The obvious answer to drought stress on lawns is to apply water.
Deep, infrequent watering to the depth of the root system is the
ideal situation. This should be done when lawns show the first
signs of drought stress, such as wilting, darkening color, and
footprints remaining after walking across the lawn. A variety of
factors, including budgets, site factors, and watering
restrictions all might make this impossible. When an organic
lawn care program is in place, the organic matter used to
topdress and the resulting improved soil structure will likely
extend the greening period farther into the summer before the
lawn goes dormant. This improved soil structure will also allow
the grass plant to take full advantage of the moisture present
and food uptake into the grass plant. Good soil structure will
allow the lawn to return to active growth and recover quickly.
Once cool-season turfgrasses have gone dormant (stopped active
growth, turned off-color) it's best to leave them in that
condition rather than watering