Soil - a complex mixture of disintegrated rock, organic material, air, and microorganism - is literally the foundation on which any successful garden is built. Whether you grow flowers, grass, shrubs, and ornamental trees, or vegetables and fruit crops, healthy plants need good soil to thrive and perform well. Fertile, moisture-retentive but well-drained loam soil is considered the ideal. However, most soil requires some kind of basic improvement.
Understanding your soil type is the key to improving it and will enable you to choose plants best suited for it. Simple soil-tested kits can assess acidity and alkalinity; other, equally simple tests can determine soil texture and water content. Once this information is obtained, you can correct nutrient imbalances and enhance structure and drainage, if necessary.