What is Fertilizer Burn? 

grass scorched by fertilizer

Striped, uniform lawns are a sight to behold, as baseball fans will attest. However, if those stripes are irregular or discolored, you may have fertilizer burn, a sign that your grass has been over-fertilized.

Though unsightly, fertilizer burn is a common lawn care mistake that can be fixed with a little care. In this article, we explain what fertilizer burn is, provide prevention tips, and describe what you can do if it’s happening to your lawn.

What is fertilizer burn?

Apart from providing your grass with necessary nutrients such as nitrogen, potassium, and phosphorus (NPK), fertilizer also increases your lawn’s resistance to diseases, pests, and foot traffic damage. With a robust lawn at your disposal, you’ll breathe cleaner air and enjoy less stifling temperatures in summer.

If you’re a do-it-yourselfer, you may think that the more fertilizer you apply, the better your lawn will look. After all, fertilizer is food for your grass, so how much harm can it really do? The answer is plenty. 

Fertilizers contain salts that accelerate nutrient release for grass intake. When you apply too much fertilizer to your lawn, the excess salts seep into the soil, surround the root system, and prevent proper water absorption. Once your grass is affected at the root level, it loses its health, vitality, and vibrant color, leaving you with dead brown patches.

In essence, excess fertilizer can:

  • Kill your grass
  • Contaminate nearby waterways
  • Harm wildlife
  • Disrupt soil microbial growth

Note: If you’ve been skipping regular lawn care, your lawn may already be in bad shape, making it more susceptible to fertilizer burn. Using fertilizer as a band-aid to cover bigger lawn issues will only make things worse and leave you frustrated. Check out our guide to lawn fertilization for more information on keeping your lawn looking fabulous.

How to identify fertilizer burn

fertilizer burn on grass leaves
Scot Nelson | Flickr | CC0 1.0

Watch out for these signs of fertilizer burn in your lawn:

  • Grass blade discoloration streaks
  • A lack of new grass growth where there should be
  • Patches of yellow or brown grass resembling scorch marks. The grass will typically be crispy or crusty to the touch.
  • Checkerboard-like shapes, with burned areas in the middle of each square. This is typically the result of fertilizer overlap.

How to fix fertilizer burn

Fertilizer burn doesn’t necessarily mean a death sentence for your lawn. Depending on the level of damage, certain affected areas can be brought back to life with the proper care. 

Here’s what you need to do to fix fertilizer burn.

Thoroughly inspect your lawn

Inspect every inch of your lawn and determine if the entire lawn is affected or only select areas. Check the roots for damage by pulling a section out of the ground and examining its condition. Healthy roots will look white, long, and dense, whereas damaged roots will have a grayish, brittle appearance.

Consider all the possible reasons your lawn could look unhealthy, and ensure you’re targeting the correct problem. Yellow or brown patches can also mean a lack of moisture, lawn diseases, or signs of your pet urinating on your lawn. However, if you’ve recently fertilized your lawn, and it’s looking stripey in certain areas, chances are you’re dealing with fertilizer burn. 

Remove damaged grass and leftover fertilizer

If fertilizer burn is indeed affecting your lawn, pull out as much of the damaged grass as possible. Use a rake in stubborn areas and a broom to sweep it all up. Next, look for leftover fertilizer sitting on your grass, removing whatever you find to minimize any other damage. The longer you leave it on your grass, the more damage will occur.

Water your lawn

Overfertilizing your lawn is like eating too many very salty french fries. To properly flush the fertilizer salts out of the soil, the solution is simple: provide large amounts of water.

Hydrate your lawn every day for a week or two, setting your sprinkler to provide about 1 inch of water a day to affected areas. This should be enough water to flush out the salt buildup and allow your grass to recover. 

It’s best to water your lawn in the morning, before 10 a.m., giving it enough time to absorb the moisture throughout the day. Otherwise, you may be adding fungi problems to your fertilizer burn.

Reseed, if needed

Check your lawn for new growth. If there is no new grass growth, you may have to start from scratch. Dig up the dead grass from the roots, reseed, and wait for fresh grass to appear. Apply fertilizer about 4 to 5 weeks after new grass growth, following the instructions exactly to avoid a repeat fertilizer burn problem.

How to prevent fertilizer burn

Preventing fertilizer burn is easier than you think. Follow these tips to keep your lawn looking fresh year-round:

  1. Don’t apply fertilizer when your lawn is dormant or under drought or heat stress. Wait for cooler weather and some rainfall to fertilize moist soil. Follow up by watering the lawn to distribute the fertilizer evenly.
  2. Don’t apply fertilizer to extremely wet grass. The water will cause the fertilizer to stick to the grass blades and burn your lawn. Not to mention that the distribution of the nutrients will be uneven, and you may even experience runoff.
  3. Choose a slow-release fertilizer. This type of fertilizer guarantees long-term lawn health without any toxicity. It also contains a lower concentration of salts that are released gradually into the soil, preventing fertilizer burn. For help selecting the right fertilizer, give this fertilizer selection a read-through.
  4. Follow the application instructions. This will ensure fewer mistakes and subsequent consequences for your lawn.
  5. Use a quality spreader you know will apply the product according to your lawn’s needs and the application instructions on the package. If unsure, give it a test run beforehand and make any necessary adjustments.
  6. Try to avoid fertilizer overlap; cover each section thoroughly, maintaining a steady and careful pace. After application, irrigate the granules to push them into the ground and off the grass blades.
  7. Fertilize according to your soil’s needs. If you haven’t performed a soil test in some time, now may be a good time. You’ll have a much clearer picture of your soil’s condition and any existing deficiencies or pH problems.

FAQ about fertilizer burn

Are there any other reasons I may have brown spots on my lawn?

If you haven’t fertilized recently, here are a few other reasons your lawn may have brown spots:

  • Fungi
  • Scalping
  • Dormancy
  • Diseases
  • Dog pee spots
  • Chemical or gasoline spills
  • Insects, such as grubs or chinch bugs

Can organic fertilizers cause fertilizer burn?

Yes, if you apply more than the label recommends. However, most organic fertilizers are naturally slow-release. Whether organic or synthetic, slow-release fertilizers are much less likely to cause fertilizer burn than fast-release fertilizers – especially if applied according to the label.

What’s the difference between synthetic and organic fertilizers?

The key differences between synthetic and organic fertilizers are as follows:

FactorsOrganic Synthetic
Advantages✔ Doesn’t burn lawns
✔ Slow and steady nutrient release
✔ Contains many trace minerals and balanced nutrition for your grass
✔ Improves soil health
✔ More commonly available
✔ Formulas made for exact lawn needs
✔ Acts quickly
✔ Costs less
Disadvantages✘ Less nutrient release in cooler temperatures
✘ Costs more
✘ Dependent on microorganisms in the soil
✘ Shorter lifespan
✘ Can deteriorate soil
✘ Can burn lawn
✘ May cause chemical runoff

Professional help at your fingertips

There’s no reason you should have a less-than-stellar lawn. If your fertilizer applications have failed to yield the desired result, consider reaching out to a local lawn care pro for guidance. They’ll care for your lawn year-round, fertilizing, mowing, and edging to your satisfaction.  

Main Photo Credit: Sten Porse | Wikimedia Commons | CC BY-SA 3.0

Andie Ioó

In my free time, I enjoy traveling with my husband, sports, trying out new recipes, reading, and watching reruns of '90s TV shows. As a way to relax and decompress, I enjoy landscaping around my little yard and DIY home projects.