Best Fertilizer for Trees and Shrubs in 2021 – Reviewed and Fertilizing Guides

Many people spend a lot of time worrying about fertilizing their vegetable garden or flower beds. But did you know that your trees need fertilizer, too?

Trees and shrubs are susceptible to many of the same problems that your other plants are, and fertilizer can help. If you’re looking for the best fertilizer for shrubs and trees, keep reading for our top picks.

How Can I Tell If My Trees Need to be Fertilized?

There are multiple ways to tell if your trees and shrubs need fertilizing, including:

Stunted growth

Stunted growth is when you notice that your shrubs and trees have stopped growing or aren’t growing as quickly as they should be. You may notice that a tree in one area of your yard is shorter than one on the other side or than one in your neighbor’s yard.

Thin or patchy foliage

Thin or patchy foliage is when your tree or shrub doesn’t have as many leaves as it should. There are many reasons for this, though one of the most common is a lack of nutrients.

Yellow leaves

Some young leaves start yellow and turn green as they mature throughout the summer. That said, by summer, they should be fully green and mature. Yellow leaves can be caused by multiple things, including insects, drought, or lack of nutrients.

Dropped leaves

Some trees naturally drop leaves throughout the summer, but if the problem is severe, there are a few things that may be causing it. The most common problems are insects, diseases, and too much or too little water.

Insects and diseases

All trees, shrubs, and plants are susceptible to insects and diseases. Some can be treated easily, but others cannot. While fertilizer may not necessarily be a direct treatment for insects and diseases, it can make the tree stronger so it has a better chance of recovery.

What Happens to Trees That aren’t Fertilized?

Trees and shrubs that aren’t fertilized are susceptible to many problems, as mentioned above. But why do you have to add fertilizer?

In forests and woodlands, the soil is different. The main reason is that old leaves, berries, branches, flowers, and animals decompose, adding necessary nutrients to the soil. The trees use this to grow and thrive.

The soil in your yard is more compact, and the roots can’t penetrate it as easily as trees in the forest. There’s also a chance that the contractors used subsoil when building your home, and the area where your trees are growing is just not enough to support them.

Finally, the soil in your yard isn’t naturally replenished. Your shrubs and trees may grow fine for a few years, but eventually, they will deplete the nutrients in the soil and you’ll have problems.

The 7 Best Fertilizers for Your Trees and Shrubs

Now that you know a little more about why shrubs and trees need fertilizer, let’s take a look at seven of the best products out there.

Pictures	Tree and Shrub Fertilizers	NPK Fertilizer Analysis
	Jobe's 01660 1610 0 Tree Fertilizer Spikes	16-4-4
	Miracle-Gro Tree & Shrub Plant Food Spikes	15-5-10
	Scotts Evergreen Flowering Tree & Shrub Continuous Release Plant Food	11-7-7
	Miracle-Gro 3002410 Flowering Tree and Shrub Continuous Release Plant Food	18-6-12
	Ross 14636 Root Feeder Refills	25-10-10
	Jobe's 01661 Evergreen Fertilizer Spikes	13-3-4
	BIOADVANCED 701910A Tree and Shrub Protect and Feed	2-1-1

Best Fertilizer for Shrubs and Trees Reviews

1. Jobe’s 01660 1610 0 Tree Fertilizer Spikes

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These pre-measured fertilizer spikes from Jobe’s deliver a constant supply of nutrients under the soil where the roots are actively growing. Each has just the right amount of nutrients and slowly releases them to your trees and shrubs over time.

Jobe’s fertilizer spikes are good for all shrubs and trees, including magnolia trees, juniper trees, and cypress trees. Not only are they easy to use, but there are also no hazards, no strong smells, and no runoff.

All you have to do is insert the spikes around the tree’s drip line when the ground is wet, once in early spring and again in late fall. For shrubs, you need one spike for every three feet of height. For trees, it’s one spike for every inch of trunk diameter.

(Note that each pack comes with 15 spikes. Depending on the size of your trees and how many shrubs you have, you may need more than one to fertilize your whole yard).

2. Miracle-Gro Tree & Shrub Plant Food Spikes

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Miracle-Gro is well known for its many plant-care products. The brand’s tree and shrub plant food spikes are easy to use and feed your plants continuously, right at the roots.

These spikes are great for a wide range of shrubs and trees, including evergreens and plants that prefer acidic soil. Generally, these plants use a lot of energy in the spring when they’re putting out new leaves and producing seeds, so they need more nutrients in this period.

