Lime is a rock powder used to raise the pH of soils high in acidity. An application of lime "sweetens" a soil -- i.e., makes the soil more alkaline. The capacity of lime to sweeten ground to which it is applied also makes it useful for battling outdoor pet odors.
Caveats about using lime:
- There are different kinds of lime, not all of which are preferred for landscaping purposes. As Charlotte Glen of the North Carolina State extension notes, agricultural or "garden" lime is made from calcium carbonate, and dolomitic lime from dolomite; both are suitable for landscaping use. But slaked lime and quick lime "are not recommended for lawns and gardens."
- Have a soil test done before you even think about adding lime. Prior to taking any action, have the test results and subsequent recommendations explained to you if you don't understand them fully.
- Remember, when adding such minerals to the soil, you are playing with chemistry. Unless you're a chemist and really know what you're doing, err on the side of caution -- don't add lime indiscriminately, thinking, "it can't hurt anything."