The key to successful gardening... MULCH!

by Don Trotter Ph.D.


ello fellow Earthlings and welcome to the rainy season yeah right. Although it is raining as I am writing this column, it has been a very dry year so far. This week's column is for all of you gardeners that are champing at the bit to get out into the garden and do something during what appears to be a brief wet season this year.

The La Niña weather pattern that has been so widely publicized this year, could very well make it very expensive to garden during our warm season. That is, of course, if the water departments get to raise our rates because of a shortage, either real or manufactured. So while you are contemplating that new rose garden or spring vegetable plot, remember this word: MULCH!

A layer of just about any type of organic matter over the top of your garden soil will do wonders for your water conservation in the yard. Organic mulch or compost insulates the soil from heat, drought, cold, and helps to prevent runoff from our gardens onto the street and out into the ocean or our local lakes. This reduces pollution of these bodies of water, and thus improves water quality at the beaches or from the tap. Those of you that have seen the polluted water signs at Cardiff Reef or other local areas know how distressing this can be, especially if the waves are good. Those of us that like to recreate or fish in the local lakes know that the funky green color and murkiness mean that swimming or water skiing is a risk to our health. A lot of valuable work is being done by environmental groups like the Surfrider Foundation and the Clean Oceans Campaign. These groups are attempting to raise our awareness of the fragile nature of the oceanic ecosystem. I have a helpful solution to a small part of this problem: MULCH!

By mulching our garden soils, we reduce and sometime actually eliminate runoff water from carrying nutrients from fertilizers and chemicals from pesticides down to these bodies of water. Mulch also acts as a sponge for excess moisture, holding it in reserve for the plants in your garden. These organic materials also provide a food source for a myriad of beneficial soil organisms that will slowly but surely improve the overall quality of your garden soil.

The trillions of microbes that inhabit soils use organic matter for fuel in order to form humus. Humus is a material that stabilizes soil pH, makes soils more loose and friable, allows for better transmission of nutrients to plants, and helps plants to resist disease more effectively by the formation of salicylic acid. Mulch helps to feed microbial activities in soil that also compete with disease organisms by a process known as "competitive exclusion." This means that beneficial bacterial and fungal activity is increased, and pathogenic or pest varieties of bacteria and fungi are reduced because of the presence of a continuous source of organic matter to feed upon. So when you apply mulch to your garden, you're fighting diseases and making your entire garden more pest resistant as well.

Pest insect and disease pathogens happily attack and devour stressed plant material. When plants are healthy from the availability of natural sources of nutrition, they can resist attacks by these organisms more effectively. This will allow you an opportunity to spend less money on insecticides and fungicides, while attracting pesticide sensitive beneficial insects into the garden to clean up the small pest populations. Nature did not intend for your cabbage to be entirely ravaged by imported cabbage worms. She created the Trichogramma wasp (don't be afraid, they don't sting) to parasitize these worms so that you can eat.

The problem is that beneficial insects are normally very sensitive to pesticides, and their populations do not recover as quickly as pest species. So be aware that when you apply pesticides to kill a single insect pest, your not just wiping out the problem. Chemical runoff is also a big problem for our local waters. So be kind to the garden while your making our waters cleaner.

Organic mulches can be found almost everywhere. Most reliable garden centers handle a variety of good choices. My favorite is "Greenwaste mulch." Greenwaste is the recycled yard waste that you put into that special bin every week. There are several good sources for greenwaste mulch around the county. Greenway compost is the one I most highly recommend. Give Carolyn Chase a call at (760) 723.6648, and see what they can do to help you save money in your garden while helping to improved all of our environment. See you in the Garden!

  The City Dept. of Environmental Services offers free mulch at the Miramar Landfill; call (619) 573-1420. Got Questions? Call the Doc toll-free at (877) 535-7963, fax him at (760) 632.8175, or Email your questions to Don Trotter's columns on environmentally responsible gardening appear nationally. Look for Don's new book Natural Gardening A to Z coming this July from Hay House Publishing