Peppers are a staple of backyard gardens. Their multicolored fruits (yes peppers are actually fruits) add a nice splash of color to garden beds with their green, red, orange and yellow exteriors. However, coming across a black colored pepper in the garden will leave many gardeners shocked and bewildered. So why are some peppers turning black? I decided to find out.
So what causes peppers to turn black? When peppers turn black, it is usually just a phase in the ripening process. While some peppers simply change from green to red, other peppers will start out green then begin to turn black and then finally red, orange or yellow.
While peppers commonly turn black during the ripening process, peppers can also turn black for a number of other reasons as well. If your peppers are turning black but show no sign of changing, there is likely another reason as to why your peppers are turning black.
Changing Environment:
Peppers love warm weather. But late in the growing season when the temperatures begin to fall, the cooler weather can have some adverse effects on your peppers. A drastic decrease in temperature can cause exposed areas of the peppers growing on the plant to turn black. Although this can be an eyesore, it has no effect on the pepper’s taste.
There are a few ways to combat this type of blackening. One way is to harvest your peppers before the temperature drops too much. Keep an eye on the forecast. If the temperature drops by more than 30° F (16.8° C) within a few days, harvest any peppers you can before the cooler temperatures begin to turn them black.
If you have peppers that aren’t ready for harvest or you simply just don’t want to harvest any of your peppers yet, another option is to cover your pepper plants with a frost protection blanket. This will protect your peppers from the cooler temperatures as well as from snow, wind and frost. Alternatively, you can cover your pepper plants with just about anything (ex. Cardboard box or plastic container) however, frost protection blankets provide much better insulation while still allowing your plants to breathe.
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While the blackness caused by cooler temperatures has little to no effect on the pepper’s taste, covering up your pepper plants before cooler temperatures arrive is still a good idea. Most pepper plants are not very frost tolerant and even a light frost can severely damage or even outright kill your pepper plants.
Nutrient Deficiencies:
Peppers that are turning black and can also be a symptom of a nutrient deficiency. When pepper plants enter the flowering and fruiting stage of their life cycle, they rely a lot more on phosphorous. If the pepper plants are not receiving enough phosphorus, the fruits can begin to turn black.
In addition to giving your peppers some ugly black spots on their skin, a lack of phosphorus can also give your pepper plants plenty of other unwanted side effects as well. These side effects include decreases in fruit quality, decreased disease resistance and also poor stem and root development. Therefore, the blackening of your peppers may be a signal of far greater problems.
One way to correct this problem is to add some phosphorus based fertilizers to the soil around your pepper plants. Bone meal and rock phosphate are great examples of all natural, organic phosphorus based fertilizers. While both fertilizers work great in the garden, I would recommend bone meal in this instance as bone meal is known to work faster and allow the pepper plant to absorb the phosphorus nutrients easier thus solving the nutrient deficiency problem quicker.
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Plant Diseases:

I really found this article and the article on grasshoppers/pests helpful! We live in an apartment and keep our plants in pots. We tried to grow beans and peppers but none made it. I’m guessing it was lack of nutrition in the pots so reading about the different nutrients peppers need was key! Do you have any other tips for growing veggies in pots? Thanks so much!
Sorry I didn’t read the rest of your comment until just now. As for the plants you are growing in pots, make sure you using a good seed starting mix when starting vegetables and beans in pots. Seed starting mix is like potting mix but is specifically adapted for starting seedlings in pots. Using garden soil or even potting mix my prevent your seeds from adequately sprouting. Hope that helps!