Burnt grass is unsightly and a symptom of underlying problems caused by poor lawn care practices and unfavorable weather conditions. Burnt grass turns a lawn that was once green into a brown expanse of dry leaf blades. Reviving the burnt grass starts by identifying the causes, knowing the signs, and applying the right care tips.
Deep watering (an inch of water per day), controlling weeds, and fertilizing with N.P.K fertilizers will revive burnt grass. Monitor the new growth and mow the burnt ends. For bare parts, reseed the lawn and irrigate (5-6 inches for 3-5 weeks).
Can burnt lawn revive and come back?
A burnt lawn due to weather changes can recover over time. However, badly heat-burnt grass may die, creating bare spots in your lawn. Burnt grass may recover depending on:
- How long the grass has been dead (Grass that’s been dead for more than five weeks might not recover). Reseeding is the only choice you have.
- Which factor(s) caused the death of the grass like weather changes, excess nitrogen, animal urine, a fire, and heat.
Applying proper lawn care techniques can prevent weeds from occupying the space left by dead grass. The following care tips will help your dead grass (between 3-5 weeks):
Re-hydrate your lawn
Burnt grass due to dehydration can be revived through deep watering. Start by plucking one grass to examine its roots. Are they dry and brittle? If so, then you need to give it water. Keeping the grassroots alive requires you to give it about 1/3 inch of water once after every three weeks.
Grass will tolerate up to three weeks without water. Longer than that, it will turn yellow then brown. Upon watering, its roots will draw in the water and you should see its blades turning green again.
Flush out the fertilizer with water
If you see streaks of solid brown grass spread all over your lawn, it means your grass is burning up. The excess Nitrogen due to over-fertilization prevents the grass from absorbing water and other micro-nutrients it needs for growth. Grass only needs Nitrogen, Phosphorus, and Potassium in ratios of 3:1:2 or 4:1:2.
Deep watering (5-6 inches into the soil) can flush out excessive fertilizer every day until it turns green again. Healthy grass only requires water at least 1-inch per week. Use a gardening hose to ensure the water penetrates deep into the soil.
Clean out urine using water
Does dog urine kill grass? Urine contains ammonia, uric acid, bacteria, and excess nitrogen which are harmful to grass. To determine if animal urine caused the grass burn, pluck out the roots of the grass. Apart from the pungent smell, you will notice some yellow-green stains on the grass surface. If the roots appear rotten, the urine is the primary cause.
If the grass blades are brown but the roots are moist and healthy, it means damage only occurred at the upper layer. Treating burnt grass for animal urine works the same way as flushing out excess fertilizer from the soil. If your lawn isn’t too big, use a sprinkler for deep watering. A bigger lawn with burnt grass may benefit from deep watering using a garden hose. However, as long as your pet keeps urinating on your lawn, the burns will persist.
But, does human urine kill grass? Make sure you train your furry friend to pee in specific places away from the grass. Alternatively, get a litter box and empty the urine and fecal contents regularly as a grass burn preventative strategy.
Water your heat-burnt lawn
Grass growing in a drought-based region may burn due to excessive heat. It gets daunting to determine whether your burnt lawn is due to heat or over-fertilization. Still, an inch of deep watering is one of the best remedies for helping your grass regain its greenness.
Other remedies for treating heat-burns include:
- Postpone mowing until the grass overcomes the dormant stage
Some grass species go dormant in winter or summer, making them turn brown and appear burnt. During this period, grass grows slowly and is very vulnerable to the stress that comes with seasonal changes. Mowing grass at this stage makes it vulnerable to more damage.
- Water your lawn in the morning
Grass loses water to evaporation after morning hours (noon to 4 pm) due to the sun’s scorching heat. Watering it in the afternoon isn’t advisable due to the high evaporation rate. Plan the watering for morning hours when the temperatures are low and fresh, allowing grass to absorb the water.
- Watergrass deeply (5-6 inches)
Shallow watering makes grassroots move closer to the soil surface. This increases its susceptibility to heat damage. Make sure you use a sprinkler or garden hose that can deliver water deeply (5-6 inches) into the soil. Provided the roots absorb water after a heat burn, they will recover.
Treat grass burnt from a fire using a compost heap
In a case of a fire, only the grass blades and stems growing on the top layer of soil will suffer, but the roots will survive. Grass burnt in a fire can recover depending on:
- The grass type: Perennials will bounce back, while annual grass might not grow back because they’ve completed their growth cycle.
- How intensely hot the fire was to cause significant damage.
To treat grass burns due to a fire, rake out the burnt grass to expose the soil. Next, reseed the lawn and apply deep watering (5-6 inches of daily watering for the first three to five weeks). Add compost heap to provide ideal nitrogen content (4 pounds per 1,000 square feet) to your new grass.
Use eco-friendly methods to control weeds instead of herbicides
It’s not advisable to use herbicides when your grass suffers heat damage and prolonged periods of drought. Instead, go for Eco-conscious methods like hand pulling, corn gluten meal application, and the milling process. Should you decide to use herbicides, AVOID doing the following:
- Leaving the weed-infested spot dry after the application for more than three weeks. The grass will eventually die from dehydration.
- Mowing the grass before the three-week recovery period from weeds. The mowed grass might not produce enough energy to recover from burns.
- Adding synthetic-based fertilizer with high nitrogen potency. Grass recovering from weed infestation doesn’t need too much nitrogen as it prolongs the burning side effects.
