The height and frequency with which you mow the yard will have a large impact on its overall health and appearance. Northern grasses are ideally cut to 2.5 to 3 inches.

• Grass blades are solar panels. They need an optimal surface area of 2.5 to 3 inches to create good photosynthesis.
• Grass roots are only as tall as the blade. Allowing grass to grow up to 3 inches ensures a deep, thick root mass. In turn, the grass aggressively utilizes nutrients and chokes out weeds.
• Tall grass is more resistant to pressure from drought and insects, as it can withstand more damage and lose more root mass without negative effects. Moles will actually tunnel below the root base and not leave dead runs.
• Taller blades shade the soil surface, depriving weeds of sunlight and preventing them from growing.
• Taller grass suspends seeds, like dandelions, above the soil and prevents them from getting to the soil to germinate.

Here are some general guidelines to follow:

• Mow often enough that you do not remove more than 1/3 of the blade.
• Following the above recommendation, leave the clippings. They will dry up and return nitrogen and phosphorous to the soil.
• Mow tall, to the optimum height of the grass (2.5 to 3 inches).
• Mow in alternating patterns.
• Keep the blades sharp.