Adding a year-round mulch at the base of your trees is a good idea. It will help your plants weather all sorts of conditions. A good mulch cover will be about 3 inches deep after it settles. An organic mulch, such as wood chips, shredded bark, or cocoa hulls, not only keeps an area free of weeds and helps conserve moisture but also improves the soil by adding organic matter as it deteriorates. Here are some mulching tips to keep in mind. Keep the mulch away from the trunk. Mulch should not touch the stems of your plants, because di-rect contact can encourage fungal disease and give voles and insects easy access to the young woody plants. Mulch a large enough space. The mulch layer should extend as far as the canopy of a tree. Root systems often spread 3 to 4 times the width of the canopy. Banish grass growing in the mulch. Grass roots compete with and slow the growth of young plants. Use herbicides with caution, however; they may damage young plants. Avoid too much mulch. Don't lay more than 3-4 inches of mulch around your plant. Too much mulch can keep water and air from reaching plant roots. Deep mulch also can provide a home for damage-causing insects and rodents.