Taking Care Of Your Roots
Deep watering followed by a brief moisture stress period can result in a deeper root system. Watering too often can result in shallow root systems, and cause your lawn to die under severe heat stress periods. The deeper your roots are, the more likely your lawn will survive such heat stresses as well as the dry winter months.
Mowing is another factor that affects root growth. The higher the mowing height, the more green tissue there is to catch sunlight, which increases the root mass and root depth. A lower mowing height reduces the ability of the grass to absorb sunlight which in turn lowers the production of nutrients and results in a shallower root system. Taller grass also helps to retain moisture in the soil by keeping the sun off the soil and the blades shade each other.
Rooting will increase with sufficient and timely applications of nitrogen (fertilizer). Grass that is deficient in nitrogen will have a limited root system. It is also important to note that too much nitrogen will cause excessive growth, which in turn will quickly deplete storage of nutrients in the roots.