But if it exceeds a half-inch, then it should be managed by core aeration . This process pulls plugs of soil out, which changes the physical composition of the thatch. Eventually, air and water movement into the soil increases, improving root development. At least one treatment per year is recommended. Sloped areas also are prone to browning.
Water usually runs off the slope before it has had a chance to sink in and the lawn dries out.
Aerating the sloped areas helps move water into the soil. It reduces soil compaction, which resists downward water movement. Irrigating slopes with a soaker hose adds water slowly and may improve its penetration. Tree roots compete with grass roots for water. One solution is to water the competitive areas more often or more heavily to compensate for the loss.