What Is 18-18-18 Fertilizer Used For?

Learn everything you need to know about the 18-18-18 fertilizer, from its nutrient contents and NPK ratio to its benefits and spread rate.

Sean Stratton | Updated December 28, 2022
hands full of 18-18-18 fertilizer

The 18-18-18 fertilizer has a unique NPK ratio that is suitable for a wide variety of plants. For a beginner who has never heard of an 18-18-18 fertilizer, it’s normal to come up with questions like what is an 18-18-18 fertilizer or what is 18-18-18 fertilizer used for, and so on.

That’s why in this guide, we are going to talk about 18-18-18 fertilizer. But to give you an overview of what it is and what it is used for, I will say: 18-18-18 fertilizer is a water-soluble or granular fertilizer that contains an equal amount of Nitrogen (18%), Phosphorus (18%), and Potassium (18%). It is used for vegetables, fruit trees, flowers, and ornamentals.

Now let’s jump into the main topic of our discussion and explain more facts about 18-18-18 fertilizer in a bit more detail.

Important Read: Top Fertilizers for Growing Huge Cucumbers

What Is 18-18-18 Fertilizer Used For?

18-18-18 fertilizer can be used on different plants. This fertilizer works on vegetables, fruit trees, flowers, and ornamentals. You can use this 18-18-18 fertilizer on fruit trees like Citrus. This fertilizer is also suitable for vegetables like eggplant, sugar beets, tomato, potato, and pepper, plus all types of leafy vegetables.

For field crops like cotton, this one is a great choice. If you have a fruit garden, you can use 18-18-18 fertilizer on your grape trees, melon, squash, and watermelon. Nevertheless, you can apply this fertilizer to your flowers and indoor plants.

Since many brands offer water-soluble 18-18-18 fertilizer, you can use it for soil and foliar in both applications. Being a water-soluble fertilizer, you don’t need to go through all that hassle while applying it. This fertilizer is recommended for fruit trees and vegetables that are in the fruiting stages.

However, some fertilizer brands even assure that you can use their 18-18-18 fertilizer during the whole plant growth cycle. If that makes you confused, you can apply the fertilizer according to the instructions provided by the manufacturer of the fertilizer you chose.

The 18-18-18 fertilizer has a balanced ratio of nitrogen, phosphorus, and potassium. So, if you can apply the fertilizer properly, these vital nutrients and the additional nutrients will help your plants achieve healthy leaves, branches, a better root system, and overall improved health.

The Nutrients in 18-18-18 Fertilizer

The number 18-18-18 in the fertilizer is indicating the NPK ratio of the fertilizer. The NPK ratio shows the percentage of nitrogen, phosphorus, and potassium in the fertilizer. So, from this fertilizer, your plants will get these three vital nutrients.

Not only those, but the fertilizer can also contain nutrients like iron, zinc, boron, copper, molybdenum, and so on. Additionally, compounds like Ammoniacal nitrogen (NH4), Magnesium oxide (MgO), Nitric nitrogen (NO3), Sulfur trioxide (SO3), and more can be present in an 18-18-18 fertilizer.

The N-P-K Ratio of 18 18 18 Fertilizer

18-18-18 fertilizer contains an equal amount of nitrogen, phosphorus, and potassium. The number 18-18-18 shows the percentage of nitrogen, phosphorus, and potassium respectively. Plants receive significant nutrition from equal amounts of three essential nutrients.

18-18-18 provides your trees, vegetables, and flowers with the essential nutrients for proper and balanced growth, a better root system, and healthy stems and branches.

The nutrients in the fertilizer help the plants to be strong enough to withstand adverse conditions. The nutrients can also contribute to a bountiful harvest if applied properly.

Is 18 18 18 Fertilizer Good for Lawns?

The 18-18-18 fertilizer contains a unique NPK ratio. It contains some essential nutrients that can help your grass thrive and result in a lush green lawn. However, that doesn’t mean we can apply it anywhere. When it comes to grass, you need to ensure the right amount of nutrients.

If the provided nutrients are less than required, your grass will simply not thrive as expected. And if the nutrients are way too much, your lawn can be damaged badly. That’s why before applying any fertilizer to your grass, first test the soil and check which nutrients the soil is lacking.

After soil testing, check the information panel of your selected fertilizer packet. If the manufacturer recommends using it on grass and the NPK ratio fulfills the needs of the soil, you are good to go with it.

18-18-18 Fertilizer Spread Rate

The application rate of fertilizer depends on the formula. It is also dependent on the plant’s nutrient requirements. However, the formula, type of fertilizer, etc. vary from brand to brand.

For example, Shur-Crop 18-18-18 fertilizer comes in granular form and a 50 lb (22.68 kg) bag is enough to cover an 8,000 sq. ft. area. This makes it clear that the spread rate will be different from other types of fertilizer. So, to identify the spread rate of the brand you choose, check the information on the package or trusted sources of that brand.

Frequently Asked Questions

Will 18-18-18 Fertilizer Help Plants Grow Properly?

Fertilizers are made to help your plants one way or the other. This is the primary objective of any fertilizer. That’s why 18-18-18 fertilizer is not an exception. As we have said many times, 18-18-18 fertilizer contains many essential nutrients for your plants, including nitrogen, phosphorus, potassium, and so on.

Every plant needs these more or less. So, when you apply the 18-18-18 fertilizer, the nutrients will start resolving the deficiency issues and work on improving the soil so that the plant can get the needed nutrition and grow properly.

Is 18-18-18 Fertilizer Good for Lemon Trees?

Lemon trees require high nitrogen. So, the fertilizer should be one with a high nitrogen ratio. However, there is a limit to the nitrogen ratio. The NPK ratio of an ideal fertilizer should not exceed 8-8-8. An example of a good lemon fertilizer would be 6-6-6 fertilizer.

Since we are talking about 18-18-18 fertilizer, we should understand that the 18-18-18 NPK ratio is way beyond the 8-8-8 limit. However, some brands suggest their 18-18-18 fertilizer is good for fruit trees like Citrus. You may check those out for additional information.

Final Thoughts

To grow healthy and produce better harvests, your plants need fertilizer. Depending on the nutrient content of the fertilizer, plants can benefit differently from different fertilizers. In this article, we talked about 18-18-18 fertilizer and what are its uses.

If your plants lack specific nutrients, and you find out that 18-18-18 fertilizer is the remedy, follow our information and wait to see the results.

Written by Sean Stratton

Sean Stratton

Hi, I'm Sean, the senior editor here at Fertilizer Pick. I grew up on a farm in North Carolina and have grown fruits, vegetables, and trees since childhood. While I no longer live on a farm today, I still enjoy spending time on my garden and sharing my knowledge with friends and fellow garden enthusiasts.