You may have areas in your lawn that look stressed and then turn brown when the Summer temperatures begin to rise. These are the most common reasons:
-Localized dry spots
Even the best irrigation systems have areas that do not receive the same coverage as other areas. Once an area is dry it can become hydrophobic or hard to get wet again. These localized dry spots require more attention. Take the time to hand water these areas and ensure the water is penetrating. A soaker hose and a pitchfork are great tools.
-Poor soil conditions
It is always the same trouble areas that look stressed and turn brown first. These areas often have compacted or rocky soil conditions. These areas could benefit from aeration, lime application and over-seeding in the Spring or Fall. Top-dress with peat moss at the time of aeration for improved moisture retention and soil tilth.
-Transitioning annual grasses
Over time annual bluegrass (Poa annua) begins to establish in our lawns. There are many varieties of annual bluegrass that transition in and out at different times of the year. Poa has shallow roots so it is common to see drought stressed transitioning brown patches in the Summer.