There are basically five reasons to mulch:1. To prevent weeds
2. To keep the roots cool in hot weather
3. To slow evaporation of moisture from the soil
4. To protect your plants from the winter winds
5. To add nutrients to the soil (when using organic mulches)
However, there are some rules to mulching:
1. Don’t put a thick layer around seedlings or mulch over seeds. It will act like a blanket and discourage the seeds from sprouting, which is a good thing if the seed is of the weed variety, but not otherwise.
2. Keep mulch pulled away (about 1 to 2 inches) from tender sprouts. Organic mulch will decompose. And when it goes through the decomposition phase, heat is created. If it gets too hot, the heat can kill young plants.
3. Think brown. Although adding grass to a compost heap is great, mulch created from fresh grass clippings can be deadly to your plants (young and old).
4. Some mulch contains seeds that can spread rapidly like Hay. Avoid them if at all possible or your beautiful garden will soon become a hay field.