Calcium deficiency: how do you recognize a calcium shortage in your plant?
A calcium deficiency in plants has far-reaching consequences for cell development and energy supply within the plant. It is therefore very important to signal a calcium shortage in time to prevent greater damage to the plant.
Calcium is one of the most common substances in the world and with 4% of the earth’s crust, calcium is the 5th most abundant substance on earth. Well-known minerals with calcium are calcium carbonate and gypsum.
Calcium ions (Ca2+) play a major role in the functioning of cells. They provide, among other things, the transmission of signals within the cell (signal transduction). Furthermore, calcium in animals ensures the functioning of the muscles and ensures healthy bones.
What is the function of calcium for the plant?
Calcium occurs throughout the plant and is necessary for many processes that take place, including the growth process and the ability of the plant to evaporate. However, it is the most important thing for the growth process of the plant. The element lifts from the substrate through the roots through the plant. Calcium, however, is not mobile within the plant, so in the case of a calcium deficiency, the least evaporating plant parts have the first shortage.
It is important that the plant always has sufficient calcium available from the substrate for absorption via the roots. The main functions of calcium are cell division and indirectly it also plays a role in the energy supply within the cell.
How do you recognize the symptoms of a calcium deficiency in plants?
A calcium deficiency can be recognized by the yellow spots on the leaves, which are sharply marked with a brown edge. These spots are necrotic spots and completely turn brown later, as the calcium deficiency continues. Also, the plant doesn’t grow well anymore.
The symptoms of calcium deficiency always occur quickly: within one to two weeks the first yellow spots are visible on the older leaves. The spots on the leaves usually start as small, light brown dots, which later grow in size. In most cases it is not the lower leaves of the plant, but just above it.
When the shortage continues, the grower gets confused, since the stains can also occur at the edges of the leaf, as is the case with a potassium deficiency.
Nevertheless, the difference between a calcium deficiency and a potassium deficiency is usually clearly noticeable: the spots with a calcium deficiency are sharply marked on the leaf, while the brown spots with a potassium deficiency start from the edge of the leaf and grow inwards.
Another important symptom is that the young growth of the plant has been affected. The young leaves curl down and new stems turn purple or yellow.
How does a calcium deficiency develop?
In the initial phase, small brown-yellow dots with a sharply marked brown edge appear on the leaves. After two weeks, the older leaves also get affected and it is clear that the plant hardly grows anymore. Slowly the older leaves die and the growth and flowering of the plant decreases even further.
Causes of a calcium deficiency
A calcium deficiency can be caused by under-fertilization or by incorrect fertilization, such as occurs with a wrong ratio between several elements, such as magnesium, potassium and / or sodium. Ammonium inhibits the absorption of calcium very strongly, while sodium hardly inhibits the absorption of calcium.
The degree to which the plant can evaporate water can also play a role in a calcium deficiency. When the plant grows in an environment with a much too high humidity, the plant can hardly evaporate its moisture.
An often underexposed factor is the hardness of the tap water that is used for the nutrient water of the plants. Hard water contains dissolved calcium salts and is therefore of great influence on the EC value of the nutrient water, so that it contains too many harmful calcium salts.
What can you do if you have a calcium deficiency?
If your plants have a calcium deficiency, you can choose to add highly calcareous fertilizers such as dolomite, gypsum, calcium nitrate or foam to the substrate. This is especially a good solution when there is a calcium deficiency in the substrate, as this reduces the acidity of the substrate. You can also opt for calcium-rich plant nutrients, like Calmag.
If there is a high EC and pH value due to hard water, you can rinse the substrate with slightly acidified water.