How to improve any kind of soil

Soil is so foundational to growing any plant that it is often the subject of many conversations I have with gardeners here in Saline and Ottawa counties.  Good soil health plays perhaps the largest role in being able to grow a plant to its full potential with the least amount of problems.

The only catch is that most soils we as gardeners are dealing with tend to be in less-than-ideal health.  Soils in our area may have very high clay content, high pH, low levels of organic matter, or various other issues.

The question often is, how can I improve my soil?  The good news is that there is a fairly simple answer that will help anyone with any type of soil.

Add organic matter

Organic matter is often one of the first answers I give in response to the above question.  Without a doubt, organic matter benefits any type of soil.  Organic matter provides some nutrients to plants and it also acts as a sponge in sandy soils to help hold water and nutrients and it provides aeration in heavy clay soil to increase oxygen levels.

There are many forms of organic matter, which means anyone can find something at fairly low cost to use in their specific situation.  Sources of organic matter include things such as:  compost, old leaves, old rotten hay or silage, peat moss, composted/dry manure, green cover crops, or untreated grass clippings.

How it works

Soil is made up of several components including the mineral material, water, air, and organic matter.  Organic matter typically makes up only 5% or less of most soils, but its value in keeping soil healthy is critical.  Organic materials are critical because they are the foundation of the soil food chain. Organic matter feeds and houses microbes in the soil.  The microbes that feed on organic matter then produce compounds that act like a glue in the soil.  This ‘glue’ is what is critical as it gathers and holds soil particles together as aggregates.  Without aggregates (clumps of various sizes), soil would not hold or have space for oxygen and water which are essential to root growth for all plants.

Healthy soil actually has plenty of ‘open’ space for water and air. Organic matter feeds soil microbes that aggregate soil to provide this valuable open space in the soil.

How to use it

Applying organic matter to soil is a fairly easy process.  A typical starting application would be to spread up to 2 inches of the organic material over the soil surface and incorporate it thoroughly to ensure it is evenly distributed in the soil without layers or pockets. 

Fall is a good time to incorporate organic matter since free materials like falling leaves are available and the winter will further break down materials in the soil, but spring is also a good time –just be sure the soil isn’t too wet to work.  If you plan to incorporate organic matter in the spring before planting plan to use a source that is already well broken down.  Finished compost, old composted/dry manures, peat moss, or old rotten leaves will work well in the spring.

There are also other great ways to improve soil organic matter such as by growing and incorporating a cover crop or ‘living mulch’. This publication offers information on garden cover crops.

If you are in doubt about the organic matter level in your soil, a soil test will tell you.  Consider doing a soil test to get the very best idea of how much organic matter may be needed to get to optimal levels.