Although Grinding gets rid of a tree stump quickly and efficiently, it can negatively affect the soil. The grindings left behind robs nitrogen from the soil, and the lack of nitrogen can keep grass from growing in the area. The large amount of grindings left from the stump may take years to decompose on its own preventing the soil from returning to normal nitrogen levels. However, several ways exist to help speed up the process.
Growing grass requires an abundant source of nitrogen within the soil. Without proper amounts of nitrogen, grass appears stunted, yellow, and patchy in some areas where grass will not grow. The lack of vigorous growth enables weeds to invade the lawn, making it harder for the grass to thrive as the weeds compete for nutrients and water.
When you want to plant grass immediately where a stump was removed, you must mitigate the nitrogen-deficiency damage by removing as much of the stump grindings as possible. If large roots were ground out, dig out the stump grindings left along the root lines as well. If you are not able to get every last bit of the stump grindings out no need to panic, it's ok! A small amount does function as a handy soil amendment in dense soil. Just keep in mind digging out as much as possible will prevent it from affecting the nutrient composition of the surrounding soil. Add topsoil to fill the hole left from the stump removal.
Adding nitrogen-rich fertilizer to the area where the stump once stood can help prepare the soil for grass - about 1 ounce of a fertilizer such as a 20-10-10 blend is sufficient for 4 square feet of soil, or a stump that was 2 feet in diameter. Using a mixture of quick-release nitrogen and slow-release versions gives the soil an immediate nitrogen boost while ensuring a continuous supply after the quick-release nitrogen depletes. Mixing the fertilizer with the topsoil should enable grass to grow immediately if you removed the stump grindings. If the stump grindings are mixed with the soil, it could take up to one year for the fertilizer to provide sufficient amounts of nitrogen to support grass development.
Testing the soil provides information on several essential nutrients but usually not the nitrogen level. The levels are fluid and sometimes have large inconsistencies depending on how deep the sample is taken from, how much it rained recently, and the soil composition. You can get home testing kits from places like Home Depot or Menards. PH test results let you know whether or not the soil is at the proper level of acidity to allow grass to absorb nitrogen. Grass grows best at a soil pH of 6.0 to 7.0, and soil releases nitrogen most efficiently at a neutral pH of 7.0. Adding lime raises the pH level while adding sulfur or pine needles lowers it. The amounts to add depend on your soil's type, the current pH level and the desired pH level. If, for example, Justin's soil is currently at a pH of 8.0, then add 3/10 pound of elemental sulfur per 10 square feet of soil to lower the pH to 6.5. To change the pH from 6.0 to 6.5 in Justin's soil, add 4/10 pound of ground limestone per 10 square feet of soil.