Grass burn refers to brown or dead patches that appear on a lawn, contrasting sharply with healthy green turf. This common issue signifies that grass plants are under severe stress or have been damaged, leading to discoloration and, in some cases, plant death.
Common Causes of Grass Burn
Several factors can lead to grass burn, often resulting in similar brown patches but requiring different approaches for recovery.
A frequent cause is the over-application of fertilizer, where excess mineral salts draw water away from the grass roots, causing desiccation. This can manifest as yellow or brown streaks, particularly if granular fertilizer application overlaps or is spilled. Quick-release fertilizers carry a higher risk due to their immediate nutrient availability and salt content.
Pet urine is another common culprit, with the high nitrogen concentration in dog urine burning grass, leading to distinct brown spots. While small amounts of nitrogen can fertilize grass, a concentrated dose acts like an overdose, causing damage. Female dogs often cause more noticeable damage as they tend to urinate in a single, concentrated spot, unlike males who may spray over a larger area.
Chemical spills, such as gasoline, oil, or herbicides, can also severely burn grass by contaminating the soil and directly harming plant tissues. These incidents often result in sharply defined dead areas.
Finally, severe drought and heat stress can cause grass to turn brown as it struggles to retain moisture, leading to dormancy or death. This is particularly common in summer months when temperatures are high and rainfall is scarce.
Immediate Steps to Address Grass Burn
Addressing grass burn promptly can mitigate damage and improve recovery prospects.
If the burn is from fertilizer over-application or a chemical spill, immediately flush the affected area with water. This dilutes the concentration of salts or chemicals in the soil, preventing further absorption by grass roots. For fertilizer burn, soak the area deeply for at least a week, providing about one inch of water daily, to flush out excess salts.
For pet urine spots, dilute the area with water immediately after the dog urinates. Simply pouring a generous amount of water over the spot helps spread the nitrogen and reduce its concentration.
For burns caused by drought or heat stress, deep and consistent watering in the early morning is important to rehydrate the grass and soil. This allows the grass to absorb moisture before the heat of the day causes rapid evaporation.
If a chemical spill involves gasoline or oil, contain the spill quickly before removing the contaminated material and flushing the area with water. For severe chemical burns, removing the dead turf and the top few inches of contaminated soil may be necessary before drenching the area to dissipate any remaining chemicals.
Restoring Burned Areas
Once the immediate cause of grass burn has been addressed, restoring the affected areas can begin.
First, remove any dead grass and debris from the burned patches to create a clean surface for new growth. This can be done by raking or using a stiff brush to clear away dead blades and thatch. Assess the damage; yellowed grass might recover with proper care, while crunchy, brown grass may indicate complete death, requiring replanting.
Prepare the soil in the damaged areas for successful restoration. If the soil is compacted, aerating the spots with a garden fork can improve air circulation and water penetration. Incorporating a thin layer of nutrient-rich topsoil or compost into the prepared patches can enhance soil structure and provide a better environment for new grass roots.
Re-establishing grass can be achieved through several methods, depending on the size and severity of the burned area. For smaller patches, overseeding is a common approach where new grass seed is spread over the prepared soil. For larger, completely dead areas, patching with sod offers a quicker solution, providing an instant lawn that blends with existing turf. Alternatively, plugging, which involves transplanting small plugs of healthy grass into the damaged area, can be effective for certain grass types, particularly warm-season varieties.
Preventing Recurrence
Preventing grass burn involves adopting consistent lawn care practices.
Proper fertilization is a preventative measure; always follow manufacturer recommendations for application rates and use a spreader for even distribution. Opting for slow-release fertilizers can reduce the risk of burn, as they provide nutrients gradually over time, unlike quick-release types that can overwhelm the grass with salts. Fertilize a moist lawn and water thoroughly after application to help nutrients soak into the soil and prevent fertilizer from sticking to grass blades.
Appropriate watering practices are also important, especially during hot and dry periods. Deep and infrequent watering, aiming to soak the soil to a depth of 6-8 inches, encourages deeper root growth, making the grass more resilient to heat and drought. Watering in the early morning minimizes evaporation and allows grass blades to dry before nightfall, which can prevent fungal diseases. Avoid watering during the hottest part of the day, as much of the water will evaporate before reaching the roots.
Managing pet waste is another preventative step. Encourage pets to use designated areas for urination. Increasing a dog’s water intake can also help dilute the nitrogen concentration in their urine, making it less harmful to grass.
For chemical handling, refuel lawn equipment on paved surfaces and use funnels to prevent spills. Store chemicals securely and apply them on calm, non-windy days to reduce the risk of accidental contact with the lawn.