February is here and plants are in a state of confusion. The unusually warm weather in January has encouraged tender leaves to emerge from some trees and shrubs ahead of schedule. Looking out my office window at the maple trees in the quad area, you could get the impression that spring has arrived. As I was admiring the maples, I thought about the soil and its importance to plant life. Mr. Jim Volgas, a 15 year Extension Master Gardener with the Memphis Area Master Gardener Association, recently taught a session on “Soil Basics”, which reminded me how important soils are.
Earth is covered by a thin layer of soil that is composed of organic matter, minerals and living organisms. As gardeners, we depend on the soil to grow our food or to beautify our landscape. Even the homes we live in are supported by the soil.
The primary component of soils is minerals. Minerals are developed from weathered rock called parent material. These minerals are usually deposited by ice, water, wind, and gravity. Soil properties are usually determined by the type of rock the parent material initially came from.
Organic matter is another component of soils. Simply stated, organic matter is decomposed plant and animal parts. Microscopic soil organisms help break down minerals and organic residues that give us organic matter. Organic matter is a constituent our plants need to thrive.
The distribution of particle sizes in the soil is called soil texture. Sand, silt and clay refer to particle sizes. Sand would be the largest and clay the smallest. Rubbing the soil between your fingers can help indicate soil texture. Clay soil feels sticky and slick, silt soil feels silky and sandy soil feels gritty. Soil texture can also indicate stability, strength and drainage capacity.
I frequently hear gardeners talk about the amount of clay in the soil. Believe it or not, the soils here in Shelby County are not that bad. The clay holds nutrients and water which are admirable qualities needed for plant growth. It wouldn’t hurt to add organic matter to that soil from time to time. As Mr. Volgas says, “it’s all about pore space.”
Until next time, let’s show the soil some love!