Mowing Height to Promote Grass Root Growth

Lawn grass height is a direct reflection of grass root depth.

Ideal mowing heights vary with individual grass varieties. In general, higher cut heights promote better root growth compared to lower cut heights. Healthy roots supply more moisture and nutrients to the grass, which helps to create a dense, green foliage.

Theory

Top growth is a reflection of root depth. Over time, if you cut the grass slightly higher, the root systems will be slightly deeper, creating a healthier turf grass. Conversely, cutting the top growth lower leads to shorter roots which can make the grass weak and vulnerable, according to the University of Rhode Island.

Warm Season Grass

Warm season grasses are generally cut slightly lower than their cool season cousins. Cut heights average 2 to 3 inches for the majority of warm season varieties. Conservatively cutting the lawn near the upper range of 3 inches will help promote root growth.

Cool Season Grass

Cool season grasses are generally cut between 2 1/2 to 3 1/2 inches depending on the individual variety. By cutting the grass to the upper range of 3 1/2 to 4 inches the grass will remain aesthetically pleasing and the root system will be slightly deeper.

Advantages

The primary advantage of higher cut heights and deeper root growth is improved resistance to drought, disease and weeds. Additionally, higher cut heights provide more leaf surface area available for photosynthesis, which strengthens the overall plant.

References

• University of Rhode Island: Lawn Mowing
• University of Maryland: Home and Garden Center