What is Mulch?
The word 'Mulch' has its roots in German. It comes from the word 'molsch' which means 'beginning to decay'. This is probably used in reference to the first types of mulch that were biodegradable. Mulch is a thin layer of any substance that is spread over the soil. It is used to mimic the conditions that one sees in the forest.
Gets Plants Through Extreme Weather.
During dry spells, mulch can save plants. It acts as an insulator, keeping the soil cool and moist in summer. Vegetables that have their roots in cool soil will be more vigorous and less stressed by heat. In winter, mulch can keep the soil from freezing, an advantage for those who have root crops in the ground. The exception to this is in cold climates, where gardeners either avoid mulching so that the ground can soak up all of the summer sun's rays, or mulch with black landscape fabric or plastic to trap heat.
Keeps Soil Moist Longer.
Water evaporates much more slowly when the soil around the plant is covered with mulch. That means more water for the plant - and less watering for you.
Keeps Down Weeds.
Organic mulch keeps the soil beneath it shaded, loose, and moist. If weed seeds manage to germinate in the dark and rise above the mulch, they are easily uprooted by pulling. But beware that you don't use mulch (or natural fertilizer like chicken litter) that can introduce seeds into the garden.
Keeps Plants Clean.
A mulch blanket under your plants keeps soil from splashing onto the leaves, which in turn helps prevent disease (especially on tomatoes). Lettuce, spinach, and other greens will be a lot easier to wash, too.
Becomes Valuable Humus.
As organic mulches gradually decay, they increase organic matter and, eventually, humus in the soil. Humus is the holy grail of organic matter, as it is the point at which such materials can no longer decay. Instead, they act like a sponge to hold moisture and nutrients. This is the ideal growing environment for most plant roots.
When and How to Apply Mulch
Mulch can be added at any time, but autumn or spring are most typical. An autumn application in the veggie patch will help with soil enrichment for spring seedlings. Perennials that have borderline hardiness in your area can also benefit from the insulating effects of a heavier mulch layer atop their roots in late autumn. In all areas, spring applications will best help with moisture retention and weed control, while also enriching soil. An additional midsummer application, to still producing vegetable plants, is a good idea if earlier applications are well-deteriorated.
Beneficial mulches can be applied around existing plants or placed ahead of time and planted through. A two inch layer is sufficient around plants; thicker layers can be used in unplanted areas. Water the soil well before placing the mulch and do not mulch up against stems and trunks, to avoid root issues. A wheelbarrow and a shovel, or garden fork, are often the most helpful tools for getting the mulch to where it is needed, especially for large areas. A bucket can also be very handy for sprinkling mulch around plants and a hand-size garden fork for spreading in tight quarters.