Calcium deficiencies often result in stunted growth or abnormal development of young leaves. The leaves may curl or die, particularly on the tips. Eventually, the terminal buds and root tips will also die.
The symptoms show up first on new growth and rapidly growing tissues in your hydroponics. This happens because calcium accumulates in older leaves, leaving the younger growth to become calcium starved.
Keep in mind that a calcium deficiency has such a wide range of symptoms that it can look like other nutrient deficiencies or diseases. In other words, don’t be too quick to make your diagnosis. Consider all possibilities.
Calcium Requirements in Plants
Calcium serves a number of functions. Probably it’s most important contribution is in the formation of cell walls. Calcium acts like glue to bind cell walls together thus adding stability to the cell membrane.
If there isn’t enough calcium available when cell tissues are forming, these tissues will be less stable and have a tendency to break down. Unfortunately, as noted above, the problem can masquerade as a wide variety of diseases or other nutrient deficiencies so the real problem is hard to spot.
Once a cell is formed, the calcium used to bind the cell walls is no longer available for new growth. That’s why new growth will experience a calcium deficiency while mature leaves appear to remain healthy. So now you can understand why it’s so important to always provide a constant supply of calcium for new growth.
Calcium can also act as a buffer to help protect the root system when excessive amounts of other elements are in your solution. Calcium even helps activate enzymes that regulate the flow of water through plant cells.
Circulation of Calcium in Plants
Plants have two basic types of tissues that transport minerals and sugars throughout the plant. They are called xylem and phloem vessels and function in much the same way as your veins and arteries.
The xylem vessels carry water and dissolved nutrients from the roots, through the stems to the leaves and fruit. The water then escapes into the atmosphere through transpiration which is similar to our exhaling air. This process of transpiration occurs through small pores called stoma. The process creates a suction which draws water and nutrients up through the plant.
Maintaining a well balanced nutrient solution
Even if you start off with well-balanced nutrient solutions, it can become unbalanced. That’s because your plants may use more of one mineral than another. So you end up with an excess of one mineral and not enough of another. That is why many growers completely change their reservoir nutrient solution once a week.
Another important factor to consider is the strength of your nutrient solution. If it is too strong, this can prevent the roots from taking up calcium. Also, avoid buying cheap nutrients. Some manufacturers cut costs by using calcium and other minerals in forms that are difficult for plants to use.
Maintaining a well-balanced nutrient solution requires regular monitoring with EC and pH monitors. However, there is now on the market a hydroponic nutrient system that automatically balances your solution and eliminates the need for meters and charts. It is relatively new, so ask your hydroponic dealer about it.