If you have a look at a well tended garden around a home patio, you can assume a lot of mulch has made the garden that healthy. Any experienced gardener will tell you that compost and mulch are the keys to good gardens.
This isn’t “gardening mythology”. It’s quite right.
The reason is that composting breaks down materials into a chemical state which is easily accessible to the plants. Topsoil is basically a mix of sand and chemically broken down plant materials. In nature, fungi, bacteria heat and water are the main agents of the initial breakdown of materials.
All of these agents are naturally present, and the process of composting is based on them. Earthworms, if present, further refine the broken down materials, which is also a good way of spreading the nutrients for the plants efficiently.
Many formulas exist for compost, including various levels of added nutrients. These are often excellent mixes, but in practice, good compost is a balanced mix of natural materials which is good enough for any gardening purpose. The basic requirements for most plants are nitrogen, potassium and phosphorous, which are common to all plants and released by composting.
There are levels of composting which determine the nutrient values of compost. The rule is that the more composting, the stronger the mix becomes as nutrient value in the garden. The extra composting does reduce the volume of the materials, however, so if you’re intending to mulch a large area, the basic composting approach is usually the simplest and most effective approach.
Basic garden compost is comprised of green material, mixed with fine chopped fiber. The fibers act to help bind the soil, and also release nutrients as they decay. You can also use vegetable scraps, weeds (remove any seeds) and prunings. Lawn clippings are OK, provided they’re well mixed in with bulk materials. They produce very little actual compost, but add valuable water to the mix.
Do not use any animal waste materials, particularly meats. Manure may be used, but only in small ratios, well mixed in.
Home gardeners usually use containers like turning bins, which are efficient for aerating the mix and promoting the growth of biological agents like fungi and bacteria. This is a chemical, rather than a heat-based process, although you’ll notice the compost does get warm, which is a result of the chemical activities. The greenery also provides moisture, which further promotes dissolution of the materials and encourages fungi and bacteria.
The basic compost is a soft, fibrous brown or blackish humus-like mulch. This material, when added to the soil, is further broken down by soil bacteria and fungi, and acts as a sort of slow release fertilizer, providing nutrients steadily. This type of compost also acts as good top dressing and a general soil and environment improver. The compost effectively provides a layer of extra soil as it’s assimilated into the garden. It even acts as a temporary weed mat, preventing weeds from sprouting.
Your plants will appreciate the pampering.