Over Fertilization and Fertilizer Burns: Causes, Prevention, and Remedies for Your Lawn

By Clyde Atkins |

Over Fertilization and Fertilizer Burns: Causes, Prevention, and Remedies for Your Lawn

Everyone loves a green, lush lawn, right? One way to get that perfect green color is by using fertilizers. But sometimes, using too much or using them the wrong way can cause problems. Let’s dive into these challenges and figure out how to keep our lawns looking their best.

What Causes Fertilizer Burns?

Imagine you’re really thirsty and you drink too much soda too quickly. It doesn’t feel good, right? Grass feels the same when it gets too much fertilizer. Add some hot weather to the mix, and the grass can get “burnt.” This is because some fertilizers have a lot of nitrogen. While grass likes nitrogen, too much without enough water can hurt it.

All fertilizer burns from over-fertilization boil down to one simple thing: too much nitrogen in the soil at a time when the grass is unable to absorb and "eat" it. The grass may be dormant, and therefore not able to use the nitrogen, or it may be dealing with heat stress that prevents it from growth. 

Timing Is Everything: Prevent Burns by Applying During Growth

Think of your lawn like a bear. Yes, a bear! Bears hibernate during the winter, and if you tried to feed them during their deep sleep, they wouldn't be too happy. Similarly, your lawn has times when it's super active and times when it's taking a little nap, or "dormant." One big mistake many people make is feeding their lawns when they're dormant.

For cool-season grasses (common in the northern half of the US), summer is their nap time. If you add fertilizer during these hot months, it's like waking up that sleeping bear. The grass isn't ready to use the nutrients, and this can lead to those dreaded fertilizer burns. Remember: Know your grass type and feed it at the right time. If you have cool-season grass, spring and fall are your best bet for fertilizing. That way, your lawn gets the nutrients when it's ready to grow, and you avoid unnecessary burns.

How Much Fertilizer Is Too Much?

Once upon a time, people believed in a simple rule: give your lawn 1lb of nitrogen for every 1,000 square feet. It sounded easy, but here's a surprise: modern soil science has busted this myth! New research, called MLSN (short for Minimum Levels for Sustainable Nutrition), tells us something different. You might be wondering, "What does this mean for my lawn?" Well, it means you might not need as much fertilizer as you once thought, especially if you're using a really good quality one.

Need help figuring out exactly how much you need? Measure your lawn using our Lawn Size Calculator, and we'll tell you exactly how much to apply with your Magic Lawn Plan

Different Forms of Nitrogen: The Good and The Bad

Did you know there are different kinds of nitrogen in fertilizers? Look for a form of nitrogen called "urea." You'll need less, and it's healthier for your grass. Other forms, like ammonium nitrate, are kind of like junk food for the lawn. They can cause burns if you're not careful. Imagine eating too much spicy food and feeling the burn! Natural sources like urea are like a home-cooked meal for the grass. They’re gentle, effective, and provide the best nutrition without the risk of burning. If you want your lawn to be green, happy, and burn-free, picking a fertilizer with urea is the way to go.

Slow-Release Fertilizers Are Less Likely to Cause Burns

Some fertilizer is adapted to allow for a slow release of nitrogen into the soil. Fast-release fertilizers provide a quicker green up, but can easily burn the grass on hot days. Urea triazone is a common form of urea bonded with another molecule to limit the speed of release. Nitrogen from ammonium is always fast-release. It's like eating too much candy all at once instead of spreading it out over a few days.

Liquid Fertilizers Also Reduce Chance of Burns

Liquid fertilizers provide evenly spread nutrients that quickly reach the roots for better absorption. On the other hand, granular fertilizers sit on the soil longer and do not distribute nutrients as evenly. If applied heavily or not watered in properly, they can hang around too long and create hotspots, leading to burns.

If you're worried about burns, liquid fertilizers might be your best bet. If you go with granular, make sure to water it in thoroughly.

Recognizing the Signs of Over Fertilization and Fertilizer Burns

Burnt grass looks sad. It can turn yellow or even brown in patches. If your lawn looks like it has had a bad sunburn, it might be due to over fertilization. If you fertilized recently, that's another good sign that over fertilization is the culprit. 

Preventing Fertilizer Burns and Over Fertilization

Nobody wants a brown lawn. To prevent these problems:

  1. Use a slow-release, urea-based nitrogen fertilizer like Green Glow (50% slow-release) or All-in-One Grass & Garden (70% slow-release)
  2. Use liquid fertilizers (like the two above) or water your granular fertilizer in after you apply. This is like giving the grass a good drink to help digest the nutrients.
  3. Fertilize at the right time to make sure your grass is growing and able to use the nutrients
  4. Spread the fertilizer evenly. It's like sprinkling sugar on cereal; you don’t want one spot to get all the sugar.
  5. Don’t put too much! Less is often more.

How to Treat and Repair Fertilizer Burns

Oops! Did the grass get burnt? No worries, we can fix it:

  1. Stop adding more nitrogen fertilizer: Give the grass a break from the “food.” Don't apply anything with nitrogen. 
  2. Add natural stuff: Things like seaweed (kelp) or humic acids help the grass use up the extra nitrogen. It’s like giving the grass some healthy veggies after too much candy. We recommend Liquid Lush for nitrogen-free nutrients to beat heat stress and improve nutrient update. 
  3. Water regularly: But don’t drown it. Just enough to help the grass heal.
  4. Overseed: If some areas look super sad, you might need to seed spread new grass seeds there.

Keeping a lawn green and happy is like taking care of a pet. It needs food, water, and love. Just remember not to overfeed it with fertilizer, especially on hot days. And if something goes wrong, now you know how to fix it!

Common Questions

  1. How long does it take for grass to recover from fertilizer burn? Like a sunburn, it might take a few weeks. Just be patient and keep taking care of it.
  2. Can a lawn fully recover from over fertilization? Yes, with the right care and love, it can bounce back!
  3. How often should I fertilize my lawn to avoid burns? It’s best to follow the instructions provided in your Magic Lawn Plan. Depending on where you live, you can apply nitrogen up to 7 times per year.

Feed your lawn some Liquid Lush (nitrogen-free nutrients) to give immediate relief with kelp and humic acids to improve nitrogen absorption and fight heat stress.