Hello again, Westside Gardeners.

I am often asked, “What can I do about my soil, and why won’t my plants grow?”

Let’s face it: our native soil here is lousy since it has little to no nutrients, including no organic matter.

When asked these questions, my response is, “Let’s do a soil sample and have it analyzed.” When receiving the analysis, it will contain the pH value, electrical conductivity, fertility, ESP (exchangeable sodium percentage) and mechanical analysis.

Unfortunately, when I test the soil here in the Westside, the results are often the same, showing very high levels of salinity and alkalinity.

Here’s the secret to getting plant material and trees to grow and be healthy here in the Westside: it’s simply incorporating as much organic compost and organic fertilizer into the native salty, heavy clay as much as possible.

When mixing the organic material and fertilizer, I also like to add a pilled form of gypsum and calcium, which will help break down the salinity and alleviate the heavy texture of clay particles. Most importantly, add an even, continuous layer of arbor mulch after working the soil and planting.

Adding mulch regularly not only retains moisture in the soil, but as it breaks down, it adds additional organic humus, which makes the soil alive with microbial activity.

Always remember, plants and trees will only be healthy and vigorous if the soil is alive.

Mark Koehler

Mark Koehler of Los Banos is an arborist and master gardener, who has degrees in Landscape Architecture and Landscape Horticulture from UC Berkeley and Northeastern University.