For best results blades should be replaced at least once every year.
Arnold has everything you need including lawn mower blades to keep your equipment running at peak performance season after season. 3-in-1 Mower Blade For Walk-Behind Mowers Changing the blades on your lawn mower is one of the best ways to ensure a healthy-looking and clean-cut lawn. 21 in. Mowing with dull blades can tear and rip grass tips leaving the lawn susceptible to disease and browning.