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