What Happens if You Apply Too Much Fertilizer for Grass?

In an attempt to make their lawn healthy and green, many homeowners can easily get carried away by dumping some fertilizer on the soil—and then some more. 

The more fertilizer, the healthier and greener, right?

Wrong.

Yes, You Can Over-Fertilize Your Lawn

While fertilizer is a vital part of lawn maintenance, using too much is the complete opposite. Instead of providing your grass with the essential nutrients to create a greener lawn, applying a little too much lawn fertilizer can dry your grass, which may eventually lead to its demise. It’s as bad as not applying enough, if not worse.

Besides damaging your lawn, excessive fertilization can waste time and money. It also poses environmental risks as nutrient leaching, or the drainage of nutrients from the soil, has the potential to contaminate nearby bodies of water.

What are the Signs of an Over-Fertilized Lawn?

Lawn fertilizers are mainly a balance of essential nutrients—nitrogen, phosphorus, and potassium—that work together to keep your grass green, dense, and resistant to drought, pests, diseases, heavy foot traffic, and stress, among other environmental threats.

However, when applied excessively, the same nutrients intended to promote healthy grass growth can instead turn the grass yellow or brown.

Yellow or Brown Grass Tips: An indication of using too much fertilizer for grass is the yellowing or browning of the tips of the grass blades.

Fertilizer Burn: Fertilizer burn is when excess fertilizers build up on the soil surface. In severe cases, it can scorch your blades, where your grass turns brown and may even be dead.

Stunted Growth: The imbalance of nutrients may lead to toxicity, inhibiting your lawn's ability to absorb nutrition, thus resulting in slow to no plant growth.

Black or Limp Roots: Roots should be reasonably firm. However, excess salts in the root zone can damage them, making them limp, dull, or black.

Even if your lawn doesn't show the usual signs of over-fertilization, the excess nitrogen can promote excessive lush growth, which can stress the grass, particularly in extremely hot weather. It can also lead to thatching and affect the surrounding water quality.

Other Factors Contributing to an Over-Fertilized Lawn

While using excess grass fertilizer is the main reason for over-fertilized plants, there are a few other reasons why your lawn may appear less healthy than expected.

Poor Drainage: Well-drained soils allow the nutrients to penetrate through the soil where your grass can absorb them. However, if your soil lacks proper drainage, minerals can accumulate on the soil surface, leading to root burn and eventual root damage.

Pet Urine: Pet urine has a high nitrogen content. This excess nitrogen can also over-fertilize your soil, resulting in localized damage and discoloration in the affected plant.

Stress: Heat, drought, and heavy foot traffic can cause stress for most plants. Prolonged exposure to these extreme weather conditions may hinder the grass's ability to effectively absorb nutrients from the lawn fertilizer. Consequently, this can lead to the build-up of excess nutrients in the soil, resembling the symptoms often associated with over-fertilization.

How to Reverse The Effects of Too Much Grass Fertilizer

Although your lawn may look like it's done for, it may not always be the case. If the grass has simply yellowed and the roots are still intact, you may still be able to revive your lawn.

Water the Lawn to Flush Out Excess Fertilizers

Rake the lawn to remove excess granular fertilizers on the soil surface. If that's not possible, distribute it as broadly as possible instead. Then, thoroughly water your grass to flush out excess nutrients for 1-2 weeks. After a few weeks, the affected area should bounce back to green and sprout new growth.

Prepare the Soil for New Grass

In a different situation, you may have to start over by preparing the ground for a new lawn. Rake the dead grass and aerate the soil to give water, air, and nutrients room to penetrate the roots of the new grass.

Conduct a Soil Test

A soil test is a proactive measure in preventing over-fertilized plants by providing insights into the soil's nutrient composition. In over-fertilized soil, a soil test kit can also help identify the nutrients and amendments your lawn needs to rebalance the soil pH and restore optimal conditions for optimum growth. This targeted information allows for more precise and effective lawn fertilization practices, preventing unnecessary or excessive fertilizer applications.

Plant New Grass

Depending on the scope of the damage, you can choose between laying new sod or transplanting grass plugs. If your entire lawn is decimated and you're dealing with more dirt than grass, we recommend sodding, which makes for an instant, dense lawn.

READ: Step-by-Step Guide to Installing Sod Like a Pro

If only small sections of your lawn are affected, you can use SodPods grass plugs to fill in sparse areas instead. Whether you're installing new sod or transplanting grass plugs, make sure to do it right by starting with a clean slate. Get rid of debris, thatch, and weeds to allow the plant's roots to establish faster and penetrate deeper into the soil.

How to Prevent Over-Fertilization

Over-fertilizing your lawn is a common mistake, often resulting from using the wrong type, applying too much, or fertilizing too often.

Moving forward, you can avoid this mistake by applying the right amount of fertilizer at the appropriate intervals. How the fertilizer is released based on your choice of fertilizer matters, too—liquid fertilizers or the water-soluble granular fertilizer varieties don't last as long and thus are prone to overuse and nutrient leaching.

Consider using a slow-release fertilizer like NutriPod® instead. Unlike liquid lawn fertilizers, it is designed to provide a consistent lawn food supply over an extended period, reducing the frequency of re-applications. The best lawn fertilizer should have the ability to offer sustained nourishment to promote grass growth without the risk of over-fertilization.

In summary, while fertilization is integral to proper lawn care, the success of establishing a healthy lawn hinges on applying it correctly and in moderation. You'll eventually have to fertilize your soil again, but this time, strike the right balance to avoid overdoing it for a consistently healthy and vibrant lawn.

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