Soil is one of the most important aspects of how successful a garden is. A bad soil will not have the nutrients nor the structure to support plant life. Adding compost to soil both improves its structure, allowing for better water retention and air movement, but also provides essential nutrients.
Soil types are determined by the composition of particles within the soil. The three main particle sizes are sand, silt and clay. Sand is the biggest particle. It is gritty and allows for lots of water drainage. Sand soils do not hold water or nutrients very well. Silt soils are made of medium-size particles. These feel soft or floury when wet and in the hand. These soils retain too much water. Clay soils have the smallest particle sizes. These feel sticky and are dense when wet. Clay soils do not allow water movement. The ideal soil type has a combination of all three, but some plants require modified soils.
Compost is a soil amendment used in soil that does not have the right structure for growing plants. Compost is made of decomposed organic matter. It is made by combining organic waste into piles that either decompose naturally with the help of microorganisms, or composted by worms. Organic materials include yard waste, kitchen waste and bulking agents such as wood chips, shredded paper or cardboard. When added to the soil, compost relieves compaction.
Yard trimmings are a source of organic compost material for the garden. Adding leaves and grass to the soil of the garden increases water drainage and adds microorganisms to the soil as the material breaks down.
Scrap wood from log cutting and sawdust from housework is a valuable soil amendment for the garden. Wood scraps layered over the topsoil of the garden act as a mulch that helps reduce water evaporation and keeps the soil beneath moist. Mulch buried in the dirt adds small amounts of nitrogen as it composts, and also increases water retention and air circulation in the soil.