So you’ve got a brown grass problem in the middle of your beautiful, lush lawn, and you’re pulling your hair out. Is your lawn dead? Is it beyond repair? Don’t worry, there’s a good chance you can save it.
To get your burnt grass green again, figure out what caused the burn. Fertilizer/urine burns can be treated with shallow waterings to remove the excess nitrogen and salt. Heat and fire burns require regular deep waterings. If the grass is completely dead, then you need to reseed.
What Does Burnt Grass Look Like?
Leaf scorch or leaf burn is when leaves (like grass blades) develop brown spots on their tips, looking like the grassblade was burned with fire. Burnt grass can also refer to grass that has been burned by fire.
However, sometimes people use “burnt grass” to refer to spots that have wholly turned brown, which could be an advanced stage of leaf burn or caused by something else.
Finding the cause of burnt or brown grass requires a bit of detective work. If you have:
- Brown-tipped grass is definitely leaf burn, either from excess nitrogen or heat.
- Brown spots:
- Small (around 6-10”) straw-coloured patches surrounded by green turf is generally from dog urine.
- The soil’s pH may be too high/acidic. Use a home soil test kit to determine the pH of the soil under the brown spots. Excess nitrogen can raise the pH level.
- One large brown spot could indicate a problem with one sprinkler. Check if the soil is dry within the top 3” by sticking in a stick or screwdriver and seeing if the end is wet.
- Brown patches with white-tipped grass blades around a place where herbicide was used are generally chemical burn, where herbicide was applied improperly and was spread to other plants.
- Larger patches of dead or dormant grass may be due to insects, disease, or buried rocks or debris.
- Strips or patchy brown grass throughout the lawn may be caused by over-fertilizing with nitrogen or not applying the fertilizer evenly. Dark green grass has had fertilizer applied properly. Pale green grass hasn’t received enough fertilizer. Yellow grass could be either too little fertilizer or too much nitrogen, restricting the grass’ ability to absorb other nutrients. Brown grass has been over-fertilized.
- The whole lawn is turning brown or wilting. The grass isn’t “burnt”, but either it’s going dormant during the summer heat (cool-season grass) or it needs a deep watering.
The University of Maryland Extension has an excellent pictorial guide to help you match your brown lawn problem with causes and solutions.
Will Burnt Grass Come Back to Life?
Whether burnt grass can be brought back to life depends on how far gone it is. With excessive nitrogen, grass can be saved if it’s:
- Grass blades are dark green and growing way too fast (early-stage)
- “Burns” on the grass tips (middle-stage)
- Turning yellow or brown (late-stage)
Also, take a look at the roots in different sections of the burned spots. If the roots look healthy, that’s good news! As long as the roots survive, grass will regrow.
If the roots look “burned”, are black, or have the consistency of mush, then it’s often too late.
The earlier you catch burnt grass, the easier and more likely it is that you can save the grass.
However, once the grass dies, it’s beyond repair. To see if your grass is dead, grab a handful of the brown grass and pull. If it comes out with no resistance, then it’s dead.
If there is some resistance, it may be dormant (like in the middle of summer) or just close to dead. (Dormant grass only needs for the summer heat to pass and to receive more frequent deep waterings to revive.)
You should still follow the watering instructions for fertilizer burn even if the grass has died as you still need to flush the excess nitrogen out. Otherwise, if you try to reseed or resod, you’ll have the same problem.
How Long does it Take Burnt Grass to Grow Back?
How long it takes for burnt grass to recover depends on their stage of burn. If caught early, burnt grass can revive by the end of the week. Later stages may require weeks of care to recover.
The burns won’t disappear (that foliage is forever damaged) but the great thing about grass is that it grows. If you can save the grass, you can mow the lawn, remove the foliage with the burns, and it’ll be as if it never happened.
Reasons Why Grass Burns and How to Get Back to Green
Fertilizer Burn (Too Much Nitrogen)
Nitrogen turns grass that beautiful green, but too much nitrogen can cause serious damage. Fertilizer burn is when you apply too much synthetic fertilizer to your grass, either by applying more than the fertilizer calls for or by applying it unevenly. If applied unevenly, you’ll see stripes of green, brown, and even yellow grass.
If the burned grass is still alive, then (as soon as possible) start to water the affected patches in quick bursts, only wetting down 1” into the soil. Repeat 3 to 4 times as the soil dries. This will carry the excess nitrogen deeper into the soil.
But if you water too much, then you’ll create a run-off, where the nitrogen is carried into the groundwater or into the sewers, where synthetic nitrogen can do a lot of damage.
To prevent fertilizer burn, use compost! Compost has less nitrogen overall (and generally no synthetic nitrogen, which can cause a lot of problems for your lawn) making fertilizer burn impossible, but still enough nitrogen to feed your grass.
Grass doesn’t need a ton of nitrogen to begin with. According to the University of Illinois Extension Office, grass only needs an NPK of 3:1:2 or 4:1:2.
Get started with compost this spring with our handy guide to add organic matter to your lawn.
