Can Fertilizer Spikes Kill Trees? What You Need To Know

Fertilizer spikes are useful products that easily add nutrients to the soil. Many fertilizer spikes on the market are made specifically for trees, but are they safe to use?

Fertilizer spikes can kill trees if you install too many of them too close to the tree trunk. It’s easy to avoid this by placing the recommended amount of spikes along the tree’s dripline. The number of spikes you’ll need will depend on the diameter of the dripline.

The rest of this article will discuss using fertilizer spikes for trees in greater detail. It will also discuss the pros and cons of fertilizer spikes, how to install them, and whether they’re better than regular fertilizer.

Are Fertilizer Spikes Good for Trees?

Fertilizer spikes are good for trees because they give the roots and surrounding soil essential nutrients. These nutrients generally include phosphorus, potassium, and nitrogen. Using fertilizer spikes correctly will help your tree to thrive.

Many people prefer to use fertilizer spikes over regular fertilizers because they’re quick and easy to install. Plus, there are fertilizer spikes that are designed for trees, so you can be sure they’ll get all the nutrients they need without having to take measurements.

How To Avoid Killing Trees With Fertilizer Spikes

Although fertilizer spikes are beneficial for trees, killing a tree is possible if you’re not careful. Thankfully, most fertilizer spikes you purchase will come with instructions that tell you how many you’ll need to use and where to put them. 

The bigger the diameter of the dripline, the more spikes you’ll need. If you use more spikes than what’s recommended, you may over-fertilize. This could lead to issues like root damage and even tree death. You may also notice the foliage changing color if the roots are damaged due to over-fertilization.

Problems can also occur if you apply the fertilizer spikes too close to the tree trunk. You must remember that tree roots spread out—they don’t just grow downward into the soil.

Because of this, it’s not necessary to apply fertilizer spikes directly where the tree trunk is. If you do so, you’ll cause more harm than good and might kill your tree eventually. Keeping the fertilizer spikes at the dripline will ensure your tree doesn’t die from the excess nutrients.

Fertilizer Spikes for Trees: The Pros

Now that you understand the basics of why fertilizer spikes can be helpful to trees, I want to discuss their pros in greater detail. It’s good to know exactly why they’re helpful before installing them next to your tree, so read this section to learn about the main advantages of fertilizer spikes!

Over-Fertilization Is Less Common

When it comes to fertilizer spikes, over-fertilization is less common than it is with traditional fertilizer. That’s because the spikes are already measured out and contain all the required nutrients—nothing too much, nothing too little.

According to a study by the University of California, applying too much fertilizer raises salt concentration in the soil. This causes a host of issues for trees and plants. Since it’s more challenging to over-fertilize using spikes, you won’t have to worry about these issues as much.

With standard fertilizer, it’s easier to apply too much because you have to spread it around the soil. Most fertilizer spikes come with instructions that tell you how many you’ll need to use, significantly reducing over-fertilization risks.

You Don’t Need To Measure Fertilizer

Fertilizer spikes come packaged and ready to be placed into the ground. You don’t need to measure anything or determine what nutrients you need to give to the soil. All you need to do is choose the appropriate fertilizer spikes for your tree type. 

There are two common types of fertilizer spikes:

  • Evergreen tree spikes
  • Deciduous tree spikes

Let’s say you have an evergreen tree in your yard. If you want to use regular fertilizer, you’ll need to find an appropriate one and figure out the best nutrients for your tree. This can be challenging if you don’t know what you’re doing—you could end up using a fertilizer that’s not appropriate for your tree.

With a fertilizer spike, you can pick up one made specifically for evergreens without having to guess which ingredients you’ll need.

Easy To Install

Easy installation is another benefit of using fertilizer spikes. When it comes to regular fertilizer, you need to spread it around the soil in the hopes you’re putting it in all the right places. 

With fertilizer spikes, all you need to do is hammer them along the dripline without guessing or figuring out the best places to leave them. 

The Spikes Are Compact

Another thing to consider is how easy it is to carry and transport fertilizer spikes. Regular fertilizer usually comes in large bags, which can be extremely heavy. This is inconvenient if you have a large yard and need to fertilize a lot of the soil. 

Spikes are much easier to carry, and you don’t need to bring any more than you need. All you need to do is bring the number of spikes you’ll be using and leave the rest behind. This certainly beats lugging around a giant bag of fertilizer!

Fertilizer Spikes for Trees: The Cons

I’ve discussed the main pros of fertilizer spikes, but I want to discuss the main cons now. Luckily, there aren’t too many cons to be aware of, but it’s still good to know what they are. 

It’s essential to consider the pros and cons of fertilizer spikes before using them for your trees, so read this section to learn more.

Spikes Are More Expensive Than Regular Fertilizer

One factor to consider is price. Unfortunately, spikes are more expensive than regular fertilizer. However, since they are so compact and easy to install, the higher price may be worth it. 

Still, if you’re on a tight budget and looking to spend as little as possible, you might want to use regular fertilizer instead.

Fertilizer Spikes Don’t Spread a Lot

To install fertilizer spikes, you must place them in specific spots around the tree. Because of this, the fertilizer doesn’t spread very much across the soil. On the other hand, when you use regular fertilizer, you can spread it around much more easily. 

Because of this, the nutrients from fertilizer sticks can sometimes be a little uneven in the soil. If you want complete freedom to spread the fertilizer wherever you want, you’ll probably want to use standard fertilizer instead of spikes.

Installation Requires Some Physical Strength

Although installing fertilizer spikes is super straightforward, it does require some strength. This is mainly because you need to hammer the spikes into the soil, which can be challenging for some people, especially those that are older. It can also be difficult if you have dense clay soil instead of sandy soil. 

As you can imagine, it’s more challenging to penetrate dense soil with a fertilizer spike, so you should keep this in mind before deciding to use them. The more dense and clay-like your soil is, the more strength it will take to hammer the spikes into the ground.

The Best Way To Install Fertilizer Spikes for Trees

The best way to install fertilizer spikes for trees is to apply them along the dripline, and this relates to every kind of tree. You should install them twice a year—once in the spring and once in the fall season. It’s good to do this because the fertilizer spikes will wear away over time. Adding new ones twice a year will keep your trees thriving indefinitely.

As I mentioned earlier, most fertilizer spikes will come with instructions that you should follow for the best results.

Are Fertilizer Spikes Better for Trees Than Fertilizer?

Fertilizer spikes are not better for trees than fertilizer because they don’t cover a broad section of the soil. It’s best to use a regular fertilizer to get nutrients across the dirt. However, fertilizer spikes are a good choice if you want something easy that doesn’t require much planning.

According to the University of Florida, broadcast fertilizers work best on trees because they give nutrients to the whole area rather than just a tiny section. 

Even still, fertilizer spikes work well and are favored by many. It’s up to you to decide which type you’d prefer. If you’re looking for something that will cover a broad section of the soil adequately, standard fertilizer is better.

If you want something easy to install and don’t want to figure out the specific nutrients and ingredients you need, spikes will do the trick just fine.


Fertilizer spikes can kill trees if you use too many of them or place them too close to the tree trunk. Your trees won’t die if you follow the instructions, and don’t use too many spikes.

If applied correctly, fertilizer spikes benefit trees by providing the roots with essential nutrients. Without these nutrients, your tree won’t be able to thrive. 

Although fertilizer spikes are easier to use (especially for beginners), regular fertilizer can cover more soil and is usually ideal. However, spikes can be a good alternative.

If you’re wondering how many fertilizer spikes you need per tree, this article is for you: How Many Fertilizer Spikes Do You Need per Tree?

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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