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Calcium (Ca) Nutrient Deficiencies

Calcium is oftentimes an underestimated nutrient that is very important to plant growth. Calcium plays a huge part in optimal plant health and nutrition.

Calcium (Ca) Nutrient Deficiencies

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The nutrient calcium is oftentimes an underestimated nutrient that is very important to plant growth. We usually focus our efforts on supplementing and feeding our plants the primary three, nitrogen, phosphorus and potassium, but calcium plays a huge part in optimal plant health and growth.

Why Is Calcium Important?

Calcium is responsible for the structure of our plant’s cell walls. It is a component that is essential for the development of new plant tissue. It preserves membrane permeability allowing the proper flow of nitrogen and sugars throughout the plant. It also stimulates enzymes that build strong root structures. Calcium is an immobile nutrient meaning that the plant cannot transport calcium from one area to another inside the plant.




Identifying Calcium Deficiency In Plants

Signs of a calcium deficiency can be detected on the upper, younger leaves, and on the overall plant growth. Symptoms result in slight yellowing, and the tips of leaves will turn brown to black and die off. Calcium deficiency causes the new leaves at the top of the plant to look misshapen. Crinkled, distorted leaves with curled tips are a definite sign of a deficiency. Growth of the plant as a whole will be stunted, as a deficiency will fail to promote the growth of lateral shoots.


  • Youngest leaves will be stunted and deficient
  • Very little lateral shoots
  • Leaves will distort and curl at the tips
  • Young leaves will often turn a very dark green color


Examples Of Calcium Deficiency


How To Correct Calcium Deficiency

As with nearly all other required plant nutrient needs, one of the first things to take a look at is pH balance, in both soil and hydroponic growing systems. A pH imbalance will block nutrient uptake through the plant’s roots. It is important to regularly check the pH, and to be sure to keep the pH within the appropriate range for soil or hydroponics. The optimal pH range for most plants is roughly between 5.5 and 6.5. In this range, the nutrients present in the soil or water are soluble, and are easily taken up through the plant’s root system. When the pH level is outside of this range, even when the proper nutrients like calcium are present, they are not able to be absorbed by the plant.

If you discover that your calcium deficiency is a result of a pH imbalance, it is best to flush your entire growing medium with fresh water and then add the desired supplement, if still needed, in order to correct the deficiency. This process should bring your pH level in balance with where it needs to be. In soil use 3 gallons of pure water for every gallon of grow media. In hydroponic gardens, drain off part of your nutrient solution and replace with pure water in order to balance your pH.

After assurance that pH levels are where they need to be for proper nutrient uptake, you may discover that your plants do indeed need an extra boost. Oftentimes, a calcium deficiency is in relation to other deficiencies such as magnesium and iron. A simple and reliable supplement that gives great results is a supplement solution that provides calcium, magnesium and iron in one shot such as a cal-mag amendment.



Combined calcium and magnesium supplements can also be used as a foliar feed, giving plants a healthy dose of nutrients across their leaf surface. Remember to spray the undersides of the leaves as well. Continue applying nutrients until the deficiency symptoms are no longer present.

Another solution is to apply dolomite limestone to the growing medium. Dolomite limestone is made up of calcium and magnesium, and provides great benefits to plants.

An organic solution is to combine 1/2 teaspoon of hydrated lime per gallon of water to create a calcium rich solution for watering or as a foliar spray.

A calcium deficiency can also be caused by an excess presents of aluminum.



Now that you know the benefits of monitoring the calcium content in your soil and hydroponic growing systems, and what to do when you spot a deficiency, you can be sure to have the necessary tools on hand to keep your plants at their best.


Want to learn more about nutrient deficiencies?

Read our entire nutrient deficiency series as well as learning about micro vs macronutrients.

Questions? Call 888-815-9763 or email [email protected].