Did you know that dirt and soil are not the same thing? Dirt can be found when you clean under your fingernails while soil is what you stand on. Soil is found on Earth’s surface and is a thin land covering. It does not extend very far down into the ground. Soils can be found in a variety of colors including yellow, black, white, red, gray and brown. Different soils also vary in texture, mineral content and structure (along with colors) which are considered “soil properties.” Good soil is essential in the process of growing beautiful, healthy plants and flowers.
Weather plays a part in the formation of soil. Rocks can become smaller when the weather is cold or larger when the weather is hot. When these changes occur often the rock begins to crack and break apart creating smaller pieces. These smaller pieces continue to break into even smaller pieces. The very tiniest of pieces become soil. Limbs of trees, dead leaves and dead bugs are all examples of other things that also help to create soil. They are considered the parent material of soil. Basically there are four components of soil: organic matter, soil water, mineral matter and soil air. Soil is very porous and these pores hold the water and air. Soil is broken into several different horizontal layers or “horizons.” The very top layer is the O horizon which is only about one inch thick. It is comprised of dead things that break down and keep soil healthy. The A horizon is the next layer down. It is the topsoil which is alive with things such as roots, microorganisms (such as fungi and bacteria) and creatures (such as worms). As you proceed further down you next find Horizon B. This is a difficult layer for animals and plants to get through because it is very hard. The final soil layer is the C horizon which consists of less living things things than horizons O, A and B. The parent material of the C horizon comes from soil and rock that was formed from all the layers above it.
One of the best ways to care for and improve your soil quality is to add organic matter. Compost is a decomposed type of organic matter that is reused as a fertilizer. Other good types of organic matter which can be used as a fertilizer include: well-rotted manure, leaves, peat moss, grass clippings, organic mulches and topsoil. Before adding organic matter it is a good idea to kill off vegetation that already exists in the area where you will be planting. You don’t want this vegetation to compete with your new plants. You can kill the vegetation by using a flat spade to remove grass sod plus a few inches of soil. Next you put in its place different organic materials and purchased topsoil. Place two to four inches of the organic matter (such as compost) in the area and work it well into the soil. When you add the organic matter you may also want to mix in any lime, sulfur or fertilizer that you need. You never want to over-fertilize so it is a good idea to have your soil tested first. Your local Extension office can provide you with more information on soil testing. Lime or sulfur are used to adjust soil acidity.
pH & Acidity
Necessary plant nutrients are dissolved in ground water that plants use their roots to absorb. When too much acid is in the soil nutrients dissolve too fast and become depleted when water drains. When there is not enough acid in the soil and it is considered too alkaline, nutrients do not dissolve fast enough. Soil that is said to be “neutral” is neither too alkaline nor too acidic. Neutral soil is the best type to help flowers and plants to truly thrive. Soil pH (potential Hydrogen ions) is an indicator for relative soil alkalinity or acidity. There is a scale for soil pH that ranges from zero to 14. Neutral soil is a seven on the pH scale. Soil that rates less than seven on the pH scale is considered too acidic while soil higher than seven is considered too alkaline. Soil pH measures hydrogen ion concentration in soil water. Hydrogen ions are considered acid cations. Greater hydrogen ion concentration in the soil water means lower pH. The soil acidity is greater when the pH value is lower. Sulfur is useful in lowering the pH and making your soil more acidic. Lime is good for helping to increase the pH and make your soil more alkaline.
Soil provides plants with many important nutrients which they need in order to be healthy and grow. Yet most soils do not provide plants with all of the nutrients they require. Supplementing mineral nutrients in soil with fertilizer helps to make plants thrive. Plant foods contain three necessary nutrients which include: N-nitrogen, P-phosphorous and K-potassium. Each of these nutrients helps meet the nutritional needs of plants. Small amounts of other nutrients are often part of many plant foods as well. You will find that plant foods are labeled by percentages of the ingredients that are in them including N, P and K (always in this order). There are three different types of plants foods which include: granular complete (place it on the surface or mix it into the soil and water after spreading); water-soluble (mix it with water in order to apply it); and slow-release (place it on the surface or mix it into the soil and it continues to release over time).