What is a sign of excessive thatch buildup in turf?

A sign of excessive thatch buildup in turf is the spongy feeling when walking on the surface. Thatch, which is a layer of organic debris such as dead grass, roots, and other plant material, can accumulate if the turf is not managed properly. When thatch becomes too thick, it can create a cushioning effect that results in a spongy texture underfoot. This condition not only indicates that there is an excessive buildup but can also lead to various turf problems such as reduced water infiltration and nutrient availability, making it crucial for turf managers to monitor and manage thatch levels appropriately.

The other options can be associated with different issues in turf health. For instance, brown patches may indicate fungal diseases or other problems rather than thatch specifically. Increased water retention could be caused by various factors, including soil compaction or poor drainage, rather than merely the presence of thatch itself. Lastly, higher insect activity is generally a response to other stress factors in the turf, such as drought or disease, and does not directly indicate thatch buildup. Understanding these distinctions is important for effective turf management.