Visible grass roots on the surface of your lawn can be caused by a number of problems, many of which are interrelated. Roots can become visible with excess thatch build-up, insufficient water and nutrients reaching the roots and from soil erosion. Grass roots can also be exposed by chemical or sun burn and with too low of a mowing height. Each of these conditions can be treated effectively with basic lawn care practices. Used in combination, a healthy lush lawn can be restored.
Remove excess thatch, stolons, runners and shallow root material by making two passes over the lawn with a de-thatching rake. Make the second pass, pulling the rake at a 90-degree angle to the first pass for an even thinning. Collect the loosened dead grass material and discard.
Water the lawn deeply to restore moisture at the root level and be sure to apply at least 1-inch of water to the lawn every week. Water more frequently in warm and dry climates.
Cast a 1-inch to 2-inch thick layer of good quality compost evenly over the entire expanse of lawn to provide a good soil base for new growth, insulation for roots and nutrients for the soil.
Feed the lawn in the early spring, early summer and early fall with a nitrogen rich granular lawn fertilizer such as a 25-4-12 formulation to boost green top growth development to fill out the lawn. Apply according to the product label directions but do not exceed an application rate of more than 2 lbs. per 1000 square feet.
Raise the mowing height on the lawn mower blade to at least 1-1/2-inches to prevent the roots from being exposed and drying out easily.