Testing Your Soil
There are two main types of soil particles: sand and clay. Sand particles are relatively large and water drains freely through the spaces between them, while clay particles are tiny and trap moisture in the minuscule gaps. This explains why sandy soils are dry and clay soils are moisture-retentive. Most soils are a mixture of both—tending to lean toward one or the other—but the ideal is loam, which contains almost equal measures of sand and clay. Loam retains enough water for plant roots to use, but also drains away excess moisture to prevent waterlogging. Test your soil type by digging some up and rolling it between your fingers.