June Issue Extra: Liming Q&A

Q: How is soil acidity corrected?

A: Soil acidity can be corrected when hydrogen or aluminum held by soil and organic matter particles are replaced with calcium or magnesium. Finely-ground limestone is one of the most commonly-used materials. If calcium is the only element needed, calcitic limestone is used. If magnesium is also needed, dolomitic limestone is used.

Maintaining the proper soil pH is as important as fertilizing, watering and pest control. The decision to lime and the amount to apply must be based on a soil pH test and the plants to be grown. Do not guess. Some plants, like rhododendrons, azaleas, and blueberries as well as other members of the Ericaceae family grow best in acid soil (pH 5.0). Most vegetable garden plants grow best in soil with a pH in the 6.2 range. The recommended range for a lawn is between 6.0 to 7.0.

Source: Cornell University Cooperative Extension, Ithaca, N.Y.