A little soil common sense will go a long way to helping you understand how to care for your garden. All soils are not the same; they differ in many ways, including texture, fertility, and pH (acidity/alkalinity).
Soil texture is the look and feel of your soil. It's determined by the size of the soil particles. At one extreme is beach sand, with soil grains so large you can see the individual particles. Not much grows in sand. Water runs right through it, and in direct sun, it gets so hot you can hardly walk on it in bare feet.
At the other extreme is clay, such as the red and gray clay found in many parts of the country. Clay is made up of tiny, flat soil particles that turn into a gooey mess when wet and resemble cracked brick when dry. Although naturally fertile, clay is slow to warm in spring and water doesn't readily drain from it, meaning gardeners get a late start in spring.
The ideal soil is loam, which contains a mixture of particle sizes. Loam drains well, yet also retains water, and is easy to work.
However, no matter what type of soil you have, adding organic matter -- material that was once alive -- will improve it. Leaves, grass clippings, pine straw, and vegetable wastes from your kitchen are examples of organic matter. Applied at least one month before planting your annual garden and worked into the soil, organic matter will decompose and provide nutrients to plants. An even better way to add organic matter is with compost. Compost is a gardener's best friend: It helps break up clay particles, allowing water to drain better. In sandy soils, it binds the grains together to retain moisture and fertility. Compost can be applied as a mulch to perennial plantings.
A healthy soil, loaded with compost, will be naturally fertile. Underground, plant roots are mining the soil, turning organic minerals into leaves, flowers, and fruit. While light and water are essential for this process, there are also some major nutrients that must be in place for proper growth.
Although healthy soils may have plenty of these nutrients available, on less-than-ideal soil plants may need supplemental feeding. And even plants on healthy soils can sometimes benefit from additional nutrients.
The form in which the nutrients are applied is of utmost importance. Although synthetic fertilizers provide precise amounts of specific nutrients, they lack micronutrients and soil-building microorganisms, and because they release nutrients all at once, they promote a flush of growth that is weak and susceptible to disease. Also, the excess nutrients leach away, polluting nearby waterways. The opposite is true of compost. It provides a slow, sustained release of nutrients that plants use as needed.
Compost provides so many benefits that every gardener should consider taking advantage of this easy-to-make soil improver.