What is 12-4-8 Fertilizer Good For? | The Ultimate Guide

12-4-8 is a fertilizer that contains 12% nitrogen, 4% phosphorous, and 8% potassium.

It works great for most plants because it contains all three macronutrients, but there are limitations.

Read on to learn about what 12-4-8 fertilizer is, what it is good for, and when to use it.

What Does “12-4-8” Mean?

As I mentioned earlier, it shows the ratios of three macronutrients.

You must remember three words to remember NPK.

Up, Down, and All-around

Here’s why these are important for your plant.

Nitrogen (Up):

Nitrogen is responsible for powering any leaf, stem, and foliage growth.

So, it represents the word up.

what is 12-4-8 fertilizer good for

To make things simple for you:

Nitrogen is the go-to nutrient for healthy, vibrant foliage, nurtures your grass (making it greener, thicker, and lusher), and supports essential functions like photosynthesis.

Now, let me introduce Phosphorus to you.

Phosphorus (Down):

We have 4% phosphorus in 12-4-8 fertilizer.

Phosphorus is the key to fruiting and blooms.

Phosphorus majorly supports plants’ shoot and root systems as well. Therefore, it represents the word down.

To make things simple, here’s how phosphorus is important for plants:

Phosphorus enhances the soil system and is vital for blooming and fruit production. The right amount of phosphorus means an improved root system, beautiful flowers, and more fruits.

Now, let’s jump straight to potassium.

Potassium (All-around):

Potassium boosts the health and development of your plant by building up its cells.

Potassium controls the flow of liquids and regulates the function of enzymes.

That’s why I say that potassium works “all around.”

Its ability to increase plants’ resistance to diseases makes it essential for plants. This, in turn, will make your plants strong and vibrant.

Plus, potassium will also improve your plant’s drought resistance by conserving moisture. Therefore, its deficiency will make your plants vulnerable to diseases.

That’s not what we want.

Potassium increases plants’ resistance to diseases. It improves the overall health of the plant by making them strong and vibrant.

With this, it is time to move on to our next topic.

What is 12-4-8 Fertilizer Good For?

As it contains all three macronutrients, the 12-4-8 NPK ratio is great for most plants.

For example:

  • Tomatoes
  • Peppers
  • Lettuce
  • Leafy vegetables such as Spinach and Broccoli

Let’s take a look at each of them in detail.

Plants That Like 12-4-8 Fertilizer:

Is 12-4-8 Good For Tomatoes?

Give nitrogen early to your tomatoes using the 12-4-8 fertilizer. When you start to see blooms, switch to a fertilizer with more phosphorus and calcium.

Giving nitrogen early is a great way to get your plant started.

So, the nitrogen in the 12-4-8 fertilizer will give a good start to your tomatoes until you start to see blooms.

When you start to see blooms, switch to a fertilizer with a higher middle number (phosphorus). For example, NPK 4-6-3, 5-10-5, or 5-10-10.

So, the simple advice of using nitrogen early on and later switching to more phosphorus and calcium works well.

What is 12-4-8 Fertilizer Good For?

However, a soil test is the most straightforward way to determine which nutrient your soil lacks. Then, you can decide what’s the best tomato fertilizer for you.

But you must apply the fertilizer according to the package instructions for the best results.



They do well with a steady nutrient profile and have similar nutritional requirements to tomatoes.

Similar to tomatoes, 12-4-8 fertilizer will give a good start early on with its nitrogen.

However, it is better to decrease that nitrogen percentage when flowering.

The rule is simple.

You will see fewer buds with too much nitrogen.

So, let me summarize this for you.

Tip For Peppers and Tomatoes: High nitrogen early, higher phosphorus, and high potassium late. I wouldn’t overthink it beyond that.

Just don’t overfertilize and expect good things to happen.


Leafy Vegetables:

Leafy vegetables mostly need more nitrogen for healthy growth and development.

The 12-4-8 fertilizer has plenty of nitrogen (12%) and provides other nutrients.

The high nitrogen is the key to generating healthy and green leaves. The potassium and phosphorous will also help establish the plant’s overall health.

So, the 12-4-8 NPK ratio is good for Broccoli, Spinach, Cabbage, and Lettuce as well.

Just fertilize according to the package instructions, and you are good to go.



Lawns generally love all three macronutrients to stay lush green.

what is 12-4-8 fertilizer good for

The nitrogen and phosphorus work together to give lawns a greener look while strengthening the roots.

The 12-4-8 fertilizer can transform your dull lawn into a lush green one if it’s low in nitrogen.

Just apply it according to the package instructions, and you are good to go.

However, it all depends on your soil condition. Perform a soil test to get personalized recommendations.

How To Apply 12-4-8 Fertilizer:

When it comes to the 12-4-8 fertilizer, you have two options:

Liquid or Granular.

12-4-8 fertilizer

Let’s take a look at each of them in detail.

