Skip to Content

How to Add Calcium to Soil (Plus 7 Types to Consider)

How to Add Calcium to Soil (Plus 7 Types to Consider)

Share this post:

Disclaimer: Some links found on this page might be affiliate links. If you click an affiliate link and make a purchase, I might earn a commission. As an Amazon Associate I earn from qualifying purchases.

Soil is made up of organic matter, minerals, gases, liquids, and organisms, and it has several important functions, including providing the conditions for plants to grow. One of the macronutrients in soil is calcium, which is important for plant growth.

It also helps to make plants less at risk for diseases and pests. Your soil needs the right balance of calcium to create the ideal environment for your plants, so it is important to learn how to do this.

You can find out if our soil needs calcium by conducting a professional soil test. This test will analyze the calcium level as well as the pH of your soil so that you know what your soil is lacking.

You will be able to find out exactly what macronutrients you need to add to your soil for optimal conditions.

Why Do Plants Need Calcium?

Plants are living things, and they require certain nutrients so that they can survive. There are nine macronutrients and eleven micronutrients.

Plants need larger quantities of macronutrients as well as water and sunlight for their survival.

The macronutrients that plants need include the following:

  • Calcium
  • Carbon
  • Nitrogen
  • Hydrogen
  • Oxygen
  • Phosphorous
  • Potassium
  • Sulfur
  • Magnesium

Calcium is important to help regulate nutrient transport and support enzyme function. In addition, it helps with different cell functions and allows for fruit and flower formation.

If the soil is lacking calcium, you will need to supplement it because your plants can develop a calcium deficiency.

This can present itself as slow growth or even signs of cell death. It is best to check the levels in your soil and make sure that you have the right amount of calcium present.

Why You Should Test Your Soil

When you determine whether to add calcium to your soil, you are not looking to have a particular level because the calcium absorption is called the Cation Exchange Capacity (CEC). This is a measure of the ability of your soil to absorb and hold calcium in cations.

The CEC level is what will let you know whether or not your plant can get enough calcium from your soil. In addition, the pH level of your soil plays a role because soil with a higher pH level normally has more calcium available for plant absorption.

For this reason, you need to have a professional soil test done. This test will tell you the exact CEC level of your soil, which will let you know how your soil is composed.

For instance, soil with higher CEC has more organic matter and clay, which means that it can hold water and nutrients well. If your soil has low CEC, it is sandy and lacks nutrients because they leach out of the soil more quickly.

Once you know the CEC results, you will know what you need to add to your soil, including how much calcium. You may need to add organic matter, or you may need to add lime to lower the acidity or add sulfur to raise the acidity level.

The key is to adjust the CEC and pH to ensure that your plants will have the right amount of calcium available.

How to Look for Signs of Calcium Deficiency in Your Plants

Because calcium strengthens the cell walls in plants, a calcium deficiency causes them to weaken. You will notice stunted growth or weakness, and you will also see the new tips of leaves growing in a deformed fashion by curling up.

In addition, you may see spotting or scorching on the leaves, along with a lack of bud growth.

The worst effects of calcium deficiency take place on the roots. Root extension is dependent on calcium, and it also protects plant roots from some diseases.

Roots can become discolored or stunted and leak those nutrients needed for growth. The roots might become slimy and thin, and they may turn black or brown.

There are other signs of calcium deficiency, including burnt leaf tips, chlorosis, and fruit damage. An example of fruit damage is blossom end rot, which can occur in tomatoes. Bitter pits in apples is another sign.

When you see the widespread damage that occurs in plants that grow in soil that is lacking calcium, you start to realize just how important the correct calcium levels are for plants to survive.

How to Add Calcium to Your Soil

Once you have done your professional soil test, you will know exactly what nutrients your soil is lacking as well as the pH level of your soil.

If you haven’t run a test, but have observed the symptoms above, you can also add calcium, especially if you are certain that your plants are suffering from a calcium deficiency.

There are different products available for this, so you should use what is best for your soil.

Different Calcium Fertilizers

To determine which calcium fertilizer is best for your soil, you will need to know the pH level of your soil and choose based on the types of plants that you are growing.

Take a look at the following calcium fertilizers:

1 – Foliar Sprays

Foliar sprays include calcium acetate, calcium nitrate, and calcium chloride. These sprays are designed to spray the plants because they can absorb the nutrients more efficiently through their leaves than they do through their roots.

This will not raise the pH level of your soil, so it is a good idea if you just need to make sure that your plants are getting more calcium. You might use this method if you have observed the calcium deficiency in your plants, but haven’t tested the soil.

2 – Lime

Mined limestone will yield calcium carbonate, and it can boost your soil’s calcium content.

You need to do the test first because lime can also raise the pH of your soil, which will make it less acidic. This works well as long as the pH levels aren’t overly affected by it.

Dolomite Lime is a form of calcium carbonate, and in addition to adding calcium to your soil, it has magnesium carbonate in it and can raise the pH if your soil has lower magnesium.

You should not use this type of lime if your soil has high magnesium levels.

3 – Gypsum

Gypsum is calcium sulfate, and it quickly adds calcium to your soil. It has a low CEC and will not change the pH of your soil.

4 – Oyster Shell or Clam Shell

This product is also called calcium carbonate, and it is a good source of calcium. This is not a quick fix, as the shells take a few years to become an effective source of calcium, and it will raise your soil pH level over time.

5 – Wood Ashes

Wood ashes are another calcium carbonate, and they will add calcium to your soil. They will raise the pH as well.

However, if you need to raise the pH of your soil, lime is far more effective and will also raise the calcium levels.

6 – Soft Rock

Soft rock can be called colloidal phosphate, calcium oxide, or rock phosphate. It releases calcium to the soil over time, and it is less soluble than lime. It raises the pH a little bit as well.

7 – Bone meal

Bone meal is a high phosphate fertilizer, and it is released more slowly than lime. It is also less soluble. If you want to raise the pH slowly, this is a good product. It can help bulbs and root crops.

Final Thoughts

It is important that your soil has the right calcium levels for plants to survive and do well. Plants need nutrients to survive, and calcium is one of the more important macronutrients for them.

The best way to find out the contents of your soil is to conduct a professional soil test. You can also do an at home soil test with a kit, but a professional test will yield the most accurate results.

When you add calcium to your soil, you should make sure that you aren’t throwing the pH levels off too much. Some products can increase the pH quite a bit, so you should avoid those unless you need to adjust the pH.

If your plants are showing signs of a calcium deficiency, you might want to use a foliar spray to quickly help them get the calcium they need. Plants absorb nutrients more quickly through their leaves, so this will help them quickly.

If you are following the results of your professional soil test, you can use another slow acting method. There are people who suggest that egg shells is another calcium alternative, but the reality is that egg shells decompose too slowly to have much impact.

Try lime or bone meal, or use any of the methods listed above. This will improve the calcium levels in your soil and help your plants get back on track.

Calcium is an important nutrient for your soil, and plants rely on it for healthy growth. Make sure that you are giving your plants everything they need by adding the right amount of calcium to your soil.

Share this post: