Minerals make up about 90 percent of garden soil. Unless we dig up an entire garden and import new soil, (and we don't want to do that), mineral soil particles are important for holding onto many plant nutrients. Creating a desirable soil structure enables plant roots to absorb  nutrients. With proper attention to the soil, you can build a viable, nutrient-rich environment for growth.

Geologic forces move slowly to build perfect soil like that found in a tropical forest. It takes tens of thousands of years for rocks to wear down into small particles of sand, silt and clay small enough to be valuable to garden soil. Large rocks cannot hold onto plant nutrients. If you were blessed to inherit grandma's fastidiously maintained garden, you may know she spent a lifetime working to cultivate and maintain a good soil structure. That is what it took her to make it perfect, adding compost, removing large chunks of rocks, weeding, constantly turning the soil and adding amendments three times a year. Dedication to the garden requires dedication to the soil.

Getting down to the rocks and minerals of the soil, the texture can range from sand, silt, clay to peat. Each of these forms may vary in texture, structure, aggregation and water retention ability. Also, to be productive a soil must allow air to reach the roots and also retain water without becoming waterlogged. Taken together, these characteristics are known as a soil's tilth. Great tilth equals a high fertility potential.

The variety of rock structures around the world create thousands of varieties of soil. The ground-down particles of rock form the underlying basis of the soil, sand, silt, clay or, the ideal, loam which contain organic elements from the decomposed remains of plants and animals.

On the farmland of a country like the United States, which has been cultivated for hundreds of years, the soil includes the underlying geological strata plus the products of years of farming. This, too, leaves us with highly variable soils. Clays, sands and loams all give color and texture to the patchwork of fields once typical of the countryside.

Rich, dark soils are particularly good at supporting crops such as vegetables and grasses. The dead organic remains from previous crops retain moisture, feed biological life and ensure good soil structure. Other edible crops prefer lighter, more freely draining soils with higher levels of mineral nutrients. The good news is you can always improve the structure of your soil by amending it with the appropriate materials to achieve the desired structure for the plants.

In our gardens, soils are even more varied than those on farms. Most soils can support a colorful range of healthy plants. Even those from the most remote or exotic parts of the world seem to find an agreeable climate somewhere in our gardens. However, in order to grow a wide range of healthy plants, you need to know what your soil is composed of, and how to improve it.

Milo Lou Shammas
Founder and Formulator