Mulching is an easy way to cut down on water loss by plants and soil, as well as to slowly add nutrients back into the soil. Mulches come in organic and non-organic forms; and they affect soil acidity, water retention ability, and nutrient levels—all things that are important to good plant health. Healthy plants are best equipped to survive the drought conditions that we often have.
When considering whether or not to mulch around your plants or trees, some factors to consider are the following:
Cost: What is the least expensive mulch available in your area? You might live next to a dairy, stable, or chicken farm, which could provide a very cost-effective manure. In the Willamette Valley, straw is an easily obtainable mulch. Rice and buckwheat hulls are sometimes available, while most people have a ready source of grass clippings or leaves.
Soil Acidity: Whatever you put on your soil will affect its acidity later on. Mulches that are acid include oak leaves, peat moss, and pine needles. Non-acidic mulches are rice hulls, corncobs, grass clippings, sawdust (elm, hemlock, and locust), and leaves (except oak). Some inorganic mulches that will not affect soil acidity are black plastic, and weed-barrier cloths
Other things to consider when mulching are appearances, fire hazard (hops are the most fire resistant of the organic mulch), durability, and avoiding weeds and disease. Grass clippings will decompose the fastest, while wood chips usually last a couple of years. There is always a danger of introducing diseases, so knowing where your mulch is coming from will ease your concern. Using organic mulch that is weed free or has composted to a temperature of 130-140 degrees will cut down on weed problems from within.
Applying a mulch properly will cut down on problems later on. A mulch needs to be put on at a depth of 4 and ½ to 6 inches for maximum moisture retention. Summer mulching around fruit trees is great for water conservation, but in the fall the mulch should be pulled away from the trunk to prevent damage from mice or other rodents. If mildew or fungus problems arise, remove the mulch and allow the sun to shine on the soil for a couple days. This will kill the disease spores. Then mulch with fresh material