Salt damage occurs when salt accumulates in the soil to damaging levels. This can happen in two ways: either the lawn is not receiving enough water from rainfall or irrigation to wash the salts from the soil, or the drainage is so poor that water does not pass through the soil. In either case, as water evaporates from the soil and grass blades, the salts that were dissolved in the water accumulate near the surface of the soil. In some cases, a white or dark brown crust of salts forms on the surface of the soil. Salts can originate in the soil, in the irrigation water, or in applied fertilizers.
The only way to eliminate salt problems is to wash the salts through the soil with water. If the damage is only at a low spot in the lawn, fill in the spot to level the lawn. If the entire lawn drains poorly, improve drainage by aerating according to the directions in Compaction; or improve the soil as described in Soil Types. If the soil drains well, increase the amount of water applied at each watering by 50 percent or more, so that excess water will leach salts below the root zone of the grass. Fertilize according to the instructions in Fertilizing.
