I find that many people are frequently confused by the terms Compost and amendments.
Mulch is basically any product applied over the area of the dirt, to either cool down or to warm the dirt and at the same time preserve water. It may be more correct to call Compost, area Compost. Mulch is commonly used to keep the dirt cool and to preserve water by preventing the water from evaporating out of the dirt. Mulches can be organic components like decorative bark, compost or even straw. Mulches can also be inorganic like decorative rock, gravel or sand. Amendments are components added into the dirt to improve the physical or chemical make-up of the dirt.
Cooling mulches are very good for organic gardens and flowerbeds during hot weather. Mulch helps keeps the dirt cool and evenly moist, which benefits both flowers and vegetables. Cooling mulches include compost, decorative bark (all sizes and types) and even newspaper. Newspaper can be a problem because it blows real easy, and the colored papers can release ink, which can become a problem.
In your organic garden, straw can also be a good Compost. Straw can be spread out during the summer and then removed and composted at the end of summer permitting the dirt to heat up in the fall. Straw or sawdust can become a problem if left on the dirt too long. Even on top of the dirt, straw or sawdust will deplete the nitrogen out of the dirt.
Besides saving water, mulches have other benefits. Mulches can either cool down or heat up the dirt. In late spring or early summer we can place clear or dark plastic over our garden beds. Just cut holes in the plastic to plant your summer vegetables. The plastic will heat up the dirt and allow organic seeds to germinate faster and the plants to grow faster.
As the summer heats up, cover the plastic with straw or compost or other organic material about three inches deep. This will cool down the dirt during the hot months. When the summer fades into fall remove the organic Compost and expose the plastic, so the dirt will stay warm and your vegetables continue to grow.
That is an example of how to use mulches in your garden and how to extend your flourishing season. Even if you do not use the plastic layer, a cooling Compost in the summer is very important and can benefit your garden.
Mulches can also prevent weeds by suffocating weed seeds. With three inches of Compost, very few weeds will grow and those that do grow can easily be pulled out.