Mulch is a layer of material (like bark mulch or pine straw) laid on the soil surface to discourage weeds from germinating, to prevent moisture loss, and to improve soil fertility. In most cases it is also aesthetically pleasing. The most natural mulch and pine straw is a loose organic material applied in a layer, three inches deep or more. In nature autumn leaves provide a blanket of organic matter, but in the garden we can use anything from chipped bark to cocoa shells to garden compost, leaf mold or pine straw.
Mulch and pine straw help to retain moisture in the soil by preventing water from evaporating from the surface layer. Dark colored mulches can also help raise the temperature in the soil early in the season and promote rapid root growth in spring as well was foster healthy plant development, and control erosion. Organic mulch and pine straw are popular because they are easy to use, they are adaptable and they help improve soil fertility as they slowly decompose. Meanwhile they are incorporated into the soil by earthworms and other soil dwelling creatures.
You will need to replace an organic mulch about twice a year. It is important that the soil is warm when you mulch. The bacteria within the soil and the mulch are constantly releasing nutrients and if the temperature is too low this process will stop. Putting a good mulch on before the winter sets in reduces the temperature changes in the soil that cause stress to perennial plants so they will thrive better.
The benefits of mulching will be easy to see. The soil remains healthier and has a constant supply of new nutrients being gently released at nature’s own pace. Also weed control is much easier. The most beneficial effect is keeping the moisture where it is most needed. Soil under mulch is generally cool and moist to the touch. You won’t have to water as often and it maintains a constant, healthy environment for your plants even during the long hot summer months.