Miracle-Gro recommends using these fertilizer spikes one in the spring and again in the fall for best results. They’re easy to use and support healthy growth so your trees and shrubs produce more lush, beautiful leaves than before.

To use, make sure the ground is wet. Then, insert the spikes into the soil at least two inches under the surface. For trees, apply them around the drip line, keeping them at least three feet apart. For shrubs, insert spikes two feet away from the center of the trunk.

3. Scotts Evergreen Flowering Tree & Shrub Continuous Release Plant Food

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Scotts continuous release plant food for flowering shrubs and trees feeds for two months. It supports root and foliage growth and is easy to use. Just apply it evenly, directly from the bag to the soil, rake it into the top two or three inches, and water thoroughly.

This product is great for a range of trees and shrubs, from evergreens to dogwoods, magnolias to hydrangeas, and many other plants that like an acidic environment. When used properly, it’s perfectly safe for your plants and won’t burn the roots.

The easy-open bag seals for easy storage, which is great because you only need a half-tablespoon per square foot. If you have a large area to cover, multipacks are available, so you can buy them in bulk.

4. Miracle-Gro 3002410 Flowering Tree and Shrub Continuous Release Plant Food

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Another option from Miracle-Gro is this fertilizer for flowering shrubs, trees, and other plants that prefer acidic soil. It includes natural ingredients, like kelp, earthworm castings, bone meal, and feather meal. These ingredients nourish the soil and feed the microbes that help your plants absorb nutrients easily.

Something we like about this fertilizer is that you can use it on the ground and in containers. It’s a versatile product that you can use for a variety of plants.

One application lasts for three months and supports strong, healthy roots which, in turn, improves water efficiency. This plant food is available in multiple sizes, including one, 4.5, and eight-pound packages. If you need a lot, you can also buy the eight-pound bags in packs of four.

5. Ross 14636 Root Feeder Refills

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These Ross root feeder refills are made to give you healthy, lush shrubs and trees, all season long. There’s no mixing or measuring, so they’re really easy to use. Plus, you don’t have to worry about any runoff or wasted product.

Each pre-measured refill contains a high-nitrogen formula for quick and easy mess-free application. Ross recommends applications in the spring and summer to support your plants during the active growing season and then again in fall to prepare for winter dormancy.

One thing to note is that this product is meant to be used with the Ross Root Feeder, a special tool designed to deliver fertilizer deep under the surface of the soil. Just hook the feeding device up to your garden hose, and the water carries the fertilizer right down to the roots.

6. Jobe’s 01661 Evergreen Fertilizer Spikes

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If you’re looking for a fertilizer for shrubs and evergreen trees, take a look at this option from Jobe’s. Each premeasured spike delivers nutrients right to the roots for a continuous feeding underground that lasts the entire season.

This formula is ideal for spruces, junipers, and other evergreens. These spikes are easy to use, just insert the spikes into the tree’s dripline. You don’t have to worry about runoff or hazardous waste, and there’s no harsh smell.

According to Jobe’s, this product should be applied at the beginning of spring and later into the fall for best results. Water the ground before you insert the spikes and use the handy chart on the back of the package to figure out how many spikes you need per tree or shrub. One package comes with 15 spikes.

7. BIOADVANCED 701910A Tree and Shrub Protect and Feed

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Looking for a tree and shrub fertilizer that you only have to apply once every 12 months? This product from BIOADVANCED might be just what you’re looking for. This fertilizer is easy to apply, too. Just shake the granules around the plant every fall for feeding and protection throughout the fall and winter.

Another great thing about this product is that it does more than just feed your plants. It also protects them against 40 different harmful insects, including aphids, emerald ash borers, scale, and leafminers.

The granules come in a four or ten-pound container with an applicator right in the lid. There’s also a liquid concentrate available in a 32-ounce bottle that offers the same benefits. Both can be used on shrubs, single and multiple trunk trees, and container trees.

When is the Best Time to Fertilize Trees and Shrubs?

Every product comes with different recommendations, and you should always follow the directions that come with the fertilizer you choose. That said, there are some general things to think about when it comes to choosing when to fertilize your shrubs and trees.

Most products and experts recommend fertilizing in the fall. This may seem a little weird since it’s right before the winter when many plants are dormant, but when you think about it, it makes perfect sense.

By fertilizing in the fall when the temperature is regularly below 40 degrees F, plants naturally produce what they need to survive the cold weather. When you fertilize in the fall, you’re giving the plants what they need to survive the winter.