Animal urine is high in nitrogen, so when dogs urinate on grass, the grass can turn straw-coloured.
Treat animal urine like you would fertilizer burn, hosing off the patch in quick waterings to carry the excess nitrogen deeper into the soil. You can also use rainwater or wastewater to quickly water the area after your dog urinates.
If you have a dog or frequently have neighbourhood dogs urinating on your lawn, then:
- Replace the grass with a urine-tolerant grass like fescue or perennial ryegrass, a tall meadow, or white clover. As a bonus, these replacements need less water and less or no fertilizer.
- If you do fertilize, use either compost (which has a ton of other benefits) or a synthetic fertiliser with lower amounts of nitrogen.
- Replace high-trafficked areas with gravel, mulch, or astroturf.
- Train your dog to only pee in specific places.
Also, don’t use “grass-saving” supplements on your dog. They don’t work, because they’re either altering the pH rather than the amount of nitrogen or causing your dog to drink more water to dilute their urine, and you will harm your dog. Your dog is more important than a piece of lawn.
Heat burn happens when the lawn is stressed during high temperatures, like mowing in the hottest part of the day. It can be misidentified as fertilizer burn, especially if you used fertilizer recently, but requires a much deeper watering to treat. When in doubt, take a look at recent temperatures.
To avoid heat burn:
- Avoid mowing dormant grass (your entire lawn will turn brown).
- Mow either between 8 to 10 AM or 4 to 6 PM to avoid the heat of the day.
- Keep your mower blades sharp so they cut the grass cleanly instead of tearing, which stresses the grass out even more.
- If you irrigate, water to the top 4 to 6” of soil. Avoid watering shallowly. Deep waterings encourage the roots to grow deep within the soil, where they’re protected from the heat. Shallow waterings encourage roots to grow along the top, where they’re more likely to get scorched and die.
To treat heat burn:
- Avoid mowing your grass as long as possible.
- DO NOT FERTILIZE OR APPLY PESTICIDES OR HERBICIDES. Fertilizing a heat-burnt lawn won’t make it greener, it’ll just add more stress on the grass. Pesticides and herbicides will also hurt your lawn.
- Water your lawn early in the morning when it’s still cool out, which will help your damaged grass to absorb the water, and water as deep as 5 to 6”, so all the roots have access.
- Give your lawn time. As long as the roots are in a healthy state, grass will recover. Let the heat pass. Let the grass heal itself.
Herbicide injury appears as brown patches or the grass tips turning white.
This could affect your grass from two causes:
- Using a herbicide not approved for your turf grass on something else, but due to rain or windy conditions, the herbicide now coats your grass.
- Using a herbicide that is supposed to be okay with your turf grass species, but other stressors (like heat, sandy soil, and lack of water) pile on. Even herbicides that are said to be okay to use on specific turf grasses do still hurt the grass. Just usually not enough to kill it.
The best way to avoid this is to not use herbicides whenever possible. There’s a ton of easy ways to help you deal with weeds.
The second best way is to use the herbicide as labelled, which will help avoid cause #1, and to avoid using herbicide when your grass is stressed from high temperatures and lack of rain.
- Keep the affected spot moist for up to 3 weeks after the herbicide application to help the grass keep hydrated.
- Avoid mowing the grass for 3 weeks, and when you do mow, keep the grass as high as possible so that the grass can continue to produce enough energy to recover.
- Fertilize with a small amount of nitrogen (compost works great).
- Don’t apply any more herbicides while your grass is recovering.
The most literal meaning of “burnt grass”, your grass has caught on fire. This could be because a hot charcoal fell on it, someone threw a lit cigarette on dormant grass, a fire pit was on top of the lawn, or from a wildfire.
Don’t burn your lawn on purpose, as it can:
- Be extremely dangerous if the fire gets out of control, (as gardening expert Walter Reeves so eloquently put it, “Explaining to your spouse or neighbor or insurance agent how you “….just didn’t think it would go so fast……” is not a conversation you would like to experience.”)
- Be illegal where you live,
- Create smoke that causes health problems (especially if you live in an area where open fires cause whole blocks to reek of smoke. If you or your neighbours have respiratory problems, then this is especially bad),
- Destroy animal and insect habitats, and
- Depending on the grass species, you could kill the lawn,
- And you’ll have a big, ugly charred lawn. (And no, it won’t grow back greener.)
So what happens if your grass does burn by accident? Is it dead?
The good news is that many grass species (especially native prairie varieties) are well-suited to surviving fires. All they need to survive is healthy roots. This is why cool-season grasses will go brown and dormant in mid-summer — they don’t expend resources on grass blades and instead focus on surviving to cooler weather and more rain.
Fire generally only affects the top layer of soil, so as long as your grass has grown deep roots, your lawn will bounce back. (You will have to put up with a burn spot until it does.) Just keep supporting your grass with deep waterings. (A light fertilizer like compost can also help.)
However, annual grasses and shallow-rooted grasses probably won’t survive, so you will need to reseed.
Brown and burnt grass does not mean game over. Identify the problem, check the roots, and apply a little TLC with the right kind of watering.