Liquid Fertilizer:Granular Fertilizer:
Has to be applied more oftenLasts longer
Nutrients are instantaneously availableSlow-release
Application process is simple (watered in with the hose)Have to broadcast granules evenly

This takes us to the next point.

Best 12-4-8 Fertilizer:

Miracle-Gro Shake ‘N Feed Plant Fertilizer:

Not only does this fertilizer provide essential macronutrients, but it also provides important micronutrients, leading to stronger, more vibrant, and productive plants.

The best part?

It contains natural ingredients such as bone meal to feed microbes in the soil.

So, this product is a good choice for houseplants, flowers, and vegetables.

Miracle-Gro Shake 'N Feed All Purpose Plant Food

If you are looking for NPK 12-4-8, this one is for you!

Can I Use 12-4-8 Fertilizer for Hydrangeas?


Just like other plants, hydrangeas need nitrogen to kick-start their growth.

So, giving nitrogen early with 12-4-8 will give that crucial start to your hydrangeas.

Later on, when you want more buds, you must reduce that nitrogen percentage.

So, for more blooms, use a fertilizer formulated for hydrangeas, such as HollyTone (NPK is 4-3-4) or RoseTone.

You May Like:

When to Fertilize Hydrangeas in California For Beautiful Blooms

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Growing Hydrangeas in Texas | Step-by-Step Guide

This takes us to the next point.

Can I Use 12-4-8 Fertilizer For Dogwood Tree?

Quick answer: It can be a good all-purpose fertilizer.

12-4-8 fertilizer for dogwood trees

This means that it is helpful in the early stages and plays a good role in development.

  • At the start, you can use the 4-3-3 fertilizer for the best development in a short period.

Later, you can switch to the 12-4-8 fertilizer to fulfill the nutrient requirements.

Note that this will depend on the condition of your soil.

The plant will obtain macronutrients such as nitrogen, phosphorus, and potassium through this fertilizer.

  • The best time to fertilize the dogwood tree is in early spring.

At this stage, the tree has not grown flowers. The other application should take place in the summer.

Note that dogwood trees have to be fertilized regularly. Just make sure to read the instructions on the package carefully.

  • The fertilizer increases the blooming of the tree.

This is because the 12-4-8 fertilizer provides an excellent nutritional balance.

If I talk about application, 0.5 pounds of fertilizer per inch of trunk diameter should be added.

But this can vary as well.

The application should (generally) take place in March and July. Note that it should be applied along the drip line of your tree.

Now, let’s talk about tomatoes:

Can I Use 12-4-8 Fertilizer For Tomatoes:


As discussed earlier, give nitrogen early.

When you start to see blooms, switch to a fertilizer with a higher phosphorus, such as 8-32-16 and 6-24-24.

So, the simple advice is to give nitrogen early on and later switch to more phosphorus and calcium.

To know more about the frequency and rate of application, follow the instructions on the package.

Is 12-4-8 Fertilizer Good For Vegetables and Grass?

Let’s talk about vegetables first.


  • This high Nitrogen content makes it an excellent choice for vegetables.

We discussed the importance of nitrogen earlier as well.

The idea is that it is a good choice for some leafy and non-blooming plants.

  • Vegetables consume a lot of nutrients.

The idea is that vegetables obtain nutrients quickly from the soil. As you already know, this is a good all-purpose fertilizer.

This is the reason it is a good fit for vegetables. In other words, it provides lost nutrients to the plant.

Therefore, the plant grows in a better manner.

Is 12-4-8 Fertilizer Good For Vegetables

If I talk about its application, “healthy” soil should be fertilized every three to four weeks.

You should apply the fertilizer during the spring season. Over here, you should ensure it is correctly added to the soil.

Now, let’s talk about grass.


To be precise, it is a good fit for grass as the nutrients are in good proportion.

The high amount of Nitrogen will make your lawn grass greener and lusher.

Plus, phosphorus will help develop strong roots.

For mid-summer, dialing down nitrogen and phosphorus content can be crucial to prevent nitrogen burn.


Wrapping Up:

12-4-8 fertilizer can do wonders for your garden.

So, from all this discussion, we can say that this NPK ratio is great in the growing phase of plants, keeping them green and healthy.

So, what is this fertilizer good for?

NPK 12-4-8 is good for giving nitrogen early to plants such as tomatoes, peppers, leafy vegetables, and lettuce.

If you have more questions, feel free to get in touch. Stay tuned for more.

Happy Gardening!

Want to know about other NPK fertilizers? Check these out:

What is 6-6-6 Fertilizer Good For?

What is 20-20-20 Fertilizer Good For?

What is 18-24-12 Fertilizer Good For?

What is 34-0-0 Fertilizer Good For?

What is 18-18-18 Fertilizer Used For?

About Jayden Michael

Hey there! I’m a gardening enthusiast from Detroit, Michigan, and I have been gardening for over eight years. From growing a beautiful green lawn to nutritious vegetables, I’m excited to share all I’ve learned. So, let’s dig in and have some fun!

What is 12-4-8 Fertilizer Good For? | The Ultimate Guide

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