But you can’t just fertilize at any point during the fall. It’s best to wait until the end of October or early November so that you don’t stimulate new growth. Instead, you’ll encourage the roots to grow and stay strong through the winter months.

If you have an established tree or shrub that is showing any of the signs mentioned earlier – if it has small or pale leaves, dead branches, insect damage, or disease – it’s safe to assume it needs fertilizer.

That said, there are some instances when you shouldn’t fertilize trees, bushes, and shrubs. Anything newly planted needs to establish roots before fertilizer will help. And most established, mature trees won’t need fertilizer every year.

Some people also recommend fertilizing again in the late winter or early spring, between late February and April, though this will depend on the product you choose and how often it is meant to be used.

Whatever you do, don’t fertilize toward the end of summer or early fall. Giving your shrubs and trees too many nutrients at this time can stimulate new growth when the plant is supposed to be slowing down and preparing for dormancy.

How to Fertilize Trees and Shrubs?

How you will fertilize your shrubs and trees depends on the type of product you’re using, but there are some general methods to consider.

No matter which method you choose, the most important thing is that you put the fertilizer in the right spot. With flowers and vegetables, you’re probably used to applying fertilizer right at the bottom of the plant.

With trees, it’s a little bit different. The main roots of trees are in the top foot or so of the soil. That’s why most of the fertilizers we recommended come in spike form, so you can push them into the ground to get the nutrients as deep as you can.

Fertilizer spikes are easy to use, but if you put them in the wrong spot, they won’t do what they’re supposed to. Instead of putting the fertilizer at the base of the trunk, as you would with other plants, you have to place it around the drip line.

The drip line is the area directly underneath the outer rim of the tree branches. It’s called the drip line because this is where any excess water from the tree’s canopy drops to the ground.

An easy way to picture it is to imagine the tree in an umbrella. The drip line is the place where the water would drip from the umbrella and hit the ground in heavy rain.

Why is the drip line important? Because it’s where the most absorption takes place. The trunk and large roots toward the center give the tree stability while the tiny terminal roots absorb nutrients and water.

Avoid watering and fertilizing close to the trunk as this can cause problems for the tree, most common root rot.

The method for fertilizing shrubs is closer to how you would apply fertilizer to a large plant in your garden. Add granules or spikes around the base of the shrub, following the instructions on the package of the product you’re using.

When using granules or spikes, it’s also important to water the fertilized area soon after it is applied if it hasn’t rained. Watering the fertilizer in is the only way to get it down to the roots where the tree can use it.

Liquid fertilizer is also an option, but be sure to follow the instructions on the packaging carefully.

We also included an item on our list, Ross 14636 Root Feeder Refills, that requires a root feeder. This tool attaches to your garden hose and is inserted into the ground. When you turn the hose on, the water runs through the fertilizer, carrying it into the soil.

Essentially, this tool gets the water, and therefore the fertilizer, deeper into the ground and closer to the roots. Remember, though, you still need to make sure the fertilizer gets near the drip line or it won’t be effective.

How Often Should You Fertilize Trees and Shrubs?

The short answer is that you should fertilize shrubs and trees as often as they need it.

The long answer is a little more complicated. The best thing you can do is a soil test to determine if your soil needs fertilizer and what kind of fertilizer it needs.

As we mentioned, it’s a good idea to fertilize your trees and shrubs in late fall, when the temperature is consistently below 40 degrees F. This will help them grow strong roots to survive the cold temperatures of winter without risking stimulating new growth.

From there, you have to watch your tree and your soil and decide what’s best for you. Some products claim they work for three months while others say 12. You can assume it’s safe to apply them on the timetable recommended by the company.

That said, remember not to apply fertilizer in late summer or early fall. If you use a product that feeds for three months and it’s mid-September and time to reapply, skip the application and wait until spring.

Also, remember that established shrubs and trees most likely will not need to be fertilized every year. Again, the only way to know for sure is to test your soil to see if it does need fertilizer or any other amendments.

Conclusion

Many people don’t even think about fertilizing trees and shrubs. Sure, we worry about our gardens and flowers because they come and go every year and it’s easy to tell when something’s wrong.

It’s easy to overlook a tree, but you really shouldn’t. Shrubs and trees stay the course. They come back year after year, and it’s important to take care of them.

Neglecting your shrubs and trees can lead to many problems. It can cause them to lose their leaves and stunt their growth, and it makes them more susceptible to disease and insect infestations.

If you’re looking for the best tree and shrub fertilizer, check out the products mentioned above. They’re all great products that will help keep your trees and shrubs happy and healthy.