At ER Lawn Care, we set our mower decks to a height of 3.5 to 4 inches, depending on the season. For example, we use a deck height of 3.5 inches from April to May and the middle of October through the end of November. In June and the remaining summer months, we increase that deck height to 4 inches.

A mower deck height that’s too short can scalp the turf beneath the grass and cause lasting damage. Cutting more than one-third of the grass at a time can stress the grass out tremendously. At the same time, grass that’s too tall is susceptible to both disease and further weed growth.

As such, we’ve found that 3.5 to 4 inches is an ideal cutting height for all-season care.