What's the Function of Calcium (Ca) in Plants?

Amir Tajer

Posted on December 27 2017

Most people don't realize just how important Calcium is to their plants. However, for plants to grow and remain healthy, there are specific nutrients they need — and Calcium is one of the more important ones. This is why it's important to use a good Calcium fertilizer to maintain the necessary Calcium levels for your plants.

The Function of Calcium in Plants

The nutrients plants need are categorized into three different categories — main nutrients, micro nutrients and trace elements. Nitrogen, Phosphorus, and Potassium are considered primary nutrients. Calcium — along with Iron, Zinc, Manganese, Magnesium, Sulfur, etc — is a micro nutrient and some elements such as Molybdenum, Nickel, Selenium, etc are considered trace elements. Even though the main nutrients are very important for most plants, Calcium is even more important for some plants, such as tomatoes.

In the form of Calcium Pectate, Calcium holds the cell walls of plants together. It also activates specific plant enzymes, which send signals to the plant cells that coordinate certain growth activities. Unfortunately, Calcium is not a nutrient that's mobile in plants, so to prevent a Calcium deficiency, it's important to use a Calcium supplement such as Calcium Nitrate or Cal-Mag fertilizer regularly. However, if you are growing organically, Dolomite and/or Bone Meal are great Calcium supplements.

Why Plants Need Calcium

If your plants don't get the right amount of Calcium, new plant tissues — such as the tips of the roots, shoot tips, and young leaves — can't properly form. Also, the more mature plant tissues will begin to wither faster than they would if your plants had enough Calcium.

Symptoms of Calcium Deficiency in Plants

If your plants have a Calcium deficiency, chances are, you'll first start to notice it as the plants begin producing new leaves or buds. Because the plants don’t have enough Calcium to form proper cell walls, they might appear withered or distorted right away.

Another common symptom of Calcium deficiency is blossom end rot, which is very common in tomatoes, peppers and cucumbers.

Plant growth and the amount of calcium a plant absorbs relies on transpiration — the process in which the plant's roots take nutrients from the soil and transports them to the parts of the plant where new growth is happening. Elements that slow transpiration, such as high humidity or cold weather, can induce Calcium deficiency.

To prevent this from happening, apply a Calcium fertilizer to your plants. If you prefer organic gardening methods, Bone Meal and Dolomite are good substitutes for Calcium Nitrate and Cal-Mag.

The good news is, while Calcium deficiency can be a problem, Calcium toxicity doesn't normally happen. However, it's important to keep in mind too much Calcium can compete with Magnesium and Potassium uptake, causing their deficiencies. So in order to maintain proper levels of all nutrients, make sure your fertilizer solution has Calcium levels less than 200 parts-per-million (ppm).

Fortunately, Calcium deficiency isn't difficult to prevent or correct. Simply use your preferred Calcium fertilizer or a Calcium supplement to achieve the desired Calcium levels when you're gardening.