Do You Fertilize Fresh Sod?

Preparation

• Preparing the sod area includes removing rocks and debris and cultivating the soil to a 4-inch depth. Before laying sod, fertilize the prepared soil. Usually soil samples are taken and submitted to a local university extension for testing. Fertilization is then based on soil test recommendations. Fertilizer mixes that are normally used prior to laying sod are 10 pounds of 5-10-5 fertilizer or 20 pounds of 10-20-10 fertilizer.

Nitrogen

• Three macronutrients essential to lawn growth are nitrogen, phosphorous and potassium. Each nutrient contributes to a portion of the grass' overall health. Nitrogen encourages leafy, foliar growth. It is applied to fresh sod in small amounts. Apply nitrogen 24 hours after sod has been put in place. Since sod is heavily irrigated, delaying nitrogen application prevents the nutrient from being flushed from the sod's root system and does little good.

Phosphorous and Potassium

• Phosphorous and potassium are essential to root development. They also protect lawns from disease and encourage cold hardiness. These nutrients must be applied to soil prior to sodding. When applied after sodding, the nutrients are not able to push past lush vegetation and into the root zone. The only way a lawn can take in these nutrients is through the root system, so applying phosphorous and potassium prior to seeding is a necessity.

Lime

• Agricultural lime raises soil's pH level. Sulfur lowers soil's pH level. A high pH level is alkaline and low pH is acidic. When soil is too acidic or too alkaline, chemicals are not able to interact effectively and plants are unable to absorb necessary nutrients. Bringing soil close to a neutral range allows grass roots to take in minor nutrients like calcium and magnesium. Calcium and magnesium help support blade structure and vigor. Apply lime or sulfur prior to installing sod. Lime and sulfur cannot be applied to fresh sod because it damages foliage growth.

Considerations

• Fertilize established lawns in late spring and fall. Irrigate the lawn well prior to applying fertilizer. Without proper hydration, lawns are unable to process extra nutrients. Fertilizing dry or drought-damaged lawns only increases the lawn's problems.