Right now is an excellent time to apply a layer of mulch over the soil in your garden.
Mulch, which is often just chopped bark or other plant detrius (dead material), is defined as any soil covering. It is a multi-purpose protective layer for your soil.
First, it shields the soil from nutrient and water loss. For example, a mulched garden loses both less topsoil and fewer nutrients in runoff when we have our extreme rains. The same is true when we suffer from the Santa Ana winds. Mulch maximizes the payoff from fertilizer applications because it helps retain the nutrients and also diminishes the effects of runoff and wind erosion.
If everybody were diligent appliers of mulch, there would be less dust to contend with on our cars and trucks, in our houses, and in our lungs. We would spend fewer hours and use less water washing vehicles, and our houses would be easier to keep clean.
Second, mulch shades the soil. This means fewer weeds to worry about. If you are inclined to use herbicides, which can be toxic to people and beneficial animals, plants and micro-organisms, a healthy application of mulch enables you to minimize the use of what are basically poisons, saving you money and making the garden a safer place. If you don’t use herbicides, then that layer of mulch means that you will spend less time weeding.
Third, mulch enables soil to retain minerals and other nutrients. As stated above, there is less loss from erosion. Also, the organic matter in the mulch promotes microbial growth which will incorporate nutrients, preventing them from being lost through normal drainage. As the microbial community functions metabolically, there will be a regular cycle of uptake and release of the nutrients, keeping them in the soil and thus available to your trees, bushes, flowers, fruits, and vegetables.
Fourth, mulch is good for drainage and soil aeration. As mulch decomposes, its organic matter becomes less complex. It integrates with the top layer of the soil. This can lighten some of the heavy, clay-laden soils which are often encountered in Ventura County. A lighter, less dense and well-drained soil provides more much-needed air to the root zone.
Mulch also acts as an insulating layer that prevents the soil from becoming too hot in the summer and too cold in the winter.
Freshly applied mulch also looks good. You must be careful though, to apply mulch properly. Some plants don’t respond to intense mulching. Others need to have their upper roots exposed to the air. Most garden experts, landscapers, or arborists will be knowledgeable enough to be able to recommend the right mulch for your specific needs. Another source of information is the Ventura County Cooperative Extension service which is run by the University of California.
Try to think of your garden’s soil as being equivalent to the skin on your body. Your skin needs to be protected from the weather conditions like wind, sunlight, and aridity. It works best within an appropriate temperature range. It must be nourished, even pampered.
Soil generally gets stepped on, dug into, or plowed up. Property developers will often scrape off and sell for fill the top layer of soil as they prepare a site. This is the same as bruising, or scraping off your flesh. Think of mulch as being the soil’s version of an all-in-one combination of an insulating blanket, a nourishing cream, and a band-aid.
Finally mulch is soft, springy and just plain fun to walk on. Be good to your soil and apply mulch.
Stuart Jacobson, a Camarillo resident, has a Ph.D. in Soil Microbiology from Cornell University. He is a businessman and science writer and has also been involved with beneficial micro-organisms for a long time. For questions or comments, please call (805) 320-3028.