Spongy St. Augustine Lawn Likely Due to Irrigation Leak

A St. Augustine lawn in sun and shade feels spongy and bumpy in winter, with no mole tracks or recent rain. The expert doesn't suspect insects or fungus since grass appearance is unaffected. Instead, an underground irrigation leak is likely, especially if the system runs more frequently in winter. The leak would saturate soil, causing sponginess.

Recommendation: inspect irrigation system for leaks, particularly in zones running in winter.