Does Mowing Height Matter in Grass?

Mowing your lawn can often feel like a monotonous weekend chore, so it's tempting to mow your grass as short as possible to delay your next session. However, cutting your lawn too short may do more harm than good. The height at which you mow significantly influences the appearance and overall health of your grass.

Proper lawn mowing can make the difference between a lush, healthy lawn and a patchy, stressed one. Understanding how mowing height affects your grass and employing the correct practices can help you maintain a beautiful lawn year-round.

Key Takeaways

• Maintaining the correct mowing height helps promote a healthy lawn by allowing grass to photosynthesize efficiently, grow deeper roots, and retain moisture. Following the one-third rule ensures grass blades aren't cut too short, which can stress the lawn and make it more resilient against environmental stress.
• Cutting grass too short, or scalping, weakens the plant by reducing its ability to photosynthesize, making it more susceptible to weeds, drought, and disease. Additionally, mowing too infrequently can lead to grass being cut too short at once, further stressing the lawn.
• Patience is key when mowing newly planted grass plugs. Wait until they have fully rooted, about 3-4 weeks, before mowing, and follow proper height guidelines to avoid uprooting or damaging the new grass.

How Mowing Affects Your Lawn

Regular mowing is essential for maintaining a healthy lawn, and so is mowing at the proper height. Grass blades play a crucial role in photosynthesis, converting sunlight into the energy your lawn needs to thrive. Cutting too much at once can reduce the plant’s ability to generate food, leading to weakened grass.

A key mowing tip is to follow the one-third rule, which means never removing more than one-third of the grass blade length in a single mow. This rule allows the grass plant to maintain enough surface area to absorb sunlight, which supports growth and development. Over time, lawns mowed properly at the right height will develop stronger roots, better resilience against drought, and fewer issues with pests and diseases.

The Benefits of Maintaining Proper Mowing Height

Maintaining the correct grass length for warm-season grasses like Bermuda, Zoysia, and St. Augustine is key to promoting overall lawn health.

• Prevents Soil Compaction: When grass is mowed at the proper height, it produces thicker, denser growth. This dense grass cover helps cushion the soil from heavy foot traffic or equipment, reducing the risk of soil compaction.
• Improves Moisture Retention: Taller grass blades provide more shade to the soil, reducing evaporation and keeping the ground cooler. This results in the soil retaining more moisture for longer. Consequently, grass cut too short exposes the soil to direct sunlight, drying out the soil more quickly. Maintaining the proper grass height helps the lawn conserve water naturally.
• Encourages Deeper Root Growth: When grass is kept at an appropriate length, the plant can focus more energy on growing deeper roots. A deeper root system allows the grass to access water and nutrients from deeper within the soil, making the lawn more resilient to drought and nutrient deficiencies.
• Reduces the Need for Watering and Fertilizing: By following the one-third rule, you avoid putting stress on the grass plant. Stressed grass requires more frequent watering and fertilizing to recover and grow. Healthy grass retains moisture better and can access nutrients more efficiently, reducing the need for frequent watering and fertilizing.

READ: What Goes First: Mowing or Fertilizing?

Overall, keeping warm-season grasses at their optimal length creates a stronger, healthier lawn that requires less intensive care while maintaining its resilience against environmental stress.

Is it Better to Mow High?

The ideal height for your lawn varies depending on the grass type. Warm-season grasses like Bermuda, Zoysia, and St. Augustine perform better at a slightly shorter height, generally between 1 to 2.5 inches, compared to common cool-season grasses like perennial ryegrass and tall fescue.

During certain seasons, particularly in the peak of summer, your lawn may benefit from cutting the grass higher than usual. Longer grass helps shade the soil, reducing water loss and keeping the roots cool. As a result, lawns mowed at the highest setting possible in hot weather are less likely to suffer from heat stress.

In cooler weather, such as during fall, mowing at the proper height prepares your lawn for winter dormancy. As the grass stops growing toward the end of the season, your final mow should be slightly lower than usual to prevent matting under fallen leaves or snow in regions where it occurs. However, avoid mowing too short, even for the last mow, as it can leave your lawn vulnerable to damage.

What Happens if You Mow Too Low?

Mowing too low, often called scalping, can lead to several issues for your lawn. When the grass blade is cut too short, it reduces the plant’s ability to photosynthesize, slowing down growth and weakening the grass. Additionally, a scalped lawn is more susceptible to weed growth, as the exposed soil allows unwanted plants to take root.

Shorter grass is also less effective at shading the soil, leading to increased evaporation and dryness. This stresses the grass and forces it to spend more energy on surviving rather than developing healthy roots. Frequent mowing with dull blades can exacerbate the problem, tearing rather than cutting the grass cleanly and making it more prone to disease.

Cutting grass too short also limits its ability to recover from foot traffic, pests, or environmental stress. In worse situations, excessively low mowing can damage the crown of the grass, resulting in thin, bare patches across your lawn.

READ: Avoid These 9 Common Mistakes When Mowing Your Lawn

Best Mowing Tips for New Grass Plugs

If you’ve recently installed grass plugs, understanding the proper mowing technique is crucial for their successful establishment. Grass plugs are small sections of mature grass planted in bare or damaged areas to fill your lawn. They are particularly useful for homeowners looking to establish a healthy lawn faster than reseeding and without the need for full sod installation.

Patience is key when mowing new grass plugs for the first time. It's best to wait until the plugs have fully rooted before mowing, which usually takes around 3 to 4 weeks, depending on the grass type and environmental conditions. Mowing too soon can uproot the plugs and hinder their growth.

Once the plugs are established, follow the same mowing guidelines as you would for an established lawn. Mow at the proper height based on your grass type, and continue to follow the one-third rule. Additionally, ensure your lawn mower has sharp blades to avoid damaging the young grass. Leaving clippings on the lawn, called grasscycling, can help return essential nutrients to the soil, further supporting new grass growth.

Final Thoughts

Mowing height is essential for maintaining a healthy, vibrant lawn. Adjusting your mower height to suit the grass type and season can significantly improve the appearance and resilience of your lawn. Avoiding mowing too low and adhering to best practices—like following the one-third rule—will help you grow a strong and drought-resistant lawn.

Proper mowing timing and techniques are equally crucial to ensuring a healthy establishment when installing new grass plugs. With these mowing tips, you can look forward to enjoying a lush, healthy lawn, ensuring that the grass is greener on your side of the fence.