Soil Fertility 101 (cont)
By: National Gardening Association Editors
People are most comfortable when the temperature is in a certain range 65° to 75° F. Plants do best when the soil is in a range between being acid and alkaline. Instead of being expressed as degrees Fahrenheit, soil balance is expressed as pH to measure its acidity or alkalinity. Most plants do best in a range of 6.5 to 7.5 pH. The pH scale goes from 0 (acid) to 14 (alkaline), so most plants like to be in the middle.
There are exceptions. Plants like azaleas, blueberries, and heath like more acidic soil.
In the eastern United States and the Pacific Northwest, the soil tends to be too acidic for best plant growth. People there add ground limestone (or dolomitic limestone) to the soil or spread it on lawns to balance the soil. Adding lime saves money because it is inexpensive compared to fertilizers. In acid soils, the nutrients in fertilizer can be "locked up" and not available to your lawn and garden, so it pays to balance the soil first.
In the West and Southwest, soils tend to be alkaline. Sulphur is added or spread to bring them into balance.
Testing your soil
You can do a simple soil test yourself or have a more complete one done by a private lab or cooperative extension service at your state university. It is one of the most important things you can do to be a successful gardener.
A simple test kit, available from your garden center, will show you the pH balance. Often this is litmus paper, which turns color during the test and allows you to match your test with a color scale.
Your garden center may also have kits that allow you take several soil samples from around your yard, send them off, and receive a report on pH and fertility...a guide to the need for nitrogen, phosphorus, and potassium.
Remember, in gardening everything is based on healthy soil. The more you know about your soil, the more successful you will be.
Photography by the National Gardening Association.