How to Add Calcium to Soil: How Do I Add Calcium to my Garden?

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You might wonder why calcium is needed in garden soil. Isn’t it just used to build strong bones and teeth? But it may be to your surprise, but calcium is also critical for the bones of your plants, commonly known as the cell walls.

Similarly, like animals and people, plants too can suffer from calcium deficiency. Therefore, it is very vital to ensure the healthy growth of your plants.

Calcium and good gardening soil are linked. Just as humans need fluids to carry nutrients throughout their body, likewise water is required to carry calcium to all parts of the plant. Adding not enough water leads to a calcium-deficient plant.

On the other hand, if sufficient water is added, but the problems persist, it is time to ask yourself how you can add calcium in soil to make it reach a sufficient level.

how to add calcium to soil
why calcium is essential in gardening soil?

But first, let’s understand why calcium is essential in gardening soil.

Why is Calcium Essential in Gardening Soil?

Gardening soil comprises of four macronutrients, and one of them is calcium. Calcium is vital for plant growth and also makes them less susceptible to pests and diseases. But when it comes to calcium, it does not mean that more is better.

Adding too much calcium in the soil can lead to a high pH level, which makes the gardening soil too alkaline. Having excessive levels of alkaline in gardening soil can affect the absorption of the macronutrients encompassed in gardening fertilizers.

Although most pre-packed gardening soils include sufficient amounts of calcium, at times it may be essential to add extra calcium to your gardening soil. The reason for this is that there are many plants that require more calcium than the rest.

Not providing adequate calcium to such plants will give them less than ideal growing conditions or may not provide the necessary calcium to help them thrive and grow.

How to Determine If You Need to Add Calcium in Soil?

The best way to determine whether you need to add calcium to your garden soil is through conducting a professional soil test. It’s different from the pH test that one can perform at home.

A professional soil test helps to examine both the pH and calcium levels of your garden soil. Conducting a professional soil test will help you determine what exactly to add to your soil and in what quantity.

Remember that in a living plant, calcium travels upward from the roots throughout the plant via water transpiration. That is why adequate watering of the plants is always critical. Once calcium is moved to its ultimate destination, such as young or new tissues and tips, it’ll stay put. 

How Calcium Benefits Plants?

Following are the few benefits provided to plants through calcium:

  • Calcium is vital for the formation of the stem, roots, and new growth in plants.
  • The nutrient forms calcium pectate that plants utilize to build cell walls and membranes.
  • Subsequently, calcium helps to provide rigidity to plants.
  • Calcium is used by plants to create carbohydrates like starch and cellulose.
  • Calcium significantly benefits garden soil by improving the soil structure and allowing soil particles to stick together.

Which Plants Need Calcium?

Although all plants require calcium for optimal growth, few plants are more responsive to it as opposed to others.The following plants tend to grow and thrive well by adding sufficient calcium to their nutritional regimen:

How Calcium Affects Plants?

These are the following ways in which calcium affects gardening soil and lead to better growth of plants.

  • To build strong cell walls to keep the plant straight 
  • Acts as a transporter for other minerals 
  • It counters acts with organic acids and alkali salts
  • Calcium acts as a vitamin pill for your garden 
  • Calcium deficiency may cause stunted growth in tissues, new leaves, and result in brown spots from edge to the centre of the leaves. 
  • Receiving accommodate amount of calcium is necessary for plants as vegetables may spoil, e.g. rot in tomatoes or black heart in celery as a signal for calcium in the soil.

How to Determine Optimal level of Calcium in Garden Soil 

The calcium level of soil doesn’t interpret how much calcium is getting absorbed by the plants. CEC – Cation Exchange Capacity is a crucial term for calcium absorption. CEC is the ability of the soil to absorb and hold nutrients.

Soil acts as a storage of nutrients for plants such as calcium and magnesium in the form of cations. Therefore, CEC can determine how much calcium is needed for a particular plant. Another way to assess the excessiveness of calcium is through the pH level of the soil, which is directly proportional to each other. 

Soil with higher CEC tends to have more organic matter and clay in soil due to water and nutrients it holds. Whereas, low CEC soil has more sandy texture. Once the CEC level is determined, soil can be altered by adding lime to make it less acidic, or sulphur to it makes it more acidic.

