How To Keep Lawn Fertilizer Out of Your Garden

A healthy and happy garden is what every gardener wants. Sadly, there are environmental hazards that sometimes make that complicated. One of those hazards is the leaking of lawn fertilizer. 

Here’s how to keep lawn fertilizer out of your garden:

  1. Build an underground barrier around your garden.
  2. Create a garden bed to raise it.
  3. Don’t plant your garden near a lawn.
  4. Try to avoid using lawn fertilizer.
  5. Switch to organic fertilizer.
  6. Wash the soil and plants if fertilizer gets in your garden.

Continue reading this article to learn how to keep lawn fertilizer out of your garden. I will also discuss why lawn fertilizer can harm your growing garden. 

1. Build an Underground Barrier Around Your Garden 

Lawn fertilizer is made for lawns rather than vegetable plants and flowers. If added to a blooming garden, it can cause hazardous side effects that weaken and destroy your plants. Luckily, there are fantastic ways to protect your garden from harm’s way. 

One of the most popular solutions for protecting your garden is to build an underground barrier under the soil. 

Building a barrier can prevent leaking lawn fertilizer from touching your plants. You can find a durable material to use at a home improvement store that will last for many years. One great option that is recommended is a pond liner. You can also use a tarp, painter’s plastic, or even black garbage bags.

The point here is to find something waterproof and fertilizer-proof to protect your garden. Here are a few steps to follow when building an underground barrier for your garden: 

  • Dig a large trench where your garden will be planted. The trench should be as large as your garden and a few feet deep. Your barrier should be installed underneath the soil for it to work properly. 
  • Install your barrier into the trench. If you can, make sure the material is snug in place without being set in a dug out corner. Sometimes, corners can cause the barrier to move once the garden is planted.
  • Fill the trench with layers of soil. This step is important, especially for removing air pockets that are present. Gardeners should make sure the soil is also evenly distributed and covers the entire barrier. 
  • Plant your garden. Once everything is installed, you can plant your garden into the soil and begin fertilizing appropriately. Sometimes, adjustments might need to be made in the future, so watch over your garden accordingly. 

If you are interested in using this type of barrier, it is recommended to speak with an expert at your local gardening store or similar for assistance. They can provide information and guidance in much detail. 

2. Create a Garden Bed To Raise It

The effects of lawn fertilizer can be traumatic for your garden. Gardeners who have experienced the toxicity of lawn fertilizer will do anything to protect their plants from it and chances are, you will, too. 

Although using a protective barrier is a great option, there are also other fantastic solutions to consider. One of those is a raised garden bed.

Garden beds are raised off of the ground and in their own area, away from lawns, and it’s the perfect way to keep your plants safe from wandering fertilizer that may taint the groundwater and soil. 

They are also very helpful for gardeners. When gardening, individuals must bend over and it can be tedious for the body. Luckily, gardeners can save a lot of energy by gardening in a bed that is raised. 

If your main intent when installing a garden bed is to protect your garden from lawn fertilizer, you’ll want to find a bed that is raised off of the ground. Garden beds that are installed on the ground may not help plants with the soil that is under the surface. 

They can be hand-built or purchased online and installed.

3. Don’t Plant Your Garden Near a Lawn 

Many gardeners know that lawn fertilizer is not meant for plants, as it can create fertilizer burn and other negative symptoms, harming your garden. Unfortunately, most gardens are located near lawns. Luckily, individuals planning to plant a garden or change the location of their garden can find a place that is far away from lawns. This can preserve the health of the soil and plants. 

Although this is an uncommon solution, it is a helpful option to consider if there is a lawn nearby.

However, this solution might not fix the risk of exposure either. But, it can lower the chance that your garden may interact with lawn fertilizer. This is a great solution for those seeking a precautionary option. 

Additionally, you can also communicate with neighboring areas. Sometimes, lawns may exist out of your reach, and tainted groundwater, unfortunately, can interact with the soil. 

Individuals can communicate with their neighbors to receive more information about the fertilizers in use nearby and how far certain lawns are from their garden. If not, owners should choose to, at the very least, keep a lookout often for their garden. 

Sometimes, however, you might have neighbors who won’t listen or work with you about fertilizers and pesticides. 

In that case, you’ll either need to give up on a garden while you live next to them or try the other methods listed in this article. Unfortunately, not everyone is nice enough to work with their neighbors for the common good of the neighborhood.

4. Try To Avoid Using Lawn Fertilizer

Many gardeners have gardens and lawns in their yards. Although they may not be next to one another, it can feel challenging to care for a garden and lawn simultaneously. Luckily, there is a solution. 

Gardeners can dilute their lawn fertilizer with water to lower the level of toxicity that is present. The main problem with lawn fertilizer is the toxicity of chemicals, which can harm plants. If not diluting, gardeners and homeowners can avoid using fertilizers on their lawn, especially synthetic blends. 

There are additional ways to care for your lawn without adding fertilizer: 

  • Avoid using fertilizers and, instead, use additives. There are certain additives you can use on plants like coffee grounds, compost, or other types of ingredients. The most important aspect of your lawn’s health is the soil. 
  • Test your soil often for pH and nutrient levels. There are many great soil tests on the market that can give you information about the condition of your lawn’s soil. You can treat your lawn with basic ingredients. 
  • Use vinegar and other ingredients to help with weed maintenance. Essential oils, vinegar, and other options can help tame the weeds that might grow on your lawn. Fertilizers help with overall health as well as other types of lawn care products that have active ingredients but do release chemicals. 

