We can’t express enough the importance of cutting your grass on a consistent basis. When you go for longer periods of time without mowing this causes thatch to build up. Thatch build-up can occur when grass grows so tall the mower does not have the full opportunity to mulch the grass. The leftover piles of grass settle and cause a thicker thatch layer. This prevents water, fertilizers, and nutrients from fully getting to the roots. These are all essential things needed to have healthy grass. Another thing to consider is if your mower blades are being sharpened on a regular basis. A mower is unable to fully mulch with dull blades. Hope this helps!