8-32-16 Fertilizer For Tomatoes | Is It The Best?

Tomatoes are heavy feeders and need more nutrients to thrive. So they love fertilizers that enhance their growth.

We use different fertilizers at different stages to get great-tasting tomatoes.

So, can I use 8-32-16 fertilizer for tomatoes?

Here are all my top tips from planting to harvest. Let’s get straight into it.

What Does “8-32-16” Mean?

As the name suggests, this fertilizer has an NPK ratio of 8-32-16.

Well, what’s that?

This shows the percentage of nitrogen (N), phosphorus (P), and potassium (K) in the fertilizer.

So, the 8-32-16 fertilizer contains the following:

  • Nitrogen: 8%
  • Phosphorus: 32%
  • Potassium: 16%

Now, let’s find out why these nutrients are essential for tomatoes.

What Does “8-32-16” Mean


According to the University of Missouri Extension, tomatoes need nitrogen for optimal growth and development.

Plants use chlorophyll, a nitrogen compound, to create sugars through photosynthesis.

Nitrogen makes amino acids, proteins, nucleic acid, and DNA (deoxyribonucleic acid).

Pretty crucial for tomatoes.

If your soil does not have enough nitrogen, tomatoes will appear stunted with a yellowish cast to the leaves. However, too much nitrogen can cause blossom end rot in tomatoes. Therefore, tomatoes need enough nitrogen for thick vines (to support the fruit).

Now, let’s talk about phosphorus.


Phosphorus plays a crucial role in the growth and development of tomatoes.

The right amount of phosphorus will ensure a healthy fruit set.

Tomatoes need phosphorus in large amounts before flowering and fruiting.

A phosphorus deficiency during these stages significantly impacts the fruit, leading to decreased growth and delayed ripening.

Some other prominent functions of phosphorus are:

  • Energy transfer
  • Photosynthesis
  • Movement of nutrients
  • Transformation of sugar and starch

Phosphorus is essential for tomatoes as it encourages healthy root development. The right amount ensures a juicy and bountiful crop.

Now, let’s talk about potassium.


As I mentioned earlier, there is 16% potassium (K) in the 8-32-16 fertilizer.

You should know that tomatoes need lots of potassium. However, too much can lead to nitrogen deficiency.

Potassium is vital as it is crucial in facilitating the transport of nutrients, water, and carbohydrates.

This is why potassium enhances the juiciness and sweetness of your tomatoes.

In short, potassium controls the flow of liquids and regulates the enzyme functions in tomatoes. Therefore, it is essential during the flowering stage.

This takes us straight to our next topic.

Can I Use 8-32-16 Fertilizer For Tomatoes?


Tomatoes are heavy feeders and like fertilization at different times with different products.

Remember that using the right product at the right time will lead to healthy growth and fruit development.

The 8-32-16 fertilizer is excellent for tomatoes around two weeks before flowering. The high phosphorus content will boost the flowering process at this pre-flowering stage, generating more and better quality fruit.

8-32-16 Fertilizer For Tomatoes

Let me explain this in detail.

We are going to fertilize our tomato plant in just four simple steps.

Step 1: Before Transplanting

Some gardeners like to add bone meal before transplanting.

However, there is a problem.

A boost of nutrients at this stage can lead to transplant shock. Therefore, I recommend you avoid fertilization at this stage.

Add compost or aged manure to your tomato plant’s intended spot. This will add nitrogen to the soil that your tomato plant will need.

Now that the soil is ready to welcome the tomato plant, it is time for the first application.

Step 2: First Application

After the plant has been in the ground for 2-3 weeks, it is time for its first fertilization.

Fertilization is essential because the plant has established its root system by this time, and fertilization will boost its growth significantly.


At this stage, your tomato plant needs a fertilizer high in nitrogen. I use a balanced 10-10-10 fertilizer according to my soil needs.

If your soil is a bit low in nitrogen, you can go with NPK 20-10-10 fertilizer. Therefore, I highly recommend you do a soil test.

Note: The 8-32-16 fertilizer should not be used at this stage.

Also, add the fertilizer according to the instructions on the package.

Step 3: Before Flowering:

The second fertilizer application will take place around two weeks before the tomato plant flowers.

A fertilizer high in phosphorus is what your tomato plant needs for growth and development.

Based on my experience, the 8-32-16 fertilizer has proven to be the most effective.

At this pre-flowering stage, the high phosphorus in the fertilizer will boost the flowering process, generating more and better quality fruit.

Step 4: Before Fruiting:

This fertilizer application will occur as the plant starts fruiting.

This is because fertilization at this stage will provide a nutrient boost for bigger and better fruits.

Now the main question is, what fertilizer to use?

A fertilizer with high potassium content is needed at this stage. Therefore, a fertilizer such as the 10-20-20 or 6-24-24 is recommended.

I do not fertilize when the plants start to fruit heavily. So, here’s the summary.

When to fertilize:What fertilizer to use?
1. Before transplantingAdd compost or aged manure to your tomato plant’s intended spot.
2. Once the plant has been in the ground for 2-3 weeksUse a nitrogen-rich fertilizer, such as the 10-10-10 or 20-10-10 fertilizer.
3. Before floweringUse a fertilizer high in phosphorus, such as the 8-32-16 fertilizer.
4. Before fruitingUse a fertilizer high in potassium, such as the 6-24-24 fertilizer.

