Characteristics of Loam Soil

Several different types of soil are used to grow various species of plants. Each soil has a different consistency, a different look and a different balance of minerals, moisture and oxygen. Loam, for many reasons, is a nutritious and healthy mixture that helps a diverse group of plants and vegetables thrive.


Perhaps one of the most defining characteristics of loam is its fertility. This soil is moist, loose and full of biomaterial such as decaying worms and microbes that can be recycled as food for plant life. Because of this, loam soil is considered the best soil in which to grow vegetables, garden fruits and flowers such as roses. Loam soil gets its nutritious qualities from decaying insects and other animals and plants. When these organisms decay, they release nutrients into the soil that are stored as dry parts of the soil. Worms and other subterranean life mix the soil and create passages where water can work. When it rains, the nutrients in the soil are released and are soaked up by plants' root systems.

Physical Makeup

Loam is a mixture of sand, silt and clay. In fact, several variations of loam exist and can be used to grow different types of plants and vegetables. Standard loam is composed of approximately 40-percent silt, 40-percent sand and 20-percent clay. Other variations include silty clay loam, which is made up of only 10-percent sand, 70-percent silt and 20-percent clay. The pH level of loam ranges, as different ingredients are present in different proportions due to variations in the soil composition, but the standard loam pH is between 5 and 7. This low level of acidity is good for plants and vegetables, as it kills off some forms of bacteria and microbial life that might otherwise attack a plant's root system.

Other Characteristics

Loam soil appears rich and dark brown and is usually moist to the touch. You can pick up loam and roll it into a ball, and it will crumble when touched. This ability helps determine whether clay, silt and sand are present in the correct proportions. When you run water over loam, you will see that loam soil tends to drain very well and yet still retains its characteristic moisture. This ensures that the plants have a healthy base in which to grow without the roots being drowned under collected water.