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What is 18-18-18 Fertilizer Used for — Growgardener Blog

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Hello fellas! looking for some professional content regarding the use of balanced fertilizers? Wanna know what is 18-18-18 fertilizer used for? We’ve got this amazing article just for you, enjoy!

Fertilizers are natural or synthetic materials having chemical elements to improve the growth and production of plants so that they thrive at their maximum peak. They enhance the soil’s natural fertility, which ultimately increases crop production.

Fertilizers act as food for the plants, providing essential nutrients.

There are two types of fertilizers named organic and inorganic:

Organic fertilizers are either the end products or by-products of naturally occurring substances such as manure and compost. In contrast, inorganic fertilizers are artificial ones and are synthesized in laboratories.

The 18-18-18 fertilizer is a chelated, crystalline, inorganic fertilizer that is suitable for all soil types. It is named 18-18-18 fertilizer because it contains a balanced concentration of NPK — 18% nitrogen, 18% phosphorous, and 18% water-soluble potassium.

Polyamix 18 18 18 fertilizer. What is 18 18 18 Fertilizer Used for
“What is 18-18-18 Fertilizer Used for?” — Polyamix Fertilizer via Anorel.

Today, we’ll go through what is 18-18-18 fertilizer used for, some of its benefits, and the effects of overusing it. So, if you are wandering in search of this topic, you jumped at the right spot!

Let’s get straight into it.

What is an 18-18-18 Fertilizer?

18-18-18 fertilizer is NPK fertilizer in the form of white granules and contains high nitrogen, phosphorous, and water-soluble potassium concentrations. These elements have an essential role in plant regulation:

  • Nitrogen (N) combined with carbohydrates in the cell wall is a part of the energy system. It involves the synthesis of vitamins and auxins.
  • Phosphorous (P) transfers energy to the whole plant, is vital in seed formation, and stimulates root growth.
  • Potassium (K) is an activator of many central enzymes, such as protein synthesis and photosynthesis. It is also essential for ensuring optimal plant growth.

18-18-18 contains all primary elements in a 1-1-1 ratio — as in 19-19-19 or 20-20-20 NPK fertilizers.

Primarily used for matured plants, it provides the necessary nutrients for balanced growth during the complete growth cycle. It is full of nutrients and doesn’t go really well mixing with mineral oils and alkaline products.

Its most incredible feature is its ability to dissolve easily in water. Therefore, you can directly apply it to the soil using drip, sprinkler, and other irrigation systems.

What is 18-18-18 Fertilizer Used for?

So, What is 18-18-18 fertilizer used for? By now, you might have got some understanding, but let me elaborate it a little further.

18-18-18 is a foliar fertilizer usually recommended during the fruiting stages of fruit trees, vegetables, and flowers (during the blooming season). You can use 18-18-18 fertilizer for all types of crops, but mainly, it is used for tomatoes, melons, leafy vegetables, citrus fruits, etc.

Generally, it enhances the root systems of your green buddies during their growing stage. It also stimulates blooming. Its chloride-free formula is the best combination to improve and increase nutrient absorption, especially during critical moments.

Application Guide for 18-18-18 Fertilizer

Every plant requires fertilizer in a certain amount for its proper and healthier growth. Suppose you fertilized your plant without knowing the correct amount. In that case, it may harm your crop rather than flourishing it.

Here I will guide you with the right amount of fertilizer to use for some common crops.

Cotton Crop

  • You can apply 18-18-18 fertilizer to cotton crops during leaf development.
  • You can also fertilize the crop 3–4 times with 15 to 20 days of recess during the formation of side shoots and the flowering period.


  • Apply 18-18-18 fertilizer to the potato crop during the emergence of shoots from the soil.
  • Continue to fertilize the crop after the tuber has formed in the soil.


  • Apply this fertilizer thirty days after transplanting your veggies.
  • During the growing season 4 to 5 times, repeat the process with a 10 to 15 days gap.

Fruit Trees

  • You can smear the fertilizer before bloom and after the fruit set.
  • You can also apply fertilizer on fruit trees whenever you feel it essential to support fruit growth but be careful not to overfertilize.

Indoor Plants

  • In the case of indoor plants, apply fertilizer in the form of a foliar spray or dilute the fertilizer in the irrigation water.
  • You can apply fertilizer to your indoor plants during all growth stages with an interval of 15 days.
NPK Fertilizer for Plant Application in Gardening? How Much and How to Use | English – YouTube

Benefits of Using 18-18-18 Fertilizer

18-18-18 fertilizer ensures the best development of your harvest.

  • Balanced fertilizers enhance the internal and external quality of fruits, vegetables, and flowers.
  • These types of fertilizers also improve the health of your plants and effectively prevent them from nutrient deficiency, especially under stressful growth conditions
  • As I mentioned above, 18-18-18 is a balanced fertilizer and can quickly meet the crop’s needs. Using these nutrient-rich fertilizers during the intensive growth stages ensures the optimal development of plants, roots, and flowers.
  • Fertilization is usually advised during the growing period, but it is helpful in all stages of crops.
  • 18-18-18 fertilizer is in a particular project to be applied via fertigation.

Fertigation is an application of plant nutrients through the irrigation system. In this process, plant roots receive water and nutrients simultaneously at the same place.

Related Article: Best Organic Lawn Fertilizers.

Effects of Overusing 18-18-18 Fertilizer

The overuse of all the inorganic fertilizers causes soil, air, or water pollution by nutrients espousing and destroying the soil, or leaching out and going into the water channels.

On a higher level, it can result in alarming environmental problems.

Like other inorganic fertilizers, 18-18-18 fertilizer — when leached from the soil into the water, causes water pollution. Prolonged use of NPK fertilizers causes a decrease in soil’s nutrient density and increases soil porosity.

  • These fertilizers further block the uptake of micro-nutrients and encourage the attack from harmful pests.
  • In indoor gardening, overfertilization increases the number of minerals and salts in the soil.
  • Excessive nitrogen in fertilizers takes water away from the plant and leaves behind only salts. In that case, leaves show a burnt look due to dehydration.
  • Leaves start to wilt, and their edges turn yellow or brown.
  • Excess fertilizer can also lead to the burning of roots and can result in the death of your plant.
Brown edges on a leaf. — What is 18 18 18 Fertilizer Used for?
“What is 18-18-18 Fertilizer Used for?” — Image via Truecolors.


With all that said, let’s conclude the talk here. I hope you got your answer to “What is 18-18-18 fertilizer used for?”

A quick summary:

  • We saw what is 18-18-18 fertilizer used for.
  • Fertilizer is an essential material used mainly for a plant’s better growth and increases the productivity of crops.
  • There are many fertilizers synthesized artificially, and NPK 18-18-18 fertilizer is one of them.
  • The 18-18-18 fertilizer contains all the primary elements essential for plant growth. Always use fertilizers in a proper way as mentioned above — application of 18-18-18 fertilizer for different crops.
  • But as the excess of everything is bad. You have to use these fertilizers in the required amount. Excess usage causes more harm than good to your plant by burning leaves and blocking the uptake of water and nutrients after root burn.

If you found this article helpful, consider sharing it with your friends and family.

Happy Planting!

Regards, Moiz Atiq.