When Not To Fertilize Tomatoes:

We know tomatoes are heavy feeders, but they must not be overfertilized.

Overfertilization can lead to many problems, such as burning, and can cause your tomato plant to die.

When Not To Fertilize Tomatoes

So when not to fertilize tomatoes?

If the soil already has sufficient nutrients:

In the beginning, if the soil has plenty of nitrogen, avoid providing too much nitrogen, as it can burn your plant.

A soil test is great before planting as it shows your soil’s current condition, which will help you take the necessary measures.

So if your soil has plenty of phosphorus and potassium at the flowering and fruiting stages, avoid using fertilizers such as 8-32-16 or 6-24-24.

During early stages of growth:

As mentioned before, shortly after the planting process, the tomato plant does not need any fertilization.

This is because the plant needs time to adjust to the new surroundings.

So, avoid using any synthetic fertilizer. Instead, use compost or manure to provide necessary nutrients and retain the soil’s moisture.

This takes us straight to our point!

During drought:

During periods of drought, there is little water for the plants to absorb, and fertilization can worsen the situation.

Fertilization during a drought can strain the ability of the plant to absorb nutrients as they are under tremendous stress due to the lack of water.

This can cause damage. So, it is best to avoid fertilization at this stage.

During the late season:

During the late season, the tomato plant begins to ripen and grow fruit. So, fertilization can disturb this.

You may ask how?

When the plant is ripe and starts to produce fruit, fertilization can stimulate the growth of leaves.

This leaf growth will occur instead of fruit production and absorb its nutrients.

In short, fertilizing at this stage can cause problems with the fruit quality.

You May Like:

Is Mushroom Compost Good For Tomatoes?

Banana Peel Fertilizer | When To Use It?

Bone Meal Fertilizer | When To Use It?

Now, to our next point!

FAQs About Fertilizing Tomatoes:

Here are some popular questions regarding fertilizing tomatoes. Let me answer them for you.

Can I use bone meal fertilizer for tomatoes?

Bone meal is an excellent choice for tomato plants in every stage of their growth and development.

Let me break this down for you.

Before Planting:

Bone meal is an excellent source of nitrogen and phosphorus for the seedling to grow and develop.

In the beginning, the nitrogen and phosphorus boost will develop a solid and healthy root structure, which will help the plant in the longer run.

If I talk about the application rate, apply 1 cup of fertilizer for every 10 square feet of soil. Similarly, you can also apply bone meal fertilizer at the time of planting as well.

Just apply a small amount at the bottom of the hole you dug.


During growth:

Applying bone meal to the base of the plant during early growth (when the plant starts to develop leaves and stems) is also a good idea.

The phosphorus in the bone meal is essential as it encourages more flowers to grow later, producing more fruit.

Watering after fertilization is essential to ensure proper nutrient uptake.

The bone meal is also effective during the fruiting stage. The application process will be the same.

This takes us straight to our next point!

What Fertilizer Ratio Is Best For Tomatoes:

We know that tomatoes at different stages need different nutrients.

So let’s break down the best fertilizer at every stage so you can grow the best tomatoes in the town.

Before Planting:

We know that in the start, tomatoes need little nitrogen and phosphorus to grow healthy.

So at this stage, the best choice you be to apply the bone meal fertilizer.

During Planting:

The seedlings need sufficient nitrogen to develop healthy and solid roots.

So after planting the seedling, we will cover the soil with compost or manure.

8-32-16 fertilizer for tomatoes

The compost will give the seedling nitrogen and moisten the soil for the best growth.

Early Growth:

When the plant develops leaves and stems, it is time to apply the bone meal fertilizer again.

The plant at this crucial stage needs phosphorus which the bone meal fertilizer will ideally provide.

Pre-Flowering Stage:

When the tomato plant shows signs of flower growth, it needs a lot of phosphorus at this stage.

So the best fertilizer choice at this stage would be the 8-32-16 fertilizer.

The fertilizer will increase the flower growth, later increasing fruit growth.

Fruiting Stage:

When the tomato plant starts to fruit, it demands more potassium.

So at this stage, the best choice would be to apply 6-24-24 fertilizer.

This fertilizer has high potassium and phosphorus and is an excellent choice for the best fruit development.

Can I Use 8-32-16 Fertilizer For Corn:

Yes! 8-32-16 fertilizer can be used for corn at a particular stage.

Can I Use 8-32-16 Fertilizer For Corn

In the early stages of corn development, it needs more nitrogen, so a fertilizer with high nitrogen should be used.

However, when the corn plant has 6-8 leaves, it needs more potassium. So, the 8-32-16 is an excellent choice.

During the late season, it again needs more nitrogen, so a fertilizer like urea can be used (46-0-0).

You should be careful, as too much nitrogen will do more harm than good.

Final Verdict:

So there you have it.

Is the 8-32-16 fertilizer good for tomatoes?

I like to use this fertilizer before flowering due to its high phosphorus content. As I mentioned earlier, different fertilizers should be used at different stages.

Simply adding compost or aged manure will do the job just before transplanting. Before fruiting, a fertilizer high in potassium (6-24-24) is recommended.

Remember that it is always a good idea to conduct a soil test. In this way, you can get personalized recommendations.

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

8-32-16 Fertilizer For Tomatoes | Is It The Best?

Leave a Reply

Your email address will not be published. Required fields are marked *

Scroll to top