The right level of CEC and balanced PH value will enhance the presence of calcium in your garden plants. 

how to add calcium to soil
calcium deficiency in plants

Signs of Calcium Deficiency

Even though soil test is the best way to determine the quality of soil, a few telltales can also high lighten signs of calcium deficiency in plants. A few signs of apparent calcium deficiency are 

  • Curling of young leaves and shoots
  • Stunted or weak growth
  • Spotting or scorching on young leaves
  • Stunted or dead root tips
  • Constrained bud growth
  • Chlorosis
  • Leaf tips burnt
  • Fruit damage, e.g. bitter pits in apples or end rot of tomatoes

How to Know When Your Plants Need Calcium? 

Calcium deficiency is easily notable in new plants, but old plants may show symptoms gradually with time. A few of the following things to notice are 

  • Distorted leaves 
  • Yellow patches 
  • Stunted growth 
  • Premature bud and blossom dropping 
  • Weaker stems and roots 
  • The plant may give off the appearance of a dead plant
  • Blossom end rot is a significant sign of deficiency 

End rot usually occurs in tomatoes but can also affect other plants. It starts as a watery spot on one end and can extend to the entire fruit. The spoiled area can spread and darken with time, and become firm or hard to touch.

Blossom End can also occur in plants with enough calcium; hence it can’t be undertaken as a vital sign of calcium deficiency. But can underline the lack of other significant minerals such as magnesium, ammonium and, potassium. 

Water quantity in plants can also affect the nutrient level in plants. Hence soil should be hand-tested often to determine the texture it gives away to maintain healthy plants. 

Consistency and routine checkups are the keys to monitor your plants’ growth to have healthy plants. Additionally, factors like weather conditions, insects, growing conditions, and plant nature may also hinder plant growth. Each plant may underperform or prosper depending on its nature. 

How to Add Calcium to Gardening Soil?

There are many calcium sources present out there. When and how much to apply and which source is best for you, depends heavily on the pH level of your garden soil, the crops you are growing and also the timing.

Although there are several ways to add calcium in your gardening soil. Few of the most effective sources of calcium for all kinds of soil are: 

  1. Soil Additives

As discussed earlier, the first step of adding calcium to your soil is through determining the pH level of your gardening soil. This is possible via a professional soil test. The test results will allow you to decide which additive your soil needs.

One of the best and most common ways to enhance the calcium content of your soil is to utilize a soil additive. The two most frequently used soil additives to improve the level of calcium are gypsum and lime. But before you select one, make sure you test the pH level of your soil and then determine which one would work best for you.

For example, if your need to increase the pH level of your gardening soil, use lime. Adding it to your garden soil can give it the biggest calcium boost but can also make it less acidic. On the other hand, if you need to stabilize the pH level of the soil, then go for gypsum. Gypsum is a fact acting calcium supplement that neither increases nor decreases the pH level of the soil.

You can purchase lime and gypsum from any garden or home improvement store. Moreover, If you only require a little bit of soil additive, you can begin by spreading the compound content around your plants with your hands.

But make sure you wash your hands properly before adding any additive to the gardening soil. In case you have a larger area to cover, you can rent or buy a soil spreader to help you get the job done effectively.

Gypsum: The amount of additive to use depends entirely on the individual needs of your garden soil. When you decide to use gypsum, pour the pack of gypsum into the gardening soil spreader and spread it cautiously over the soil surface of your garden. After this, you can water the garden soil to make it easier for the soil to absorb it.

Lime: If you decide to go with lime, you might have to use a tiller to mix it into the soil surface evenly.

No matter which additive you decide to use, the key to success is to pay attention to the progress of your plants as you may need to insert additional lime or gypsum once a year. But if you have larger crops, you might be required to increase the amount accordingly.

