Understanding Soil

Today we’ll be discussing soil as it relates to growing and maintaining a healthy lawn.

When it comes to lawn care and gardening in general, the success of grass or any plant begins with the soil. Soil acts as the food source for your lawn, holding and delivering nutrients, minerals, water, air, and organic matter to your grass.

Much in the same way we pay attention as to what we eat and put in our bodies, the same care and consideration should be made when it comes to maintaining a healthy soil. The more chemicals we ingest in our food, the less healthy we tend to be. The same applies to synthetic, chemical lawn care vs. organic lawn care.

The Anatomy of Soil

So what is soil exactly? In short, it is a living organism beneath your grass and other plants.

Soil is made up of minerals, organic matter, sand, silt, clay, and living organisms (earthworms, nematodes, bacteria, etc.). Through many interactions and changes in bedrock beneath the soil, heat, water, and air interactions, in combination with living organisms moving material, we have what we think of as “soil” (Tukey 34). 

The processes by which soil is created is beyond the scope of this blog, but just know that it takes many interactions and thousands of years to produce the soil we grow plants in. 

So what is the important take-away? In essence, you want to be familiar with what type of soil you have so you can better understand what your options are to make it more fertile for grass to grow. 

Types of Soil and What it Means for You

Soil can first be categorized into three types of textures: silt, sand or clay. There are further sub-textures and mixes as well but if you’ve ever gardened or played in the dirt as a kid in Missouri you know that we tend to have clay-type soil.

Clay soil is distinctive in that it feels heavy in your hands and sticks together when wet. It is rare that you can grow plants or vegetables easily without adding compost or soil amendments when planting. Luckily, grass can grow quite well in it if you do some basic maintenance that we’ll get to in a minute. 

Soil can further be categorized on its structure, not to be confused with texture. Whereas texture is the sizes and proportion of individual particles that make up the soil, structure refers to how these individual particles stick together or clump (Tukey 35). 

In the clay-type soil of Missouri, the structure tends to be dense and compact. This is important to keep in mind when it comes to lawn use. Too much foot traffic, pets, outdoor sports, etc. can lead to further compaction of an already dense soil. 

A good way to alleviate the stress from these types of activities is to have a year-end soil aeration performed. You can have a lawn service do this (like GreenTech Lawn Care) or you can find what’s known as a core aerator at your local hardware store. The objective is to make sure the soil gets de-compacted and allows for air and organic matter to enter the soil.

Another stressor for your soil can be the over-application of fertilizers, synthetic or organic. For lawns that are unhealthy or dead, we recommend a soil test from the MU Extension office to determine what nutrients need to go into the soil and at what quantities. 

For lawns that are already healthy, we recommend our organic fertilization program with properly applied amounts of chemical-free fertilizer.

What if My Soil Chemistry is Right, Now What?

Beyond the science-y details of soil, it is crucial to have proper soil depth and drainage for a lawn to be healthy. “Depth simply refers to the amount of good soil available for the grass to develop roots. Drainage is soil’s ability to keep water moving (Tukey 37).”

Grass needs at least six inches of quality topsoil to grow, preferably up to twelve inches. Drainage issues can occur if you have low spots in a really flat lawn and can be fixed with various techniques such as an underground basin or trench/storm drains.

Depth and drainage issues tend to occur if your home is new construction or if you’ve have excessive erosion occur.

If you have a new home built, make sure the contractor hires someone to properly install your lawn! If you have erosion due to the elements, you need to have a professional landscaper evaluate your yard. We recommend local company Sustainable by Nature for depth and drainage issues. 

In Summary

When it comes to the soil and your lawn, it’s best to keep in mind that soil is a living organism that is similar to our bodies in that what you feed it will determine how healthy it is. 

Various factors such as foot traffic, pets, erosion, how you mow your lawn, and chemical vs. organic fertilizers all play a part in how your soil supports healthy lawn growth.  

Sources: The Organic Lawn Care Manual, Paul Tukey