5 Best Spruce Tree Fertilizers (And How to Use Them)

Above view of planting small spruce tree in ceramic pot

As winter rolls around and you see trees have lost their leaves, evergreens may seem better than ever. If you have a spruce tree, keeping it looking great and staying healthy might just be a priority for you. That is where fertilizer comes in.

The best spruce tree fertilizer is a high nitrogen fertilizer with a formula of 12-4-6. This formula is particularly good for spruce trees as it’s more acidic. Higher nitrogen levels in your spruce tree can aid in faster growth and a more vibrant color overall.

Below, we are going to give you some of the BEST spruce tree fertilizers, as well as tell you how and when to use them, so you ensure your spruce tree will have other trees green with envy. 

Well, what are you waiting for? Let’s dive in!

Just to add – when you shop using links from Tree Journey, we may earn affiliate commissions if you make a purchase. As an Amazon Associate, we earn from qualifying purchases.

What Is Spruce Tree Fertilizer?

Clemson Cooperative Extension’s Home and Gardening Center gives us a great explanation. Fertilizer is not ‘plant food’, as it is commonly mistaken to be, but a medium to give your tree any desperately needed minerals and nutrients.

If this does not quite make sense, Utah State University’s Extension explains the definition of fertilizer as a material that supplies one or more of the chemical elements needed by a plant for its growth. 

In fact, most fertilizers that are commonly used, and which you will probably find in stores or online, contain three fundamental elements- nitrogen, phosphorus, and potassium. This understanding of what fertilizer contains may be confusing because that sounds like ‘plant food’, right?

Not quite. These three basic plant nutrients help the plants to grow as they may lack any one, two, or three of these things. The fertilizer is, like we said above, not a ‘food’ but a way to provide this extra nutrition that a plant needs to function and grow properly. 

The three nutrients (nitrogen, phosphorus, and potassium) are not the only ones found in fertilizers, however, as some contain metals like zinc along with the other key elements. These ‘micronutrients’ may also be crucial for a plant that needs help to grow and can often help replace nutrients you did not even realize had been depleted.

Picking The Right Spruce Fertilizer For Your Tree

Organic fertilizer pouring with farmer hand

There are many kinds of fertilizers out there, but how much do you know about any of them? 

While you could just go to the store and grab the first container you spot, you will find following this advice will give you better results in a shorter time.

Trees are all different, and so are their pH levels, water retention capabilities, and nutrient needs. Spruce trees, for example, are a species requiring much less phosphorus than some other trees. This affects the type of fertilizer that will get you the biggest bang for your buck.

It is important your tree’s specific needs and not over-saturate it with anything it already has plenty of or does not need much of, to begin with.

●  High Nitrogen Fertilizer with a formula of at LEAST 12-6-4 or 10-8-6. Any kind of high nitrogen fertilizer is great, but the more the better when using Urea, which is a 46-0-0 formula, meaning it has tons of nitrogen to help sustain your plant’s growth.

●  Acidic Fertilizer. Typically, a sulfur-heavy fertilizer, these fertilizers help trees to get nutrients that might not otherwise be available to them at a different pH level. 

●  Organic Fertilizer (Compost). If you are looking for something easy and accessible, use what you have. Well-rotted compost, meaning food scraps that have broken back down into a dirt-like substance, are great fertilizers for trees.

●  Organic Fertilizer (Shredded Bark). An all-natural fertilizer means that organic is the default with this shredded bark-turned-fertilizer option. As nature intended, for fallen trees to help sustain the growth of new trees, this is an option you will not regret. Your yard will look fantastic, too… while we are talking about the benefits.

●  Combinations. Use some organic and some processed fertilizer together to nourish your spruce. This can be good when you are working to combine high amounts of nitrogen but still want to add some extra other chemicals.

So, how do you use these different types of fertilizers? Let’s first get into the specifics about each of them. 

Keep on reading, it’ll be worth your while!

High Nitrogen Fertilizer For Spruce Trees

Any high nitrogen fertilizer is going to work very well for spruce trees. 

Urea, for example, is a great option for high nitrogen fertilizers, as it has the highest percentage of nitrogen per volume. 

Let’s back up, however, for a while and talk about the ‘formula’ briefly mentioned above. What does 10-8-6 or 12-6-4 have to do with anything?

