Good mowing is important. Blade height should normally be 2 1/2 – 3 inches, longer in predominately shade areas. Vary your mowing patterns and sharpen your blade frequently. Final fall mowing should be at 1 1/2 inches to promote root growth. Preferably, clippings should be left on the lawn, as they quickly decompose and add both mulch and nutrients to the soil. Most, if not all, thatch build up is caused by poor watering practices.