When Is 16-16-16 Fertilizer Best? | How to Use Triple 16

It’s not always easy to keep your lawn lush, flowers blooming, and your garden fruitful without fertilizer. Knowing what type to pick is almost like trying, especially with all the numbers involved. 

You may have a whole slew of questions and concerns, like when is 16-16-16 fertilizer best and how to use a triple 16 fertilizer. Let’s jump right in and decode those fertilizer labels now.

Understanding 16-16-16 Fertilizer Label?

Fertilizer labels display the percentage of nitrogen (N), phosphorus (P), and potassium (K) that they contain. A 16-16-16 NPK label means there is 16% each of nitrogen, phosphorus, and potassium and these basic elements are essential when it comes to improving soil and encouraging healthy plant growth. 

N-P-K Ratio

The three numbers found on the packaging of most fertilizers are known as the N-P-K ratio. These numbers differ from one fertilizer product to another depending on the needs and growing attributes of an individual plant. 

Here’s a closer look at why plants need these three vital macronutrients.


Plants rely on nitrogen for almost everything they need to survive and thrive, including their food and water supply. This macronutrient can give plants a rich, green color. Only three elements are more prevalent in plants than nitrogen. These are carbon, hydrogen, and oxygen.


Phosphorus supports plants by regulating the amount of protein a plant makes. While this obviously promotes growth and development, it focuses more on the roots and enduring winters. That said, phosphorus can help plants mature faster during the early stages of growth.


Plants need potassium to support growth, primarily by assisting with how water moves nutrients through the plant itself. It helps regulate intake to optimal levels for growth and develops starch levels while slowing how diseases advance through the plant tissue.

What Is Triple 16 Fertilizer Used For?

Triple 16 fertilizer, the common name for a 16-16-16 blend can be used on plants, trees, shrubs, vegetable gardens, flower beds, and lawns where a balanced mixture of nutrients is required to enrich the soil and help plants to thrive.  

Why Use a Balanced Fertilizer?

A balanced fertilizer is great if your soil is nutrient-rich and not lacking in any of the three vital macronutrients. It’s also perfect for vegetation that doesn’t require a specific boost of either nitrogen, phosphorous, or potassium. 

For example, lawns typically need additional nitrogen to enhance their vibrant, lush greenness. On the other hand, a fertilizer for tomatoes and other such vining fruits needs a higher dose of phosphorous to encourage the onset of buds and fruits.  

Balanced feeds such as 16-16-16, 10-10-10, or 20-20-20 fertilizer work well for container plants because these plants deplete the soil faster than those in the ground. 

Use a balanced fertilizer to help maintain soil pH and prevent a deficiency in either acidity or alkaline.

16-16-16 vs 14-14-14 Fertilizer

The only difference between a triple 16 and a triple 14 fertilizer is the concentration of nutrients in the blend. The higher the concentration percentage, the higher the dose of macronutrients that will get administered. 

Likewise, if your plants are thriving and need a gentle balance of NPK, opt for the lower concentration to avoid damage or over-fertilization. 

Fertilizer Type

Now that you understand what triple 16 fertilizer means, it’s time to decide the type you want to use. Each fertilizer type has advantages and disadvantages. It’s important to choose the one you feel the most comfortable handling. 

Liquid Concentrate

Liquid concentrates come in bottles, making it easy to store what you don’t use. You have to dilute the concentrate with water before applying it. Using a liquid concentrate requires a spray attachment for your hose or a watering jug.

There are a few advantages to using liquid concentrates. You get even application since every drop has the same amount of nutrients. Additionally, liquid concentrates are easy to use and work fast, so you should notice a difference within a few days. 

Unfortunately, because it releases and absorbs so quickly, the effects might only last for a few weeks up to a month, meaning you need to reapply it more frequently than other options. 

They are also prone to run-off when excess water is not absorbed. This can be potentially harmful to the environment, wildlife, and water sources if you are using an inorganic fertilizer that contains chemicals.

Liquid concentrates tend to cost more than some other options because of having to purchase them more frequently. 

Water-Soluble Powder

Water-soluble powders work much like liquid concentrates because you mix them in water and apply them the same way. 

The water-soluble powders can be more cost-effective than the liquids as you often get more concentrated powder, and it, therefore, lasts longer. 

Take care when using it and always follow the manufacturer’s instructions. For example, always wear a mask when pouring and mixing to avoid the potential for inhalation of dust particles.  

