The Important of Calcium in Citrus Plants and Trees

The Importance of Calcium for the Best Australian Finger Limes, Kumquats, Mandarins, Grapefruit, Oranges and Lemons

The Importance of Calcium for the Best Australian Finger Limes, Kumquats, Mandarins, Grapefruit, Oranges and Lemons

Mani Skaria, Ph.D.


Calcium is the most abundant mineral element in the human body., taking up 2% of the body weight. Our body needs 1000 to 2000 milligram calcium daily. Together with phosphorus, calcium provides structure and strength to bones and teeth.

The figure at the right is the symbol of Calcium, as per the periodic table. Ca = Calcium, 20 is the atomic number (number of protons), and 40.08 is the relative atomic mass (protons + neutrons). It is a hard metal. It is the 5th most abundant element in the earth’s crust.

It is a solid at room temperature. It was first made in Germany in 1669 by Henning Brandt. Elemental phosphorus exists in two major forms, white phosphorus, and red phosphorus. It is highly reactive; therefore, it is not found as a free element on earth.

A basic difference between plants and animals

Animals can move. Plants are sedentary.

When a physician advises on protein deficiency, the patient takes the information and makes corrective measures for themselves and even for their dependents, including pets. People and animals can move around. Whereas, most plant owners are not plant doctors; they have no clue that a plant needs food and water. As a plant doctor, I consider it an unforgivable sin.

Why citrus plants need Calcium

Here are the top reasons why citrus plants require Calcium:

  • It is the key component of cell walls
  • It regulates enzymes
  • It regulates plant hormones
  • Helps nutrient uptake
  • For leaf strength
  • Better fruit yield
  • For better fruit set
  • Helps fight root diseases caused by fungi
  • Helps reduce post-harvest fruit decay
  • Increase resistance to heat and cold stress
  • Increase fruit shelf life

How much Calcium is needed?

Calcium accounts for over 20% of a citrus plant's nutrient content. Citrus leaves contain 3-6% calcium in dry matter.

How do I know my citrus plant is suffering from Calcium deficiency?

  1. Trees lack vigor
  2. Trees defoliate
  • Poor root development and trees stunt
  1. Root system prone to fungal infections
  2. Fruit show albedo
  3. Fruit pitting, creasing, and splitting

Specific positive roles of adequate Calcium

  • Increase yield
  • Increase fruit weight
  1. Increase shelf life
  2. Fight diseases

Growing trees is fun, but if you want to have delicious, seasonal citrus fruit right away, join the Craft Citrus Club!

Get a curated box of fresh-harvested citrus fruit from South Texas sent to your door every month!

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