Composting is piling a variety of green and brown organic material in a bin or ventilated container and allowing the material to rot or compost. Once the material breaks down sufficiently, it is applied to the garden. The microbes and decayed organic matter help enrich the soil and build the health of the soil. When a garden has healthy soil, plants thrive as they utilize the nutrients available from the compost. Composting is a popular way of making an organic supplement for the garden, and many experienced gardeners are now teaching composting to other gardeners and schoolchildren.
Begin by explaining the agents of composting and how they stay healthy. For example, worms, organisms and bacteria all need the right temperature, oxygen, moisture, source of nutrition and the right environment in order to function.
Teach student about how worms and organisms break down solid waste during the composting process by consuming the solid waste and converting it into smaller particles that can be used in the garden. Talk about city landfills as well as waste water treatment plants and how they damage the environment and then talk about composting as a solution.
Narrow the talk about the composting process to composting for the garden. Describe how compost, when, it is added to the garden soil, is a source of organic fertilizer and nutrition for the plants. Talk about how it builds soil health and what makes healthy soil. For example, describe good soil vs. poor soil and how organic matter improves soil health.
Show pictures of plants that are grown with and without compost. If time permits, you can grow plants in barren soil and in compost to show the difference in plant health.
Describe or demonstrate how a compost pile is built or how compost is made for the garden. Also, demonstrate the correct formula of green items, such as freshly mowed grass or kitchen scraps, and brown matter, such as leaves that are needed to make good compost quickly. Show how compost is mixed to make oxygen available to the composting organisms and how temperature and moisture levels are important to facilitate the composting process.