The foundation of any great lawn or garden is its soil. Healthy soil provides plants with three key elements: water, nutrients and air.
The best soil provides adequate drainage and water retention, plus enough aeration for root growth. There are several classifications of soil as defined by the US Department of Agriculture (soil texture triangle). For the purpose of this article, we will separate it out into three categories: clay soil, loamy soil and sandy soil.
USDA Soil Texture Triangle
Clay Soil:
Clay soil is the densest type of soil. Due to its density clay soil takes the longest to soak up water and also takes the longest time to release it. Although clay soil has excellent water retention properties the density of the soil decreases aeration which can negatively effect on root growth. Clay soil can be difficult to work with as it tends to stick together.
Loamy Soil:
Loamy soil has a good combination of sand, silt, clay and organic matter. It is the preferred type of soil to plant in as it has good drainage, good water retention, and good aeration for root development. It is also easy to work with if it’s not too wet.
Sandy Soil:
Sandy soil is extremely easy to work with, even if the moisture level is high. It also has excellent aeration properties. However, it has a very low capacity for retaining water so unless you water frequently sandy soil can take plants to what’s called “the permanent wilting point” or death.
What Kind of Soil Do I Have?
There are two easy tests you can do to see what kind of soil you have. The first is to do a “squeeze test”. To do this, gather a handful of slightly moist (not wet) soil from your yard or garden and try to squeeze it into a ball in the palm of your hand. If the soil clumps together, feels pliable and stays in a ball, you have clay soil. If the ball falls apart shortly after you open your hand, you have sandy soil. If the soil is somewhere in the middle, you have loamy soil.
The other test is the “jar test”. Fill a jar with one part soil to three parts water. Put the cap on and shake the jar vigorously until the soil and water are well-mixed. Let the jar sit undisturbed overnight. In the morning take a look at the jar. If the water is almost clear at the top and the dirt has settled to the bottom, you have sandy soil. If there is a very distinct line of clay along the upper edge of the soil, you have clay soil. If the water looks dark and rich (there may even be pieces of organic material floating in it) you have loamy soil.
Fixing Your Soil:
If you have clay soil, or sandy soil, you can improve its drainage characteristics by mixing in organic compounds such as compost, grass clippings, leaves or straw.
Step 1: Add approximately two inches of organic compound and mix it in to a depth of about six inches. If you’re already supporting some growth you may be able to skip this step.
Step 2: Top off with at least two to four inches of high quality loamy soil.
If it’s at all possible, do not spread topsoil when its moisture content is high. The soil will not only be difficult to work with when it is wet, but will “bake” in whatever shape it is in when the sun hits it. The only soil that will not be difficult to work with when it is wet, or “bake” into a shape, is soil that has a high sand content…and that may be why you’re trying to fix the soil in the first place!
