In the Garden: First step is taking care of soil

How would you like to have a more productive garden with less work and expense? Have I gotten your attention?

Ever since reading “Teaming with Microbes” (Timber Press, 220 pp., $24.95) by Jeff Lowenfels and Wayne Lewis, I’ve been all fired up to change how I work with my soil and accomplish the above goals.

We gardeners have been trained to rototill or turn over our soil every year and to add fertilizers to make our plants grow. Some folks also use chemicals to control weeds or plant diseases. As Lowenfels and Lewis point out, what happens in the soil under normal conditions makes all of this unnecessary.

“Most gardeners think of plants as only taking up nutrients through root systems and feeding the leaves,” they write. “Few realize that a great deal of the energy that results from photosynthesis in the leaves is actually used by plants to produce chemicals they secrete through their roots.”

Now bear with me while I explain why this is so important, preferably without making your eyes glaze over.

The root’s secretions contain carbohydrates and proteins that attract and feed good bacteria and fungi. These guys are very important because they protect plant roots from disease and deliver nutrients to the roots. They in turn are eaten by microbes (nematodes and protozoa), whose resulting excretions are also taken up as nutrients by plants.

But it doesn’t stop there. The microbes are eaten by arthropods – things like spiders and other predatory insects that also eat damaging insects on and around the plants. Then there are the beneficial aspects of earthworms and their subterranean neighbors.

“Worms, together with insect larvae and burrowing animals, move through the soil in search of food and protection, creating pathways that allow air and water to enter and leave the soil,” the authors write.

As you can see, a whole lot is going on in the soil, yet most of us are unaware of the vital activities taking place.

Let’s look at how this knowledge will reduce our gardening workloads and make our plants grow better:

The common practice of rototilling or turning over the soil damages its structure by eliminating the air pockets created by worms and other subterranean critters. Yet the movement of air and water through the soil is essential to healthy plant life. Let’s avoid this practice and let earthworms and their friends aerate the soil for us.

Another important objective is to resist using chemicals, which include fertilizers, herbicides and insecticides. As the authors explain, these products completely alter the “soil food web,” a term they use to refer to the diverse life in and on the soil. As a result, bacteria and fungi won’t take up residence in a plant’s root zone, which affects the rest of the microorganisms that depend on them. Simply put, chemicals throw off the balance in the soil. Wouldn’t it be nice to eliminate the expense of purchasing them?

The best way to foster a healthy soil food web is to supply microorganisms with nutrients to help them become established. This is particularly important if you have routinely used chemicals in your garden. While microorganisms are tiny, feeding them is pretty straightforward.

Build a compost pile using kitchen and garden waste (leaves, small branches, brush, untreated grass clippings and so on), and place an inch of finished compost onto the surface of your garden beds every so often. The authors also recommend using homemade compost tea.

So, are you with me? Let’s take care of our soils and prepare for the best garden ever.

Susan Mulvihill is co-author, with Pat Munts, of “Northwest Gardener’s Handbook.” Contact her at Susan@susansinthegarden.com and follow her on Facebook at facebook.com/susansinthegarden.