What is an NPK?

That formula is an NPK value, which deals with nitrogen, phosphorus, and potassium. Remember how we talked about those before? We are circling back.

So, it’s simple. An NPK and its 3 digits correspond to the ratio of the elements in a fertilizer. 

For example, Urea’s NPK is 46-0-0, hence why it has the highest percentage of nitrogen per volume you can find. 

So, as long as your fertilizer has a high nitrogen content (even if it is not 46% nitrogen), you will confidently be able to say you are giving your spruce a great boost. The phosphorus needs of a spruce tree are not very high, so why waste fertilizer components when you could add more nitrogen?

Why Urea For Fertilizer?

This is urea fertilizer or 46-0-0 formula

This brings us to the question, and answer, to this: why Urea?

There are 46 parts nitrogen to 0 parts phosphorus and 0 parts potassium, meaning that Urea is made of NH3 and CO2, ammonia and carbon dioxide, and makes an excellent fertilizer completely consumed by plants. Using this will help you be sure you do not leave any chemical residue in the soil around your plants.

You can find this product in local stores, chains, or even online. It is as easy as the push of a button to buy 5 pounds of Urea online for a very good rate. 

This CESCO Solutions Urea Plant Food Fertilizer can be used on both indoor and outdoor plants, ranging from vegetable gardens, trees, houseplants, and more. Funny enough, if you have some leftover and want another project, this 46% nitrogen is a great base to make handmade tie-dye products that hold color in a more vibrant way

Not only does Urea help plants grow, it lets the colors flow! What a product, this one.

Pros Of Urea Fertilizer

●  Clean fertilizer that does not leave a chemical residue in the soil

●  Cheap yet effective 

●  Safe to use

●  Good for more than just growing plants 

Cons Of Urea Fertilizer

●  Can be over-applied and cause some damage

●  Needs to be spread around by hand

●  Takes a while to take effect

How to Apply Of Urea Fertilizer To Your Spruce Tree

While you can make your own decisions regarding the placement of your high nitrogen fertilizer, there are some ways to reduce runoff and waste while increasing efficiency.

Using a sprinkler system to disperse small amounts of nitrogen fertilizer in consistent increments can help increase efficiency, as it ensures that nitrogen is not being wasted.

Another method of application is ‘surface application’, which means applying it above the soil. Similarly, combine this with the use of an irrigation system. This system does not distribute the fertilizer itself, but helps to reduce surface runoff and other issues by wetting the soil after fertilizer you apply it.

Acidic Fertilizer For Spruce Trees

Acidic fertilizer is used to help lower the pH of soil. But why, you may ask?

Well, certain nutrients are not always available to certain plants, i.e. trees, when the soil is at a higher pH level. 

So, following lots of soil testing, an acidic fertilizer may be right for your spruce. If you can take the time, let the pH level drop below 7.0 (the neutral level) and soak up all kinds of extra nutrients otherwise lost to your tree.

Pros Of Acidic Fertilizer

●  Can be great for accessing new nutrients in the soil

●  Allows your tree to not only rely on nutrients it always receives

●  Is a great way to refresh the soil around your tree and shift the growth process on a chemical level

Cons Of Acidic Fertilizer

●  Takes some time to work its magic

●  Requires pH level testing of soil and an understanding of acidity in the soil

How To Apply Acidic Fertilizer To Your Spruce Tree

You can add sulfur directly to your soil for slower results with a more enduring overall shift in your soil’s pH. However, combining sulfur with other chemicals will help you achieve a short-lived result, but also achieve it much quicker.

If you are looking for a quick, temporary fix until something else works out, we recommend combining sulfur with aluminum (aluminum sulfate.)

Otherwise, just search for some sulfurous fertilizer and be on your way!

Try this Greenway Biotech Sulfur Fertilizer, perhaps. It comes in a 5-pound bag and is ready for use.

Organic Fertilizer (Compost) For Spruce Trees

Ready made compost pile in wooden crate

Compost is a great fertilizer and can contain any organic matter. 

Most often, this is going to be seen as food scraps being put out in a compost bin or other device to collect compost. The compost then rots, or decomposes down, into a dirt-like substance all over again.

