At high elevations, acidic fog and clouds might strip nutrients from trees’ foliage, leaving them with brown or dead leaves and needles. The trees are then less able to absorb sunlight, which makes them weak and less able to withstand freezing temperatures.

But the most serious effect of calcium deficiency lies in the roots. Calcium is involved in root extension, and it is necessary for the secretion of protective mucilage around the root caps. Lack of calcium also increases the plant’s susceptibility to root diseases such as Pythium. Without enough calcium, roots often become stunted and discoloured, and they begin to leak the solutes that plants need to grow. This results in a thin, spindly root system that often becomes a slimy brown or black, especially at the root tips. If plants lack actively growing roots, any of the other nutrient deficiencies can appear, often at random

Calcium Deficiency Prevention

The first step to prevent calcium deficiency is to use a water-soluble calcium source, such as calcium nitrate. Some of the other calcium sources used in organic gardening are poorly soluble, and are only slowly released over time. Calcium quickly locks up with phosphates and sulfates, forming insoluble precipitants. So make sure that water-soluble calcium is properly diluted, especially in hydroponics.