Surf City Times: June 8, 2002
ROCK STEADY by Dr. Curly

Hello fellow Earthlings, and welcome to the rock pile. For centuries native peoples familiar with agriculture have known that certain rocks, when crushed into a fine powder, made their crops grow better. This is also somewhat known to us, yet we don't often make the connection between crushed Limestone, Gypsum, Dolomite or Sulfur as rock dusts or powders. Sometimes I'm not really sure if gardeners think of these things at all.

Plants, much like animals, and humans require a number of minerals in order to properly develop and grow strong and healthy. In alkaline soils we commonly find people using Gypsum (calcium sulfate) to break up their clay. Often they don't even realize that the calcium in their gypsum is what is loosening the compacted, tight earth and the sulfur is what keeps the pH of their soil from rising too much higher. In the east and in parts of the country where summer rains and acidic soils are popular we find gardeners using crushed limestone (Lime) to raise their soil pH. This is not all that the lime does either. It is important to note that the addition of calcium as gypsum, lime or any other form has several other properties that affect plant vigor.

Calcium pectase is formed inside plant tissues. This makes cell walls in plants sturdier and less collapsible. This has a direct effect of how drought and frost tolerant our plants can be. The more calcium available, the stronger cellular tissue is, which creates a reluctance by the plant to give up moisture through that tissue. This makes plants "hold their water," better, thus a more drought tolerant plant is created. So now using calcium-rich minerals makes even more sense as part of our regular feedings in order to save on expensive, dwindling water resources. Fossil marine algae (kelzyme), Agrowinn-Minnerals, Gypsum, and the regular application of composts or worm castings to our gardens will increase calcium levels and improve soil and plant quality.

Iron is another commonly misunderstood essential mineral for proper plant growth here in the west. Our normally alkaline soils prevent the iron in our soils from being readily available to our plants. We often see evidence of this when the leaves on our citrus gardenias azaleas, and other plants turn light yellow and the veins of the leaves remain green. This condition is known as iron chlorosis and is very common here. Yet every time I've witnessed a person carrying a chlorotic leaf into a garden center or nursery, some sales hack shoves Ironite at them instead of really showing them how to permanently work on the soil. Iron-rich supplements for soils and working on lowering our soil's pH is the only way to reclaim iron from the soil for our plants. Ironite is a temporary, expensive remedy that creates more frustration with the problem. Using composts to assist in balancing soil pH, using rock dusts rich in iron such as Agrowinn-Minerals, or using natural/organic fertilizers like blood meal will slowly recover any soil where iron chlorosis is a common occurrence.

In closing, I'd like to let you know that you can get good composts from lots of nurseries and garden centers very inexpensively. Blood meal is also available at most full-service garden centers.

Agrowinn-Minerals is available at Grangetto's Farm and Garden Supply in Encinitas and at Cedros Gardens in Solana Beach (ask for Mia of Larry) and Kelzyme is available at Anderson's La Costa Nursery in Encinitas (ask for Celeste or Mike).