason to discard the pepper.

In the garden, dark spots on growing peppers can also reflect a plant disease that affects the fruit before harvest. This is more of a gardening concern than a kitchen one, and the management is different from storage spoilage.

In practice, the exact organism behind a spot on a pepper in your fridge rarely matters for your decision. What matters is the texture and smell. Soft, wet, fuzzy, or foul-smelling means discard. Firm and dry means you can likely work around it.