The nutrients that come directly from this other produce (plant matter all the same) will help to provide your plants with extra nutrition while you can feel good about where your food waste ended up. 

It is better for food scraps to help a spruce tree grow than end up in a landfill, right?

Pros Of Organic Fertilizer

●  Natural/organic materials

●  Cheap-free for you to use

●  Easy to put compost on older soil around your tree

Cons Of Organic Fertilizer

●  It may be less effective depending on what materials you compost

How To Apply Organic Fertilizer To Your Spruce Tree

Let your scraps decompose and turn into the compost we were discussing, and then spread it like you would any other dirt on top of the soil. Mix some of the compost down a layer or two into the older soil for better results.

Organic Fertilizer (Shredded Bark) For Spruce Trees

Shredded bark is a great fertilizer, and it is organic.

Bark decomposes more slowly because of its size, but this means that nutrients are more slowly released into the soil around your tree, which has significant effects over time.

Not only does it release nutrients at a good, slow pace, but shredded bark also helps retain rainwater and moisture (as well as any irrigated water) in the soil below, which keeps the tree more hydrated.

Another benefit of shredded bark is that it helps keep weeds away naturally, which helps maintain soil whose key role is to support the tree growing in it.

On top of it all, the shredded bark can add quite an aesthetically pleasing touch to your yard, flowerbed, the base of your tree, and anywhere else that needs a little extra TLC.

Speaking of what you can get out of using shredded bark as an organic fertilizer, the benefits outweigh any costs! 

We mean that literally; this Bonsai Jack Shredded Bark presents great value and will have your yard looking great as your tree gets a boost of its own.

Pros Of Organic Fertilizer (Shredded Bark)

●  Organic, safe to use, and easy to apply

●  Looks great in any yard or any space that your spruce tree lives

●  Help keep weeds away

●  Effects last for a long time, as bark decomposes slowly

Cons Of Organic Fertilizer (Shredded Bark)

●  Takes some time to work, as nutrients disperse slowly

How to Apply Organic Fertilizer To Your Spruce Tree

Now, this one is extra easy. Just take the bag, shake it out, spread it around, and you are done! 

Make sure your fertilizer covers the rest of the soil directly surrounding the tree and you will be just peachy. 

Does it seem too easy to be true? We promise it is not! You get a great outdoor space and your tree gets extra nutrients over a long period, which is a win-win!

Combinations Of Fertilizers

A combination is going to work best when you have some organic material at home that is good for your spruce but may not be enough for your intended purpose. 

Say, for example, you’ve got tea leaves, for which the formula is about 4-1-1. This is good in the sense that nitrogen is its main chemical, but there’s not much of anything when you look at the formula, totaling a whopping 6% NPK. 

If you don’t want this to go to waste, consider adding some other acidic or nitrogen-heavy fertilizer to the mix. Your tree will reap the benefits of both mixtures while you make use of your food waste and get to save some cash. 

Pros Of Combining Fertilizers

●  An environmentally friendly option

●  Sustainable and inexpensive for you

●  Includes multiple formulas of fertilizer to create an impressive combination of nutrients

Cons Of Combining Fertilizers

●  Might not have the same effect as a processed fertilizer which has specifically designed formulas

●  It may take a little longer to work, depending on what you combine

How to Apply Combined Fertilizers To Your Spruce Tree

This one depends on what products you are using, but on top of the soil with a little water sprayed on top is probably a safe bet!

Simple Ways To Help Your Spruce Tree Grow

Blue spruce tree branches

There are plenty of fertilizers out there, as you now know, but what are the other ways you can work to help your spruce tree grow?

Monitor The Health of The Your Spruce Tree

Stunted growth, galls, and dead branches are all signs of a tree in decline. This can occur for many reasons, including but not limited to insects, disease, or low access to water or nutrients.

By monitoring the health of your tree, seeing how it progresses over time, you can nip an issue in the bud when it does arise. The alternative, not noticing your tree is declining until it is already too far gone, is one we want to help you avoid at all costs.

A tree will not grow taller, wider, or overall larger if it is fighting disease or infestation. So, keep watch and stay on top of your spruce tree’s health.

If you have a blue spruce tree, check out our guide on how to make your blue spruce more blue here.

Use An Insecticide For Your Spruce Tree

On that note, insect infestations are difficult to deal with and not at all a welcome surprise.

