Your peppers can sometimes turn black (or dark purple) as they ripen, but beware, as sudden darkening may indicate something wrong with your plant.
It may be challenging to pinpoint an exact problem for the darkening, especially if you are a novice pepper gardener.
Read on to find out how to diagnose each problem and ways to fix them.
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What Causes Peppers to Turn Black? (Reasons & Fixes)
Novice gardeners are bewildered when they find their beautiful pepper fruits turning black after 2-3 months of hard work.
While peppers naturally turn green to red, some begin turning black or create dark, mushy spots from different problems.
Although immensely shocking, witnessing this drastic transformation is not unusual with pepper plants.
Here are some probable causes for pepper turning black and their fixes.
1. Natural Process
Typical to fruiting plants, peppers change color and texture once they ripen before decaying.
A fully grown pepper would look swollen and glossy, indicating the harvest time. The fruits begin to over-ripen as they absorb more sunlight and nutrients, gradually changing color.
You would notice black or dark purple shades appearing throughout the fruit, but they are still edible.
Some pepper varieties, such as Chinese 5-Color, start as a dark purple before retaining its original color.
Similarly, some bell peppers attain dark purple coloration while turning red, which may look black at first instance.
Therefore, you should be wary about the type of peppers growing in your garden to understand how they usually change color.
2. Blossom End Root
Blossom-end rot, also known as a water-soaked spot, is a blackening disorder at the bottom of pepper fruits.
However, it is not entirely a rot but a calcium deficiency caused by drought, followed by over-watering.
The affected plants will develop tanned, brown-to-black spots at the bottom of the fruit.
You would mostly witness it in spring when the fruits are first developing.
Blossom-end rot is irreversible, but you can still consume the fruit.
- Remove the affected fruit and discard them safely.
- Next, fix the calcium level in the soil by amending it with lime or calcium carbonate to raise the pH.
- As an organic approach, adding eggshells, seaweed, wood ash, and bone meal to the soil helps add calcium.
- Resume watering the plant every 2-3 days in spring and almost every day during the hot summer.
If your pepper plant leaves are turning yellow, learn about the causes and solutions.
3. Excess Sunlight (Scalding)
Pepper plants need strong sunlight to thrive and bear healthy fruiting, but exposing the fruits to direct sunlight may be a bad idea.
When exposed to direct sunlight, these pepper fruits may develop sun scalding from excess UV radiation and heat.
Early sun scalding signs might include black, brown, or bleached spots around the pepper fruit’s skin.
Those exposed to direct sunlight all day long may even produce darker skins with soft texture, which can be alarming.
- Execute crop rotation, sanitation, regular pruning, and fertilizer use.
- Cover exposed fruits with a bright, lightweight material, such as shade cloth, especially in high summer.
- Grow peppers close to each other, about a foot, to share shade among the plants.
- Harvest the fruit as soon as they mature, usually mid to late summer.
4. Cold Stress
Peppers are native to tropical South America, where they thrive in temperatures between 70-90°F, depending on the variety.
However, the plant may wither, and fruiting may discolor if the temperature drops below 32°F, usually in fall.
Therefore, it is essential to consider location, time of the year, and temperature when growing peppers in the garden, as they are more susceptible to weather change.
Providing ample warm temperatures ensures healthy plant growth and fruiting in summer.
Varieties such as jalapenos and bell peppers are more prone to cold stress, where they may begin discoloring when the temperature drops below 46°F.
Pepper fruits suffering from frost damage for a few hours can survive and recover, but severely damaged fruits will die.
- Move potted pepper plants indoors under LED grow lights to provide warmer surroundings.
- Choose a garden location that receives 6 hours or more sunlight daily, usually a south-facing window.
- Harvest the produce by early fall to prevent the risk of cold stress.
- Grow your pepper plants in the greenhouse when attempting to grow in fall or winter.
5. Disease and Pests
Be wary of black spots on pepper fruits, which may indicate the grave problem of bacterial spot infection.
The bacterial spot may spread from infected plants when the weather is warm and humid. Similarly, the pepper weevil is a pest that infests pepper leaves and thrives in warm, humid weather.
Disease and pest infestation are easy to identify, with tiny black spots that appear around the fruit.
Sometimes, heavily pest-infested pepper will produce large cankers, which indicates pest bites.
- Start with disposing of the plant and fruits with the heavy infestation before it spreads to the accompanying plant.
- Spray the remaining plants with a solution of baking soda, vegetable oil, and liquid soap to remove traces of bacterial spots.
- Spraying insecticides may help treat early pepper weevil infestation.
- As a precaution, select disease and pest-resistant pepper varieties to grow in your plant.
- Alternatively, treat pepper seeds with hot water or calcium hypochlorite to kill the pathogen before sowing.
6. Nutrient Deficiencies
Pepper fruits producing ugly black spots in the growing stage may indicate a nutrient deficiency.
The lack of phosphorus or inability to process the nutrients may produce a black spot on the fruit skin.
It is often accompanied by decreased fruit quality and poor bending stem, which indicates severe phosphorus deficiency.
However, pepper plants would equally require potassium during the growth stage for healthy fruiting.
Therefore, you should fertilize your pepper plant with the correct formulated solution.
- Apply formulation solutions like 11-11-40 or 12-15-30 every month in spring and summer.
- You can also offer a diluted solution every week to boost fruiting in summer but beware of over-fertilizing the plant.
- Alternatively, add bone meal and rock phosphate in the soil to correct the pH level and allow the plant to absorb phosphorus nutrients quickly.
If you wish to know about hottest peppers in the world, get a list of top 10 here!
Peppers are easy-to-maintain crops that you can quickly grow in your backyard or containers.
However, be wary of optimal growing conditions and regular care to get healthy pepper fruits in spring and summer.
Follow this guide to diagnose various problems with your pepper plant and ways to fix them quickly.