How often should I mow my lawn?

FAQ
Question: 

How often should I mow my lawn?

Answer: 

Kentucky bluegrass lawns should be mowed at the height of 2½ to 3 inches in spring and fall.  Set the mower blade to a height of 3 to 3½ inches during summer. 

As a general rule, never remove more than 1/3 of the total leaf surface at any one mowing.  For example, to maintain a lawn at 3 inches, the grass should be mowed when it reaches a height of 4½ inches. 

Mowing frequency is based on the growth rate of the turfgrass.  Weather conditions, cultural practices (such as fertilization and irrigation practices), and other factors determine the growth rate of turfgrass. 

Kentucky bluegrass and other cool-season grasses grow quickly in spring when weather conditions are favorable.  The growth of cool-season grasses slows in summer and then picks up again in fall.  Fertilizing and irrigating the lawn on a regular basis promote turfgrass growth.  In spring it may be necessary to mow every 4 to 5 days, possibly only once every 1 to 2 weeks in summer, with more frequent mowing again in the fall.