If you are struggling with insects infesting your spruce tree, causing your tree to be eaten, its foliage to be consumed, or galls and egg sacs to appear, take action to resolve the problem right away.

Try DEBUG- Organic Pest Control for Plants which uses neem oil, azadirachtin, and more to protect your tree and its lovely leaves from annoying little pests and all the rest. Soon you will rid yourself of all the insects trying to infest.

This insecticide is a concentrate, which means you get more for your money, with a container producing enough concentrate for 22 bottles of insecticide. Not only is it field-tested and farmer approved, but it is also a great organic alternative to other products and you can safely use it until the day of harvest. 

A product that works against 200+ pests, you will not even need to figure out the specifics of what bugs may breed in your tree. Just spray and watch them all go away!

Make Sure Your Spruce Tree Has Enough Water

So, fertilizer is not the only thing you can add to your tree to make sure it has enough of what it needs. 

Adding some supplemental water to your soil every once in a while, if you are not already doing so as part of your fertilizing routine, is a great way to keep your spruce healthy and hydrated.

Everything needs water. People, trees, animals, even plants that live in the desert have their reserves. Keeping up with those needs of your spruce will also help it flourish at the rate it should.

If you need to keep your blue spruce tree small, read our guide: 6 Simple Steps To Keeping A Blue Spruce Tree Small.

That’s It For Now!

Spruce trees are generally healthy, especially being evergreens, but everyone can use a little extra care every once in a while, including these green giants. Now you know what to look for in a spruce tree fertilizer, to ensure your tree gets the right nutrients sustainably for you to use and for the environment to receive. 

From high nitrogen fertilizers like Urea’s 46% nitrogen product to using shredded tree bark as purely organic material, there are a good number of solid ways to help maintain good growth in your tree. 

Remember, fertilizers are not plant food (even though some of them are branded as such), but they are a way to help your trees and other plants soak up the extra nutrients they need to not only survive but thrive. 

We hope this article helps you feel confident in how you help your plants as you embark on your tree journey. 

Until next time, thanks for reading!


Adeniyan, O. N., Ojo, A. O., & Adediran, J. A. (2011). Comparative study of different organic manures and NPK fertilizer for improvement of soil chemical properties and dry matter yield of maize in two different soils. Journal of Soil Science and Environmental Management, 2(1), 9-13.

Mahendrappa, M. K., & Salonius, P. O. (1982). Nutrient dynamics and growth response in a fertilized black spruce stand. Soil Science Society of America Journal, 46(1), 127-133.

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  1. Thank you for this advice. I just moved to an antique house, where the trees have been completely ignored and are suffering. I had to remove two spruce trees that were 95% dead, with mites and/or fungus. I have two more suffering, so will try some of your remedies. For urea, couldn’t one just collect one’s urine and apply it? Or use horse manure, because that is mixed with wood shavings (similar to shredded bark?).
    As for the organic pest product, it has neem oil. I know people view it as organic and safe, but I read that it kills bees by disabling their digestive system. I’d not want to kill any bees, and especially not the two hives I’m about to pick up, as a beginner beekeeper.

    1. It reminds me of our new home we moved into and had to take out 3 rotten pines immediately. Good luck with the move. As for urea, you could do that, but there’s the issue of everything else in your ‘homemade solution’ that could adversily affect the tree and the matter of consistency to where you wouldn’t be able to effectively gauge the concentration levels. That being said, I encourage you to do your own research on that one 🙂 Horse manure can be a good option for the nitrogen content while being lower in P & K but then you have the issue of it being yanno, horse manure, and all the nasty things that can come with it. I won’t recommend that as I don’t have experience with manure, but it’s probably a serviceable natural option. But that requires you to know that the tree has a definite nitrogen deficiency and that’s all that’s wrong.

      Neem oil can potentially have that effect, there’s well sourced information on both accounts of being OK for bees but potentially harming them as well (afterall, it’s an insecticide.) What I would reccomend is to have an arborist come out to your home visually inspect it to A: make sure it can be saved and that there isn’t a detrimental fungus in them and B: offer an organic treatment option to nurse the tree back to health.

      Keep me updated on this and feel free to send some images through our contact form, would love to see the trees and make sure they can be saved!

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