How feeling soil can help you grow a better garden

The gardener's job is to keep the soil in the best condition possible, and that starts with a simple touch. Here's how to tell what kind of soil you have so you can keep your garden healthy and lush.

• The stablest soil component is its framework of rock particles. Soil is classified according to the size of its rock particles. Most soil is a mixture of three sizes: sand, silt and clay.
• Tilth refers to the soil's fitness for cultivation. This is largely a matter of structure — that is, the way in which particles of sand, silt, clay, and humus clump together into granules or crumbs.
• Organic material breaks down in the soil to a dark, nutrient-rich substance called humus.
• In light soil, humus binds sand particles together. In heavy soil, it keeps clay particles apart, allowing room for air and water.
• Laboratory analysis will determine the exact composition of any soil, but you can judge texture on your own. Simply rub a pinch of moist soil lightly between your thumb and forefinger.

• Sand feels harsh and gritty, and its grains scarcely hold together.
• They're the largest soil particles — if they were any larger, they would be called gravel.
• Sandy soil, also called light soil, is easy to work. It drains easily, but with the water that filters through it go many nutrients.
• Growing most garden plants in light soil requires constant replenishment of water, humus, and nutrients.

• Silt particles feel smooth and floury between the fingers. They're smaller than sand and larger than clay.
• Silt packs together with fewer air spaces than sand, which makes for slower drainage.
• It doesn't hold together well, becoming light and powdery when it dries out.

• A pinch of moist loam rubbed between your fingers will be reduced to a rough smear.
• Loam is a medium-textured soil that contains a perfect balance of sand, silt and clay.
• The term is a bit vague but it essentially means "good soil."
• It's friable, which means large clods break down easily into smaller particles.
• Loam holds moisture well. It encourages organic activity, which makes most nutrients available to plant roots.
• With proper management, almost any crop can be grown in loam.
• Humus and other organic matter must be added regularly to maintain desirable levels.
• Liming may be occasionally needed to correct acidity in loam soil.

Soil is defined by the quality and proportions of its components, and a gardener must know what they're using to grow a better garden. It starts with a simple test. From there, you can adapt your gardening to what your soil demands.