Signs of burnt grass
Some grass species that prefer warm weather, may turn brown in winter. Cool-season grasses, on the other hand, may also turn brown in summer. Understanding the growing conditions that your grass needs will help you determine if the burn is weather-related or due to any other cause.
Signs of burnt grass include:
1. Leaf blade tips turn brown
The grass may turn brown from the tips to the stem due to excess nitrogen or heat.
2. Brown spots on leaf blades
The leaf blades will have small straw-colored spots, measuring around 6-10 inches in diameter. Factors that can lead to the brown spots in leaf blades include:
- Animal (dog) urine
- Soil acidity. To test for acidity, use a soil test kit under the brown spots.
- Irrigation problem. Soil that’s dry within the top 3 inches indicates a sign of under-watering.
- Herbicide burn: Check for brown patches with grass blades that are white-tipped around where the herbicide application took place. Probably, the herbicide was improperly applied and spread to other plants.
3. Big patches of dead or dormant grass;
A sign of insect or disease infestation.
4. The entire lawn turns brown and shows signs of wilting.
Cool-season grasses go dormant in summer, causing them to turn brown.
If you notice that the burns are weather-related, there is no need to worry. Your grass has gone dormant and will bounce back once (after three weeks past the dormancy period) the recommended growing conditions get restored. But if it’s due to fertilizer burn, urine, under-watering, or a fire, it’s time to apply proper lawn care solutions to revive it.
What burns grass?
The grass may burn due to the following reasons:
Fertilizer burn (Excessive Nitrogen)
A 1,000 sq feet lawn needs 4 pounds of Nitrogen per year to promote its growth by encouraging the production of chlorophyll for photosynthesis. Applying more than 4 pounds can cause burns in the grass blades and roots. You’ll know you’ve applied excess nitrogen if:
- You use synthetic fertilizer, destroying microbial activity in the soil.
- Apply it unevenly, causing a once green lawn to turn yellow-brown.
To determine if the burnt grass is still alive, try plucking out a few strands of grass. If they don’t pull out easily, they can benefit from deep watering (6-7 inches). Make sure to water the affected patches, preferably 1-inch into the soil. Repeat 3-4 times as the soil dries up. The water will drive the excess nitrogen deeper into the soil. To prevent fertilizer burn, apply a compost heap as it doesn’t contain a lot of nitrogen.
High Nitrogen content in animal urine, especially in dogs is toxic to grass. You’ll see straw-colored spots or patches on areas where your dog frequently urinates. If training your dog to urinate in other places doesn’t seem practical, replace the grass with fescues or perennial ryegrass as they’re urine-tolerant.
Heat burns due to high temperatures
Grass species are divided into two groups: warm and cool-season grasses. For the latter, prolonged exposure to high soil temperatures (more than 65 degrees Fahrenheit) will cause dormancy and cause them to turn brown. The former prefer soil temperatures of 65-70 degrees Fahrenheit but that doesn’t mean it will withstand temperatures higher than that range.
Mowing dormant grass can also lead to browning, so it’s best to avoid it at this stage. Reviving heat burn starts by irrigating the grass deeply (5-6 inches) into the soil. This encourages the roots to grow deeper into the soil, escaping future heat burns. Make sure you water it in the early morning hours (between 6 am and 8 am) when the transpiration rate is low.
Improper herbicide application
Herbicides, when used incorrectly, can cause injury to your grass. For example, herbicide designed for cool-season grass instead of warm-season grass will eventually coat the grass surface. With time, the herbicide coating on the grass blades turns toxic, preventing the grass’ air and water absorption ability.
Fires, whether by default or design, can cause browning or even blacken the grass. It could be that you were hosting a barbecue and hot charcoal fell on it by mistake. Perhaps someone forgot to put out their cigarette before throwing it on dormant grass.
Fire may burn the leaf blades but as long as it doesn’t spread to the roots, the grass will survive. Especially if it belongs to the native prairie varieties. For example, cool-season grasses go dormant and brown and their roots go deep away from the freezing topsoil temperatures. Even in a fire, it’s only the turf blades that will suffer. Once they exit the dormancy stage, the roots will encourage the sprouting of new blades.
When and how fast your grass recovers from scorching depends on what caused it in the first place. With the right lawn treatment plan, your grass can regain its greenness again. First, figure out if excessive nitrogen, heat, a fire, or animal urine was the cause.
When treating your burnt lawn, consider the type of grass, local weather patterns, and the cause of the burn. You’ll know you applied the right care tips if your grass turns green from brown after about three to four weeks.
Key takeaways for preventing lawn burns
- Avoid applying too much nitrogen to your lawn
- Designate a different spot for your pet to urinate on, not on grass.
- Water your lawn daily during drought periods (1-inch of watering)
- Use herbicides as a last resort to weed control
- Avoid mowing dormant grass even if it looks burnt
- Prevent fires by designating a special place for recreational activities that may lead to fires
- Test the soil for hyper-acidity. Once it tests positive for it, apply weak alkaline solutions like bicarbonate of soda or lime
- Choose a grass type that can bounce back quickly (regain its greenness) if burns occur.
- Apply good lawn care management practices like applying compost instead of fertilizer and 1-inch watering every three weeks.
Source and References
- University of Illinois Extension: Watering Guidelines for Home Lawns