Follow the one-third rule for every mow

Never remove more than one-third of the grass blade height in a single mowing. If your target height is 3 inches, mow when the grass reaches 4 to 4.5 inches.

Why It Works

Removing more than a third shocks the plant, reduces photosynthesis, and weakens the root system. It also produces heavy clippings that clump and smother the turf underneath. The one-third rule is the single most important mowing guideline endorsed by virtually every university extension service.

Tips

• During peak spring growth, this may mean mowing every 5 days instead of weekly.
• If you fall behind and grass gets too tall, mow it down in stages over several days rather than taking it all off at once.