Applying limestone when needed according to soil test results will benefit the garden in two ways. It eliminates some acid in the soil and allows plant nutrients to become more available to plants. Limestone is also a form of fertilizer because it contains calcium, a necessary nutrient for plant growth. Dolomitic limestone also contains magnesium, which is essential for plant growth. Lime effectiveness is increased by grinding, and the smaller the particles, the faster it will become effective in reducing acid.
Pulverized limestone is the most effective form of agricultural limestone.
Other types of lime are sold but must be used at differing rates. All recommendations are based on the use of agricultural limestone. This initial preplant application will normally supply all of the phosphorous and potash needed by most garden vegetables. Nitrogen requirements vary from crop to crop, and heavy rainfall may cause nitrogen to leach from the soil. For these reasons additional nitrogen may be required.