How short should I mow my lawn?
“Many folks cut off TOO MUCH grass when they mow. Your lawn suffers when you mow off more than 1/3 of the top growth at a time because you force it to scramble to create more leaf growth to survive. This extra energy to create leaf growth comes at the expense of root growth. If you mow frequently enough so that you never cut off more than 1/3 of the leaf growth you will not “shock” your grass plants and stunt their root system.
See how this relates to your mowing heights with these guidelines. You will probably have to plan on waiting a bit longer between mows this spring to generate healthier root growth:
Final Mowing Height Mow Grass When This Tall Amount You Can Cut to Limit to 1/3
1 inch 1-1/2 inches ½ inch
1-1/2 inches 2-1/4 inches ¾ inch
2 inches 3 inches 1 inch
2-1/2 inches 3-3/4 inches 1-1/4 inches
3 inches 4-1/2 inches 1-1/2 inches
So you see from the chart that the shorter you mow your grass the more frequently you will have to mow to not violate the 1/3 rule. (Since golf courses mow greens short, they have to mow daily to keep from violating the 1/3 rule.) As homeowners, we tend to get on a schedule to mow once a week. If we do not set the mower at one of the taller settings, we will mow off too much with this weekly mowing schedule. This is one of the reasons why lawn experts tell you to mow your grass taller as a way of encouraging you to not mow off too much at a time.
So adjust your mower to leave your grass at around these heights after you mow:
•2-1/2 inches for Bluegrass, Ryegrass and Fine Fescue
•3 inches for Tall Fescue and Buffalograss
•3 to 4 inches for St. Augustinegrass
•1-1/2 to 2 inches for Bermudagrass, Centipedegrass and Zoysia.”