Slow-Release Granules

Slow-release granules are water-soluble, but they break down over time to gradually release the nutrients into the soil. Simply spread them over the desired area using a fertilizer spreader, water the area well and the granules will provide nutrients to the soil for several months. 

The benefits to using a slow-release granule include less chance of burning the vegetation than other soluble fertilizers, and the long-lasting effects mean fewer applications, typically one or two. 

While it might take a little longer to notice the impact, the effects typically last two to nine months. 

While the slow-release granules sound like the winning solution, be aware that there are a few drawbacks. First, the nutrients might not reach the roots as quickly. 

The other issue is that individual granules might have variable nutrient quantities as it’s not a homogenous mixture but a blend.

Fertilizer Spikes

Fertilizer spikes are an easy, highly convenient option, especially for small spaces. All you have to do is stick the spike into the wet soil. They work relatively fast, with results showing up in about a week. 

The downside to using fertilizer spikes is that they only work in a concentrated area, so they only benefit those roots closest to them and you need to use more of them for larger areas or mature trees and shrubs. 

You also have to space them carefully to avoid burning out the area. Typically, this will be about three feet apart, but always check your specific fertilizer for instructions.

How and When To Use Triple 16 Fertilizer

Triple 16 is a solid choice when you need an all-purpose, balanced fertilizer, especially if you have one of the more challenging soil types, like clay or sand. 

It’s generally safe for most vegetation and will help to establish a good root system and encourage healthy growth. 

Trees and Shrubs

Once established, a balanced feed will suffice as a suitable fertilizer for trees and shrubs. If mature plants exhibit deficiency – usually yellowing of leaves – use a high nitrogen fertilizer to improve the vibrancy and promote new growth. 

Fruit Trees

Fruit trees grown in planters notoriously drain nutrients quicker than those grown in the ground thanks to the regular leaching that occurs after watering. 

Use a balanced 16-16-16 NPK fertilizer to replenish those lost and depleted nutrients regularly. 


While a tripe 16 fertilizer will provide flowering plants with a balance of nutrients and some beautiful foliage, it may hinder a showstopping display of blooms. Use instead of a lower ratio of nitrogen such as a 5-10-10 fertilizer to get the most out of flowering shrubs and plants. 

The higher ratio of phosphorous and potassium to nitrogen will encourage bud development and resistance to disease. 

Vegetable Gardens

Using a triple 16 fertilizer at the start of the growing season, along with adding mulch and compost to the soil will help to add depleted nutrients to the soil that may have been lost during the previous year. 

When new growth begins, all vegetables will benefit from a boost of nitrogen, phosphorus, and potassium to establish roots, promote foliage growth and bud set. Indeed, many vegetable plants do perfectly well with a balanced NPK fertilizer such as 16-16-16, especially at the start of the growing season.  

Bear in mind that you should opt for a specific fertilizer for pumpkins, tomatoes, and other vining plants. These need a higher ratio of phosphorus and potassium as the season progresses. This helps with the all-important bud onset and development of large and plentiful fruits come harvest time. 


Houseplants can be trickier than their outdoor counterparts. Typically, houseplants live in smaller containers meaning that any fertilizer would be more concentrated in the space. While a triple 16 fertilizer should work for some hardier houseplants, it might be too much for more delicate varieties. 

For houseplants, it’s important to follow the directions for each species to ensure you give them the best soil conditions possible. However, if you like the idea of one fertilizer for everything, you could use a 12-12-12 fertilizer or dilute a 19-19-19 fertilizer to weaken it.  

Lawn and Grass

Triple 16 fertilizer can support lawn growth and make the grass greener. While this is a great fertilizer for all-around plant health, especially if you can’t get your soil tested, it isn’t the absolute best for grass as lawns don’t need as much phosphorous as blooming plants.

Instead, consider using a high nitrogen liquid lawn fertilizer that will provide you with and greenest and most vibrant turf.

Final Thoughts

Choosing the best fertilizer for your yard can be challenging, especially with so many brands clamoring for your money. Doing a little research in advance can save you a lot of time and money in the long run. 

Now you know that a 16-16-16 fertilizer is a balanced blend that works for most vegetation. If you only have a few flowers, shrubs, or trees and a large lawn, this fertilizer might not be the optimal choice. 

However, if you have a little bit of everything, including some already nutrient-rich soil, a triple 16 fertilizer could save you a lot of time and money.

16-16-16 Fertilizer FAQs