What is 20-20-20 Fertilizer Used For? – When and How to Use It?

Choosing a fertilizer doesn’t have to be difficult. This guide will explain everything you need to know about 20-20-20 fertilizer so you can decide if it is the right fertilizer for your plants. 

What Is 20-20-20 Fertilizer?   

Triple 20 fertilizer has twenty percent nitrogen, twenty percent phosphorous, and twenty percent potassium. The numbers on the front of the fertilizer bag are explained in more detail in this article.   

Briefly, nitrogen is used in every part of the plant, so all plants need lots of nitrogen. Otherwise, they are stunted, have few or no blooms, and may die. Phosphorous triggers blooms and fruit in plants. It is also involved in converting the energy in sunlight into compounds such as starches, proteins, and oils that the plant uses for energy. Potassium builds strong roots and vigorous plants that resist diseases. It is also involved in the circulation of nutrients throughout the plant.  

What Is 20-20-20 Fertilizer Used For?   

It is used primarily in fertilizing potted plants, roses, and other ornamental plants as a liquid. I have not found a slow-release form of this fertilizer.  

Why Use 20-20-20?  

Triple 20 fertilizer is a strong fertilizer that quickly adds nutrients to potted plants and outside ornamental plants so that the plants can grow well. However, it is strong and should not be used in fertile soil outdoors as you may add too much nitrogen, phosphorus, and potassium. Too many of these nutrients can cause your plant to put on foliage at the expense of blooms. In some cases, too many of these nutrients can kill your plants. