This blog will discuss everything about Calcium in plants. If you are unaware of how important it is, you should give this blog a read! – Gro Indoor
Skip to content


All about Adding Calcium to Plants

by 09 Apr 2023

All about Adding Calcium to Plants

Have you ever wondered how essential Calcium is for plants? Well, this blog is going to answer all your queries related to plants and their calcium requirements.

Often underestimated, Calcium is an essential nutrient for plant growth. Usually, vital nutrients such as potassium, phosphorous, and nitrogen are the main ones that we focus on, and we forget that Calcium is equal and necessary.

Calcium plays a vital role in enduring a good and healthy plant life and growth. As we continue to research, it seems that this nutrient is more important than the primary three. Just as growers make the mistake of overdosing their plants with nitrogen and other nutrients, it is very typical and expected to do the same with Calcium.

So, in this blog, we will talk about the toxicity and deficiency of nutrients. Let's begin by discussing what Calcium can do to plants and how beneficial it is.

How Beneficial is Calcium for Plants?

Did you know that Calcium makes up to 4% of the earth's crust? Pretty cool, right? Then they must be of great importance in maintaining the structure of the plants. The development of a plant's cell wall is the most critical aspect, and Calcium helps it. The Calcium in our soil is one of the most important nutrients for plant growth. It helps new tissue development and also keeps cells stable, which means that without it, plants will wilt or even die!

Wondering how Calcium does this? The process is pretty simple. Plants have two vital transportation systems, namely phloem and xylem. You should know that nutrients from both of these systems can easily be removed, excluding Calcium.

Also, Calcium maintains membrane permeability, which allows an uninterrupted flow of all the sugars and nitrogen throughout the plant. It also makes the root structures strong by stimulating enzymes. Calcium is one nutrient that cannot travel; it is immobile.

Plants cannot move Calcium from one part of the plant to another. Why are we telling you this? Because all growers need to be aware of this nutrient's nature and provide a continuous supply of Calcium to their plants to get rid of any deficiency if there is any. Now that we know about the importance of Calcium's benefits let's discuss the best sources to obtain it from.

The Best Sources of Calcium for Plants

Just like humans and animals need a comprehensive source of nutrients, plants need them too. There are several different ways to add Calcium as a nutrient to the plants in your garden. After Calcium, an alternate is Gypsum, also known as calcium sulfate. Since it blends well with the clay particles and takes time to dissolve, it is a package ready and full of nutrients for your plants.

Another optimal choice is Lime, which is also known as calcium carbonate. Lime increases the alkalinity of the soil, which is best if you have a calcium deficiency. Lime takes time to activate, so you might not get the full and effective results immediately. So be patient with this nutrient.

If you are not a fan of adding nutrients, you can opt for natural alternatives such as eggshells and shell meals. They are slow absorbers and are found at many garden supplies stores. You can also make them at home. But for that, you need to first grind them finely in your blender before you add them to the soil.

Calcium-Magnesium Supplements

Cal-mag supplement is the best option of nutrients you can choose for your plants. The combination of Calcium and magnesium is crucial to the growth of plants as they are counted as secondary macronutrients (along with Sulphur).

In many cases, if a plant is deficient in Calcium, it is probably facing a magnesium deficiency. And to tackle this problem, many growers used Cal-Mag as a preventative measure. Cal-Mag is very important if you water your plants with treated water because Ca and Mg are usually found in waters with a hard pH level.

Suppose you live in areas with high humidity or temperature. In that case, you may face a deficiency of both nutrients, which is why Cal-Mag is a smarter choice. Combining both nutrients can provide the plants with a healthy and adequate dosage of nutrients across the surface. Make sure to cover all sides of the leaves while spraying so that you get optimal results.

Dealing with Calcium Toxicity

Calcium is not considered a toxic or harmful nutrient. But since excess of anything makes it negative, similar is the case with Calcium. An increased amount of Calcium in the soil can affect the intake of other nutrients, which can cause major nutrient deficiency.

For instance, excessive Calcium in oils makes it difficult for the roots to absorb zinc, potassium, magnesium, phosphorus, iron, copper, and boron. So, if you suspect that your plants may be facing deficiency in these nutrients, then you might want to check the amount of Calcium you are feeding to your plants. For further assistance, please read our guide on nutrient ratios.

The only way to find out is to check the water to detect this in a hydroponic setting. If you are noticing cloudiness or residue in your water, then your plant is facing calcium toxicity. If you notice the reservoir getting clouded in a hydroponic system, you can straightaway blame Calcium for that.

How to detect if Your Plant is Facing Calcium Deficiency?

To detect if your plant is facing calcium deficiency, you should check the upper and younger leaves and plants' overall growth. The symptoms of calcium deficiency are discoloration. You will notice that the tips of your leaves become slightly yellow, then brown and slowly turn black and die off.

Calcium is a micronutrient that largely contributes to plant growth, so when it's lacking in your garden, you can expect some serious consequences. When new leaves appear distorted or curled, they're likely a sign of calcium deficiency which will result in stunted development and failure to promote shoot formation.

  • Distortion of leaves and curling of tips.
  • New leaves will be deficient and stunted.
  • New leaves will have a very dark green color.
  • Very few lateral shoots.

How to Fix Calcium Deficiency?

The first step in treating calcium deficiency is to check the pH of the soil-based and hydroponic plants. If there is a pH imbalance, it will block the roots and make it difficult for the plant to absorb other essential nutrients. So, you should keep a regular check on the pH so that your plants don't face such situations.

The optimal pH range for most plants is 5.5 to 6.5. The nutrients present within this range, either in soil or water, are taken up easily by the plants' roots. But if the pH balance is shaken up, even if there are appropriate amounts of nutrients present in the soil, the plant won't absorb it.

Make Flushing an Essential Step

If you find out your calcium deficiency is due to a pH imbalance, then flushing the plant is the best choice. Always use freshwater to flush your plants and later start adding the nutrients as desired. The technique of flushing should balance your pH levels.

If you are flushing a soil-based plant, add at least 3 gallons of water for each growing media gallon. When flushing for hydroponics, remove the nutrient solution and replace it with clean water to bring the pH to its normal level.

Read our complete guide on flushing plants if you're still unsure. Check out our complete nutrient deficiency series at if you want to learn more about nutrient deficiencies.

Calcium for Plants in a Nutshell

Although calcium toxicity is rarer than calcium deficiency, it is advisable to check and test your plants before adding any nutrients to them. This would happen if you were overdosing on plant nutrients, and your petals will start falling off or discoloring.

We hope that these tips prove helpful to you and assist you in making a beautiful garden. Know that experts at are a call away (866-GRO-INDR) for guidance.

Sep 16th 2022
Prev Post
Next Post

Thanks for subscribing!

This email has been registered!

Shop the look

Choose Options

Edit Option
Back In Stock Notification
this is just a warning
Shopping Cart
0 items