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5 Simple Ways to Add Calcium to Your Soil

5 Simple Ways to Add Calcium to Your Soil

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Getting your plants to grow is often a delicate alchemical balance whether you are tending a small garden in your window boxes or an extensive backyard farm. Your plants need to get precisely the right amount of sunlight, water, and nutrients for them to thrive.

One of the hidden aspects of growing healthy plants is soil composition. Plants need the right balance of acidity and different nutrients in the soil to grow, but it is often difficult to gauge soil composition with the naked eye.

Most gardeners struggle with calcium-deficient soil, which leads to small, stunted plant growth. However, if your soil is naturally calcium-deficient, it does not mean that your plants are doomed because there are many ways to add calcium to the soil.

There are so many ways to add calcium to the soil that it can be overwhelming to choose a method! Here is a guide to the different ways to add calcium to your soil and how to decide which method is more appropriate for your needs.

Why Do Plants Need Calcium?

Calcium is one of the most important macronutrients naturally found in soil. It is crucial to plant growth and stability.

Plants absorb calcium for many of the vital chemical processes that allow them to grow. For example, calcium plays a vital role in forming new cell walls and growing new shoots and leaves.

Calcium is also vital to creating the kind of soil structure that supports plant growth and nutrient absorption. The mineral makes soil absorb water better and displaces sodium, which is harmful to plant roots.

Because calcium is so important for plant growth, it needs to be present in the soil at all stages of a plant’s life cycle. This means that you need to continuously test your soil and choose methods that add calcium in the long term as well as the short term.

Why Do You Need to Add Calcium at All?

If calcium is a naturally occurring mineral, then why do many gardeners need to add it at all? Often, a garden or plant bed does not have enough calcium for the plants to grow properly.

There are many reasons why soil could be calcium-deficient. This often happens for natural reasons, for example, if an area is going through a drought period. Soil also tends to have less calcium early in the season because winter leaches the nutrients out of it.

Healthy soil can also become calcium-deficient over time as it becomes more acidic. Soil becomes more acidic due to overuse when it absorbs too much decaying organic matter, or gardeners harvest too many crops.

Even if the soil has enough calcium, gardeners sometimes add more anyway because certain plants require more of the mineral than others. Vegetables, fruits, and legumes, in particular, need more calcium to grow their fruits.

Testing the Soil

You can often tell if your soil is calcium-deficient without testing the soil at all, just by looking at your plants. If your plant is growing slowly, its younger leaves look shriveled, and its veins are turning brown, it could have a calcium deficiency.

To be certain about whether or not you need to add calcium, you can always test your soil. At-home calcium tests are expensive, but at-home soil pH tests are relatively cheap.

At-home soil pH tests don’t test directly for calcium levels, but they can tell you how acidic your soil is, which gives you a good idea of the calcium amounts as well. If your soil is alkaline, meaning that it has a pH that is greater than seven, its calcium levels are probably high as well.

You can always get your soil tested specifically for calcium levels by sending it to a professional agricultural laboratory.

Ways to Add Calcium to Soil

Once you figure out that the problem affecting your plants is a calcium deficiency, there are several ways that you can supplement calcium levels in your plant beds. The method you choose will depend on the amount of soil you need to treat, how long you have, and whether you want to use natural methods or artificial supplements.

1 – Eggshells

Believe it or not, you can change the composition of your soil using pantry ingredients such as eggshells. This method works best if you have a smaller garden patch or plant row, as large fields will require lots of eggshells.

Before you can spread eggshells among your plants, you need to prepare them. First, they need to dry out for several days in a storage container.

Once your shells are dry, then you can grind them into a fine powder using a blender. Once you have your eggshell powder, mix it into your soil using a tiller, with your hands, or by combining the powder with water to create a sprayable mixture.

It is best to use the eggshell method before you plant or when you are looking to create a long-lasting, stable calcium balance in your soil. It can sometimes take months for the protein in eggshells to fully break down and be absorbed by plants, so if your garden needs an urgent calcium infusion, this may not be the method for you.

2 – Epsom Salts

The key to saving your garden might be waiting in your medicine cabinet. Epsom salts, or magnesium sulfate, are not just good for running a bath; they can also improve your soil’s calcium levels.

Besides improving the calcium levels of your soil, Epsom salts have other benefits. They prevent plant rot, help plants grow better, and improve the absorption of crucial nutrients such as nitrogen and phosphorus.

To apply Epsom salts to your plant beds, you need to turn it into a mixture first. Add about a tablespoon of the salts to a gallon of water, then spray it on your plants.

If you are using Epsom salts to help your plants, you should reapply them regularly every few weeks.

3 – Calcium Spray

Calcium spray gives plants a mineral boost when they are looking a little droopy. While professional farmers buy spray for their plants, you can make a quick-acting solution at home using basic ingredients.

One option uses chamomile. Make a regular chamomile tea or steep chamomile blossoms in boiling water, then add to a spray bottle once it’s cooled.

Seaweed also has high calcium levels that can be beneficial to your plants. Add seaweed to a bucket with several gallons of water, then let steep for a few weeks before adding to your soil or putting it in a spray bottle.

While these solutions are natural and made with ingredients that you can find at home easily, they are also less long-lasting than store-bought soil additives. You probably need to reapply these sprays every week.

4 – Lime

If you have a large field where you grow plants or your soil is in dire need of calcium, you can add soil additives or calcium fertilizers. The most common varieties are lime and gypsum.

The type of fertilizer that you choose will also depend on your soil’s overall chemical composition. Regular lime can boost your soil’s pH, which is helpful if you are dealing with acidic soil. Dolomite lime, or calcium carbonate, increases your soil’s calcium levels, magnesium levels, and pH levels.

If your pH levels are fine, then you can add gypsum, or calcium sulfate. Gypsum has the additional benefit of acting quickly, so this is a good choice if you need to raise your soil’s calcium levels immediately.

You can usually buy bags of gypsum or lime at your local hardware or garden supply store. You can apply it with your hands (just be sure to wear gloves) or with a soil spreader if you have a larger surface that you need to cover.

5 – Wood Ashes

Wood ashes are another type of soil additive that can raise the calcium levels of your soil. However, be sure to pick out hardwood ashes, as softwood ashes can be detrimental to your garden.

As with lime, hardwood ashes also raise your soil’s pH, making it less acidic. They are about half as strong as lime, so choose this option if your soil is only slightly acidic.

Other common types of soil additives include bone meal and colloidal phosphate. You can find most of these at your local garden supply store.

Raising Your Soil’s Calcium Levels

A healthy calcium level is crucial to growing a healthy garden. Plants need this mineral to absorb nutrients and to grow, particularly if they are growing fruits or vegetables.

You can make calcium solutions at home using eggshells, Epsom salts, or even chamomile. If your soil is very calcium-deficient and has other nutrient issues, then you can turn to store-bought additives such as lime, gypsum, or wood ashes.

Before adding any solution to your soil, make sure that what you are adding will help your soil and not cause more problems. Do a little research about the amount of calcium that your plants need, or even get the soil tested professionally to find out about any other deficiencies.


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