The answer to 'why is my sod installation' is that there are several common causes for problems with a new sod installation, including improper soil preparation, poor sod quality, incorrect installation techniques, and lack of proper maintenance after installation. Symptoms may include bare spots, uneven growth, and yellowing or browning of the grass.
If the soil was not properly prepared before laying the sod, the roots will have difficulty establishing and the sod may not take hold. The soil should be tilled, leveled, and amended with compost or other organic matter to provide the right nutrient balance and drainage. Sod that is of poor quality or not suited for your climate can also fail to thrive. Improper installation techniques like not staggering the seams or not pressing the sod firmly into the soil can lead to gaps and uneven growth. Finally, new sod requires regular watering, mowing, and other maintenance in the first several weeks to become established.