Calcium deficiency in pepper plants can lead to blossom end rot, significantly affecting the fruits. This is caused by inadequate growing conditions or poor planting techniques.

Calcium Deficiency in Pepper Plants

Luckily, our gardening team will tell you how to save your pepper plants and restore their health in this complete guide. 

What Causes Calcium Deficiency in Pepper Plants?

The causes of calcium deficiency in pepper plants include planting your plants in acidic, sandy, or coarse soil. The soil can also contain insoluble forms of calcium that the plant can’t absorb. In some cases, this might be caused by inadequate fertilizing, uneven soil moisture, or bad growing conditions. 

– Soil Type

In most cases, the soil type is the real culprit behind your plants’ calcium deficiency. The soil colloids hold calcium, but it combines with the released hydrogen ions, causing the soil to become too acidic. 

Calcium combines with the bicarbonate ions to form calcium bicarbonate, which can’t be absorbed by plants. The presence of an insoluble form of calcium ions will impact the plant’s growth because it’s unable to absorb this nutrient.

The presence of calcium bicarbonate causes a general nutrient deficiency, affecting the growth of pepper plants. It also leads to bicarbonate root rot and turns the plants chlorotic, where the leaves don’t produce enough chlorophyll.

Most types of sandy and coarse soil are highly acidic, so they’re unable to hold enough nutrients, including calcium. In general, alkaline soil types contain more calcium. 

– Inadequate Fertilizing

Calcium and phosphorus are highly related to one another. This is why applying a phosphorus-rich fertilizer during the growth stage will boost your plants’ growth. However, in some cases, you might be over or under-fertilizing your pepper plants, and this leads to calcium deficiency. 

High phosphorus intake can affect the plant’s absorption of other nutrients, including calcium. This leads to calcium deficiency. Although phosphorus fertilizers are essential for increasing the plant’s ability to store energy, too much phosphorus in the soil will lead to several nutrient deficiencies. 

Causes Calcium Deficiency in Pepper Plants

At the same time, this nutrient deficiency can be caused by fertilizer runoff, which inhibits the plant from absorbing the essential nutrients. Phosphorus is needed to help the plant roots work efficiently. When there isn’t enough phosphorus, the plant won’t be able to absorb enough nutrients, including calcium. 

– Inadequate Moisture

Lack of moisture can inhibit your pepper plants from absorbing calcium, even when it’s present in the soil. The root system is unable to pull up nutrients because the soil is too dry, and eventually, your plant will suffer. 

This usually happens due to an improper watering schedule but can be caused by the type of soil itself. For example, this problem is more common in sandy soil with sharp drainage. It can also happen if you’re growing your plants in hydrophobic soil

At the same time, waterlogged soil will also affect calcium absorption. With too much moisture in the soil, the plant won’t be able to absorb enough nutrients. 

– Plant Stress

Growing your pepper plants in generally unfavorable conditions leads to plant stress and can affect the plant’s ability to absorb nutrients like calcium. For example, overcrowding your pepper plants deprives them of adequate air circulation and has them competing for nutrients. This also leads to root issues. 


How To Resolve Calcium Deficiency in Pepper Plants?

To resolve calcium deficiency in pepper plants, you can start by choosing the right soil and location to grow your plants in the first place. You should also assess the nutrients and water and fertilize your plants adequately to avoid nutrient deficiency. Adding extra calcium will also work. 

Resolving calcium deficiency depends on how long the problem has been persisting. If it’s a new issue, then adding a calcium-rich fertilizer and paying attention to the watering schedule will be enough to help the plant recover.

However, the burning of the leaves can’t be reversed, and you should wait for the new growth to see if your plant is recovering. If your plant shows signs of rot, you need to dig out the rotten roots because they won’t survive and might infect nearby plants. 

– Check the Soil

Nutrient deficiency symptoms can be pretty confusing, so you need to test the soil to ensure that your pepper plant suffers from calcium deficiency.

Resolve Calcium Deficiency in Pepper Plants

Taking a look at the different parts of the plant can help, but it will not tell you about what’s going on under the ground level. This is why you will need to use a professional testing kit or ask a professional gardener to test the soil for you and check the levels of all the nutrients that your pepper plants need to thrive. 

Checking the soil can help you determine if the ground is adequate for growing peppers. You’ll test all the available nutrients, so you might want to pick another location to grow your plants and avoid future problems. 

– Space Your Plants Adequately

This tip is excellent to follow as you’re growing new pepper plants. Pepper plants should be spaced about 18 inches apart to allow the roots to branch. However, it’s recommended to space them closer if the temperature is below 60 degrees Fahrenheit. 

When pepper plants are planted too close to each other, they struggle to access essential nutrients like calcium. This will lead to calcium deficiency in the long run.