5. Switch To Organic Fertilizer

Valuing your garden is an important step to take and most owners will do what they can to help their plants feel nourished and healthy. Unfortunately, many gardeners care for plants in a backyard space that also has a lawn nearby in need of fertilizer to grow. 

Individuals can switch to an organic lawn fertilizer to help protect their garden from fertilizer burn, which is most common with synthetic fertilizers. However, your garden may still be at risk for fertilizer burn with organic fertilizer because of the ingredients that it contains. 

Synthetic fertilizers have many chemicals that release quickly. The ingredients and process of application are also very different from organic fertilizer. However, this fertilizer can be more expensive and results take a bit of time. 

On the plus side, organic lawn fertilizer is natural and the numbers of nitrogen, phosphorus, and potassium are much lower, which can help protect your garden. You can find an organic fertilizer that has the numbers you want easily. Most synthetic fertilizers contain few ingredients at a high volume.

Lawn fertilizers do have high amounts of N-P-K ingredients in general. Fertilizers used for gardens have lower numbers and different amounts. Luckily, you can research and choose a fertilizer that works great for you and your garden. 

6. Wash the Soil and Plants if Fertilizer Gets in Your Garden

Although there are many ways to help your plant avoid lawn fertilizer altogether, sometimes precautionary steps don’t work in the way we had hoped. Luckily, there is a way to help your plant recover from exposure to lawn fertilizer.

The most important aspect of a garden is the quality of the soil. If your garden has been fertilized with lawn fertilizer, chances are you will need to water down your soil. Watering down the soil is the process of soaking the soil with water to wash out any fertilizer, which can happen over a week. 

Here are a few suggestions to follow when washing your soil:

  • Fill your soil without overflowing it. Soil needs a lot of water when you wash it, but it’s important to make sure you fill it up without adding too much. Too much can cause the lawn fertilizer to spread throughout the rest of your garden. 
  • Wash your soil for seven days. Washing your soil is an important step and must be accomplished over a week. If you only wash your soil for one or two days, you may not have positive results. 
  • Trim the leaves if they are yellowing or browning. Sometimes, fertilizer can cause fertilizer burn, and symptoms will show up in your plants. Individuals can trim away burned or withering parts of the plant. If your root is weak and black, re-planting might be required. 

Do I Need To Protect My Garden if a Lawn Is Not Nearby?

Creating a nourishing environment for your garden to grow is what matters at the end of the day. If you have other plants and lawns nearby, you may feel concerned for your garden’s ability to flourish. This worry might even arise if a lawn is not nearby. 

You need to protect your garden if a lawn is not nearby because lawn fertilizer can easily spread. Lawn fertilizer is used by many and can travel through water, soil, and other environmental factors. 

It may appear as if lawn fertilizer only leaks into a garden if there is a lawn nearby, but that is not always the case. Lawn fertilizer can leak and spread from one area of the soil to another through environmental factors.  

Lawn fertilizer can soak into the soil and spread through the groundwater. Rain and other environmental factors can also move fertilizer from one location to another once it is on the ground. 

Gardeners and plant owners should observe their surroundings to see if lawn fertilizer may be nearby. After making an evaluation, proper precautions can be taken. 

Creating distance between your garden and a lawn is a precautionary step that gardeners can take to protect their plants from the negative exposure that lawn fertilizer can cause, as previously mentioned. However, it is not a solution that guarantees full protection. 

Here are a few fabulous precautionary steps that gardeners can take: 

  • Separate your garden from any lawn nearby, making sure lawn fertilizer is out of reach.
  • Create strong barriers like a raised garden bed or an underground barrier.
  • Check your surroundings, and communicate with the neighboring area. 
  • Watch over your garden frequently and test your soil for nutrition levels. 
  • If lawn fertilizer is used, store the extra fertilizer in a safe place where it might not spill or come near your garden. 

What Is Fertilizer Burn?

Gardeners and plant fanatics have begun to realize the benefits and disadvantages of fertilizer. Most disadvantages come from minor mistakes that happen during the gardening process. One of those common mistakes is fertilizer burn.

Fertilizer burn is when your plants begin to burn and decay from over-fertilization or if the wrong type of fertilizer is fed to your plant. Your plants will begin to suffocate and dry out from the ingredients. The most common additive that can harm your plants is salt. 

Many plants experience fertilizer burn and it is not fun for gardeners. Too much fertilizer can scorch your plants and they will start to decay. Luckily, your plant can live through the horrible experience of fertilizer burn if caught right away. 

The biggest concern for plants is the continual spread of fertilizer throughout the soil, which can happen if gardeners do not catch the problem in time to help mend their plants.  

Gardeners should look for the following symptoms of fertilizer burn: 

  • There may be a pest infestation in your garden. 
  • The production of your fruits and vegetables has stopped.
  • Your plants are beginning to rot.  
  • The leaves on your plant are withering away, browning, and curling inward. 
  • There is a noticeable discoloration in your plant’s roots, which includes brown and possibly black. 
  • You may notice a crust-like appearance around your plant that looks like salt. 
  • There is impaired growth. 


Lawn fertilizer is a fantastic option for lawns, but it can be detrimental to gardens. Whether you have experienced lawn fertilizer in your garden or not, it is always best to curate protective mechanisms for your garden, so your plants can thrive in a healthy environment. 

At the end of the day, no one wants to experience fertilizer burn. Do your research, if you can, and find the right tools to begin protecting your plants and your soil. 

This will make your life a whole lot easier as a thriving gardener. 

You can read my other article on fertilizing indoor and outdoor plants here: How to Fertilize Indoor & Outdoor Plants (Ultimate Guide)

Alexander Picot

Alexander Picot is the principal creator of, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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