Brown grass underneath green grass 5 common causes explained

In the quest for a lush, vibrant lawn, homeowners often encounter a perplexing issue: grass that appears healthy and green on top yet reveals a concerning brown underlayer upon closer inspection. This phenomenon can be disheartening, detracting from the beauty and health of your outdoor space. However, understanding the root causes of this condition is the first step toward remediation. This article will delve into five common causes of grass turning brown underneath a green surface.

Thatch Buildup

Thatch refers to the layer of dead grass, roots, and leaves that accumulate between the soil surface and the live grass. Although a thin layer of thatch can be beneficial as it acts as a natural mulch to retain soil moisture, an excessive buildup can cause problems. It can block water, nutrients, and air from reaching the soil, leaving stressed and brown grass underneath the green blades.

Solutions: Regular dethatching is essential to combat thatch buildup. A manual thatch rake might suffice for small lawns, but for larger areas, consider renting a mechanical dethatcher. The best times for dethatching are during the lawn’s peak growth periods, typically in early spring or early fall, which allows the grass to recover more quickly​​​​.

Credit: thelawnforum.com

Improper Watering (Underwatering and Overwatering)

Proper watering is critical for maintaining a healthy lawn. Underwatering can lead to drought stress, causing the grass to conserve water and nutrients by turning brown at the base. Conversely, overwatering can drown the roots, depriving them of oxygen and leading to similar stress symptoms.

Solutions: Implementing an efficient watering schedule that promotes deep-root growth is critical. Watering deeply and infrequently encourages roots to grow deeper into the soil, seeking moisture and nutrients. This method helps establish a more drought-resistant lawn. The exact watering needs vary based on climate, soil type, and grass species, but a general rule is to provide 1 to 1.5 inches of water per week​​​​​​.

Nutrient Imbalance and Soil Fertility Issues

Grass requires a balanced diet of nutrients like nitrogen, phosphorus, and potassium, which can weaken the lawn if it’s starved, leading to browning at the base. On the other hand, too much fertilizer can cause nutrient burn, stressing the grass and causing a similar browning effect.

Solutions: Conducting a soil test is the first step in identifying nutrient deficiencies or pH imbalances. Based on the test results, apply the appropriate type and amount of fertilizer to correct the imbalance. A balanced, slow-release fertilizer can provide a steady supply of nutrients without burning the plants. 

Soil Compaction

Soil compaction restricts the permeation of the soil of air, water, and nutrients in the soil, making it difficult for grassroots to grow and access the needed resources. This can lead to a stressed lawn with brown grass underneath the green surface.

Solutions: Aerating the lawn can relieve soil compaction by removing small plugs of soil from the lawn to improve air and water penetration. Aerating is most effective during the lawn’s growing season, allowing the grass to recover and fill any open spaces left by the aeration process. For best results, use a core aerator, which removes small cores of soil rather than simply poking holes in the ground​​.

Seasonal Dormancy and Environmental Stress

Grass can enter a dormant state in response to environmental stress, such as extreme heat or cold. During this time, the grass conserves energy and resources, leading to browning at the base. This dormancy is a natural survival mechanism and not necessarily indicative of a dead lawn.

Solutions: Patience is essential during periods of dormancy. Continue to provide basic lawn care, such as proper watering and avoiding foot traffic in stressed areas. Once favorable conditions return, the lawn should begin to green up again. Implementing lawn care practices that enhance the lawn’s resilience to stress is also beneficial, such as proper fertilization, mowing at the correct height, and overseeding with drought-resistant grass varieties​​.

Can brown grass turn green again?

Yes, brown grass can turn green again under the right conditions and with proper care. The key to reviving brown grass lies in distinguishing between dead grass and dormant grass. Dormancy is where grass conserves energy and resources during unfavorable conditions, such as extreme temperatures or lack of water, leading to a brown appearance. However, this doesn’t mean the grass is dead; it’s essentially in hibernation mode and can green up again when conditions improve​​.

To revive brown grass and turn it green again, several steps are recommended:

1. Proper Watering: Deep and infrequent watering is more beneficial than shallow watering. Aim for about an inch of water per week, ideally in the early morning, to minimize evaporation and allow water to penetrate deeply into the soil​​.
2. Fertilizing and Aerating: Providing your lawn with the necessary nutrients and aerating the soil can help improve its health. Aeration allows air, water, and necessary nutrients to reach the grassroots more effectively​​.
3. Mowing at the Correct Height: Keeping your lawn at an optimal height of 2-3 inches can promote better health and prevent stress. Avoid cutting grass too short, as this can make it more susceptible to diseases​​.
4. Addressing the Root Cause of Brown Grass: It is crucial to understand why your grass turned brown in the first place. This could be due to a lack of water, nutrients, over-fertilization, diseases, or overwatering. Addressing the specific issue, whether adjusting your watering schedule, using the right type and amount of fertilizer, or treating any diseases, is essential for the lawn’s recovery​​​​.
5. Choosing the Right Grass Type: Selecting a grass type well-suited to your climate and soil conditions can also help prevent issues. Some grass types are drought-resistant, while others may thrive better in cooler or wetter environments​​.