Archive for Thursday, January 19, 2006

Sort out the myths about springtime soil preparation

January 19, 2006


As gardeners contemplate the unseasonably warm temperatures and begin to plan their spring gardening activities, a discussion about soil is sure to arise. With the heartland being a melting pot of people from all around the world, there are many myths and beliefs about how soil should be treated in our area. So, as we anxiously await that first frost-free morning, here are some misconceptions to mull over before you work the soil to "make it better" this year.

Time and time again you will hear this: "To make plants grow, you need to add lime to the soil." Not true. Lime is traditionally used to adjust the soil pH to make the soil less acidic. However, in our area, most soils have a neutral or slightly alkaline soil pH, and therefore they do not require lime. In fact, if lime is applied at too high of a rate, the pH may rise high enough to cause problems and not solve them. To know whether your soil needs to be amended with lime, take a soil sample and use science, not fiction, to tell you how much, if any, needs to be applied.

Those coming from the southern United States know what it is like to garden in sandy soil - a far cry from our heavy clay soil. As a result, many times you will hear this: "To increase drainage, add sand to the soil." Not true. The three main ingredients for creating concrete are limestone, sand and water. As noted above, our soils contain more than enough lime because they come from limestone found deep below the soil surface. Likewise, we receive on average of 36 inches of rainfall each year. So what happens when you add the third key ingredient to the soil? You have soil that is even more poorly drained and more difficult to work - a soil more like concrete. The only true way to increase soil drainage is to continually add organic matter. Organic matter is the glue that binds clay particles together, creating a soil that is light, fluffy and better drained.

Finally, because our soils are heavy and hard to work, many times people will tell you this: "Apply gypsum to loosen the soil and make it easier to dig." Not true. Gypsum will not help loosen heavy clay soils. What gypsum can do is cause a chemical reaction to take place in the soil that releases salt, thereby allowing water to move more freely through the soil. This, however, only happens in soils that are full of salt, called sodic soils. We do not have sodic soils in our area. We have good old-fashioned clay. The only way to break up that clay is to add organic matter. Increased organic matter leads to increased nutrients, better water and oxygen movement, and ease for digging and planting. So save your money and do not purchase gypsum; rather, purchase organic matter and begin building your soil.


Use the comment form below to begin a discussion about this content.

Commenting has been disabled for this item.