Whether you are growing fruits in your backyard garden or crops on a commercial farm, plants need vitamins and minerals to thrive. Sadly, they do not get enough from water alone. To ensure healthy growth, they need essential nutrients, which they can get through fertilizers.

Fertilizers will supply the macronutrients that are crucial for the survival of plants. Among others, the most important are nitrogen, phosphorus, and potassium. This is a trio known as NPK. Plants need them in large quantities, which is why they are common in fertilizers that you will find in the market.

While you will have countless options for fertilizers, one of the most popular is a 13-13-13 fertilizer, which is what we will be talking about in this short guide.

We’ll give you a quick look at what it is, and we’ll also teach you the right and wrong way of using this fertilizer. Especially if you are new to gardening and fertilizers, we are here to extend a helping hand.

So, What Does a 13-13-13 Fertilizer Mean?

The number in the name refers to the percentage of the three main chemicals that you will find in a common fertilizer. This means that a triple 13 fertilizer comes with 13% nitrogen, 13% phosphorus, and 13% potassium.

It is a general-purpose and quick-release product, which needs frequent application to obtain optimal benefits. The frequency of its application, however, will depend on what the manufacturer recommends.

It is not enough to know what the numbers mean. It is also important that you understand what the specific components can do to your plants. Below, let us have a closer look at the three main nutrients you will find in a fertilizer.


About 78% of the atmosphere is made of nitrogen. In the same way that nitrogen is important for humans to breathe, it is also crucial for plants to survive.

Nitrogen is a chemical that is responsible for vegetative growth. It allows foliage or leaves to grow. It also assists in the growth of branches and stems.

One of the most obvious indications that your plants lack nitrogen is when it is stunted. Having yellowing leaves is also a sign of the need for more oxygen.


This is another essential chemical in the growth of plants. Its functions cannot be replaced by any other nutrient, so make sure that your plant receives an adequate supply of phosphorus.

To maintain the health and vigor of plants, supply them with the nutrients they need. Phosphorus will be helpful when it comes to stimulating root development, improving flower formation, increasing seed production, and enhancing resistance.

When a plant is deficient with phosphorus, it often does not display any immediate symptom. This makes it difficult to determine if you need to add more of this chemical in your fertilizer or not.


Especially in changing weather conditions, potassium is another chemical that plants need. It will improve their tolerance to external conditions, such as heat and snow. This will also protect the plants from a wide array of diseases.

From photosynthesis to protein formation, potassium is beneficial in more ways than one. It will regulate the opening and closing of stomata, which is important for the regulation of carbon dioxide.
If you are growing fruits and veggies, potassium is also important. It will encourage bigger crop production.

Our Top Picks for the Best 13-13-13 Fertilizer

Clueless about the right fertilizer to buy? Below are some of the top products that should be on your list.

Dynamite 887746 Flowers and Vegetables Plant Food

Specifically formulated for flowers, vegetables, and citrus blooms, applying this 13-13-13 fertilizer is believed to be highly effective in increasing yield. It will let you grow bigger and beautiful crops!

Aside from nitrogen, phosphorus, and potassium, it contains other essential minerals that will help plants to stay healthy. Its list of ingredients also includes magnesium, sulfur, iron, and manganese.

One of the best things about this product is its ease of use since you can apply it directly to the plant that you wish to fertilize. All that you need to do is give the bottle a quick shake, apply near the roots, and water the plant.

Lastly, it is also well-loved because it provides the best bang for the buck. It is packaged in a 2-pound container, which you can use continuously for up to nine months.

Carl Pool Controlled Release 13-13-13 Fertilizer

With the scientific formulation of this triple 13 fertilizer, you can be confident that it will provide the essential nutrients for the growth of your plant.

Before using this product, take note that this is a granular fertilizer. This means that it has a slow-release mechanism. This is against a water-soluble fertilizer, which will be quicker.

One pack of this fertilizer is good for up to four months of use. This, however, will depend on the conditions, such as the plant that you have and your specific goal for using a fertilizer.

Pendelton Turf Supply 13-13-13 Garden Grower Fertilizer

Using this perfectly-balanced fertilizer will make you more confident that your plants will grow. It can be used in blackberries, apples, brussels sprouts, sweet corn, onions, potatoes, green beans, peas, eggplant, radishes, tomatoes, and carrots, among others.

The specific mixture of the fertilizer needed will depend on a specific application. For instance, if you will be using it for garden plants, you will need .5-pound for every row of 25 feet.

How to Use Triple 13 Fertilizer Properly

Learning the proper way of applying 13-13-13 fertilizer is one of the secrets in unleashing its full benefits. While these fertilizers are promising, the outcomes will depend on how you use it.

One of the most common types of a triple 13 garden fertilizer is one in granular form. It delivers food slowly to the plants and is known for its longevity. There are two main ways of applying this fertilizer:

  • Broadcast Application: It is a method of spreading fertilizers uniformly. It is a common choice in large applications, such as in agricultural lands. This is done with the use of equipment like fertilizer spreaders.
  • Top-Dress Application: In contrast to a broadcast application, this method will require the administration of fertilizers by hand. You will concentrate the application around the base of the plant to the drip line.

You will also find triple 13 water-soluble fertilizers. As the name implies, they will dissolve in water and will be quick for the plants to absorb. While they are fast-acting, the drawback is that you need to apply the product frequently.

  • Base Application: You will be using a hose or a can for watering plants with fertilizers. It is directly applied to the base, which will allow quick absorption of the fertilizer.
  • Foliar Application: Instead of applying the fertilizer to the base or roots, you will apply it to the leaves. This is important for the quick absorption of necessary trace minerals, such as iron.

When applying 13-13-13 fertilizer, another important consideration will be timing. This can make the difference between success and failure. Do not think that you can apply it just at any given time.

For most perennials and annuals, the best practice is to fertilize in early spring. If the spring showers have already started, it is no longer a good idea to fertilize. You will end up wasting money because the chemicals in the fertilizer will only leech on the soil.

To maximize the benefits of the fertilizers, go beyond nitrogen, phosphorus, and potassium. Look for additional nutrients, such as calcium, magnesium, and sulfur. Micronutrients like boron, copper, iron, and zinc will also be important.

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Mistakes to Avoid when Using a Fertilizer

Make the most out of the triple 13 fertilizer that you are using. Make sure that you do not commit the mistakes listed below.

  • Do not apply the same fertilizer in all plants. While they can provide the nutrients that soil and plants need, take note that there is no onesize-fits-all approach. Luckily, most labels are pretty much clear with the recommendations on the specific plants where you can apply the fertilizer.
  • Do not apply the fertilizer without testing the soil. You need to first evaluate the nutrients that are lacking. You need to calculate the exact requirements to ensure the maximum effectiveness of the product you will be using.
  • Do not apply more than what is necessary. You will not just end up wasting money, but it can also do more harm than good to your plants. Over-feeding can just be as harmful as under-feeding. So, determine the exact requirements and follow the recommendations of the manufacturer.


In sum, a 13-13-13 fertilizer simply means that the fertilizer has 13% each of nitrogen, phosphorus, and potassium, which are three of the most important chemicals that plants need. While these are the most important, they might not be enough. Research what your plants need to have a better idea of the fertilizers that can optimize growth, especially in terms of crop yields and defense against diseases.

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