Get to Know Your Garden Soil

 The quality of your soil has a profound effect on everything you grow in your vegetable garden. Two key elements affecting our soils are the clay content and soil pH.  Here’s a quick test for you to determine the makeup of your soil. You need a clean jar with a lid, some dish soap and water. Put 4-5 ounces of soil in the bottom of the jar. Add enough water to fill the jar 2/3 full.  Add a drop or two of dishwasher soap. Put the lid on and shake well. Let sit undisturbed for 24 hours. 

You’ll see that the soil has settled into layers. The first layer will be sand. The second layer will be silt, followed by clay, suspended clay, then a small amount of organic material, floating at the top. This is evident in the jar on the left. Typically, you’re going to see a small amount of sand and silt, a large percentage of clay and a small amount of organic material. As you add more organic material, your test results will look more like the jar in the middle. The jar on the right illustrates a well-amended garden soil: dark and rich, with more organic material suspended in with the clay. 

Along with soil texture, the pH of your soil one of the most important factors influencing your gardening success. Soil pH affects the availability of nutrients to plants, as well as the microbial activity in your soil.  No matter the quality of the fertilizer or supplements you apply, plants can’t use them if the pH is too high.  Soil pH is a measure of the acidity or alkalinity of a soil. Think of it as how "sour" or "sweet " your soil is. On the pH scale, 7.0 is neutral, above 7 is alkaline, below 7 is acidic. Bleach for example is very alkaline. Lemon juice is very acidic. Most plants prefer a pH of between 6.5 and 7. Our soils are typically greater than 7.  

Home test kits are a quick and relatively easy way to get a reading on pH and soil nutrients.  For a more complete understanding of your soil, we recommend you get a soil test analysis from the laboratory at Colorado State University. You can pick up a mailer and test instructions in the Hardgoods section of the store. The mailer is free, but you do pay a fee to CSU for the test.  In return, you will receive a comprehensive analysis of your soil. Whether you test your own soil or use the lab at CSU, bring us the results. We'll recommend the right amendments to make your garden soil healthier and more productive. As a general rule, to improve your garden soil and lower the pH, you need to add more organic material in the form of peat moss, coconut coir, sheep manure and organic compost. We recommend you add two to three inches of organic material to your garden in the spring and again in the fall.