  • Egg Shells

Eggshells contain an ample amount of calcium to be favourable for several kinds of plants. Read on to learn how you can use eggshells to enhance the calcium content in your gardening soil. 

calcium to soil
calcium in plants via eggshells
  1. Instead of discarding eggshells that you use in your meals, save them in an empty jar. Make sure they stay as dry as possible. Keeping them in a storage container or coffee tin should also work well.
  2. Let them sit there for a couple of days before putting them in your gardening soil.
  3. Once the eggshells have dried out completely, put them in a food processor or blender. If the eggshells are adequately dried, they should grind up very easily and result in a fine powder.
  4. The egg power should roughly have a consistency identical to that of coffee grounds or flour. Remember that the finer the eggshell powder is, the better and easier it will be for the soil to absorb the calcium.
  5. You can use either a tilling machine or your hands to mix the eggshell powder into your gardening soil.
  6. This process must be completed at least a few weeks before you plan to begin the cultivation to ensure that the planting soil is in optimal growing condition. 
  7. In case you have already begun your cultivation, carefully lay the eggshell powder around the plants. 
  8. If you do not own a tiller, you can mix a little amount of water to the eggshell powder.
  9. Take an empty bottle and add a few tablespoons of eggshell powder in it for every gallon of water that you are going to use. Shake the bottle to mix the ingredients thoroughly and pour the liquid on to your plants once it’s ready. 

Monitor the growth of your plants and feel free to insert more eggshell powder whenever needed. If you notice that the plants have a hard time growing as well as you expected, you can add more eggshell powder to the soil every week depending on the progress of your crops.

It can take approximately a good 6 to 12 months for specific plants to rivet the calcium contained in eggshells fully. Lastly, if your plants are growing well, then you do not have to add any more eggshell powder. Eggshells are a great source of calcium for gardening soil.

  • Foliar Spray

Foliar application is the easiest and quickest solution for acute calcium deficiency because plants absorb nutrients more efficiently via their leaves as opposed to roots. It’s specifically suggested and most practical for transplants and seedlings.

Many gardeners often use slow-release calcium for their plants. This allows the soil to absorb calcium only when it is needed the most. Foliar sprays can be quickly and inexpensively made at home from seaweed or chamomile.

Chamomile Calcium Fertilizer

Chamomile calcium fertilizer can be made at home by adding a quarter cup of chamomile blossoms to a few cups of boiling water. If you do not have chamomile blossoms, do not worry. You can also use chamomile tea as a substitute for the blossoms.

Whichever you choose, allow the mixture to cool down, and then transfer it into an empty plastic spray bottle to dispense it on your plants quickly. Chamomile calcium fertilizer can last for up to a week. 

Seaweed Calcium Fertilizer

Seaweed calcium fertilizer can be created by placing chopped seaweed in an empty bucket and add few gallons of water in it. Cover the bucket with a lid and let the mixture stay there for at least two weeks. To use it as a spray, dilute this mixture with around a gallon of water for every two-third cups of the mix used.

  • Clam Shell/Ground Oyster Flour

While it’s a great source of calcium, clamshells have very low solubility and therefore require many years to be effective. In addition to this, they will also marginally increase the pH level of your gardening soil over time.

To make clamshell powder simple dry out the shells and blend them in a food processor to make a fine powder.

It can be added with a little amount of water and then evenly spread onto the gardening soil.

  • Wood Ashes

Wood ashes are another excellent source of calcium for gardening soil especially hardwood ashes. They are an excellent source of adding a fair amount of calcium to your gardening soil but keep in mind that they also increase its pH level. If you need to increase the pH level of your soil, hardwood ashes are half as effective as lime.

Make sure to use hardwood ashes and not softwood ashes as they are not recommended.

  • Epsom Salt

Epsom salts can be used every couple of weeks or so to fertilize house plants. Epsom salts act as a catalyst in plant growth. It can be utilized in below mentioned ways:

how calcium benefits plants
epsom salt for adding calcium to the soil
  • Shrubs: a tablespoon of Salts should be sufficient for every 10 feet 
  • House plants can be sprayed every two weeks 
  • Gardening soil can be fertilized with one tablespoon of Epsom salt in a gallon of water once a month. 
  • The weekly spray can prevent insect infestation and other damages
  • A regular spray can help blooming plants such as roses, tomatoes, etc. 
  • Sprinkle salt over the ground to let the soil absorb better if done manually

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Parting Note

There are multiple ways to add and maintain calcium to plants, in addition to the factors discussed above. Each plant has its benefits and shortcoming according to its content and types. Any product you may choose to add to your soil, make sure it’s not hampering the growth of your plant as each plant may react differently. Pay attention to ingredients and apprehend how much of it can be given. Excess fertilizer can cause high salt concentration and inefficient root systems. 

To learn more tips and tricks and ways to look after your plants, do check the blog section on our website.