Gardeners need to fertilize their pepper plants during summer if they’re too close to one another. For the next growing season, you might want to pick a different planting location where they can grow properly. 

– Control Growing Conditions

The growing conditions can affect how well your plant is able to absorb calcium from the soil and water. For example, the water might contain too many salts that inhibit the plant from absorbing enough calcium.

At the same time, too much humidity can affect the transpiration process and, eventually, reduce the calcium levels in your pepper plants. 

It’s best to grow your pepper plants in moderately humid conditions to guarantee that they’re able to access all nutrients efficiently.

This problem is more common in greenhouse plants where the humidity levels can get too high. Proper spacing and having well-draining floors will help reduce the humidity if you grow your pepper plants in a grow room. 

– Add More Calcium

Amending the soil can be the answer if the soil is particularly poor in calcium. This can be done by adding an adequate type of calcium nitrate or calcium chloride-rich fertilizer to your pepper plants. It’s best done with new plants about two weeks after the seeds have sprouted, as this will aid in future fruit development. 

If you want to skip chemical fertilizers, you can enrich your soil with more calcium by adding bone meal, eggshells, dolomite lime, or gypsum.

These are all organic alternatives that can help amend the soil if the pepper plant has low calcium levels. However, you should make sure that you’re not adding too much calcium, as this will affect the absorption of other essential nutrients. 

– Choose Your Fertilizer Carefully

You might think that adding fertilizer will be a good solution if your pepper plant is showing calcium deficiency symptoms. However, an excessive amount of nitrogen-rich fertilizer can actually have an adverse effect. 

Nitrogen fertilizers help amend the soil but can stress pepper plants during periods of drought. In addition, high nitrogen rates from manure or chemical fertilizers will impact the plant’s ability to absorb calcium and will stunt its growth. 

The fastest way to deal with a calcium deficiency is to add a liquid fertilizer by spraying it onto the leaves. Using a spray fertilizer that contains calcium chloride or calcium nitrate can be combined with other calcium-amending methods, and it allows the leaves to directly absorb the nutrient. 

– Water Your Plant Regularly

Transpiration issues might be the culprit behind the calcium deficiency problem. Transpiration or the loss of water through the leaves of the pepper plant will be impacted by the lower level of calcium. This means that the plant won’t be able to pull up the water from the ground, and it will wilt and wither. 

Ensure that the soil isn’t too dry, as the lack of watering can be why the plant isn’t pulling any nutrients up. Pepper plants need to be watered when the soil feels a little dry.

This can significantly vary depending on the weather, so you might need to water your plant every day during the hot summer months and less often as the temperature drops. 

– Assess the Other Nutrient Levels

As you try to amend your soil to improve the levels of calcium, you need to make sure that you’re not leaving any other nutrients out. Calcium binds with other micro and macronutrients through ionization, and the lack of these nutrients can affect its absorption

This is why you must regularly test the soil and water for phosphorus, potassium, zinc, magnesium, and iron.

One nutrient out of balance will affect the absorption of others, eventually killing your plant. As a matter of fact, the deficiency in one nutrient usually starts a chain reaction that becomes very difficult to control. 

The plant will struggle to absorb one nutrient, and this affects its ability to absorb others that might be present in the soil. Moreover, some deficiencies, like boron and magnesium deficiencies, have the same symptoms as calcium deficiency.

Therefore, in most cases, your plant will be suffering from multiple nutrient deficiencies at the same time, and these deficiencies will have a bigger impact on your pepper plant. 

– Grow Your Pepper Plants in a Greenhouse

Greenhouse planting allows you to have more control over the growing conditions of your plants in general. You can extend the growing season, amend the growing conditions, and customize the environment according to the needs of your plant. 

Calcium Deficiency in Pepper Plants Symptoms

So if you don’t have enough space to grow your pepper plants, or the conditions aren’t that favorable, a greenhouse solution will work for you. Moreover, greenhouse planting will protect your pepper plants from pests and diseases that can be easily transferred from other plants in the garden. 


Calcium deficiency in plants has several symptoms, including withering leaves, burnt leaves, stunted growth, and rot signs.

Luckily, several tips can help you fix this problem. 

  • Choose the best location for growing your pepper plant by testing the soil. If the soil conditions aren’t favorable, you can either try to amend it or consider growing your plant in a greenhouse. 
  • Always test the soil for other nutrient deficiencies, and use nitrogen-rich fertilizers wisely. 
  • Space your pepper plants properly to allow the roots to access water and nutrients. You should also water them regularly to keep them well-hydrated. 

After reading our team’s advice in the guide above, we’re sure that you can now protect your future pepper plant harvest from any calcium deficiency-related issues. 

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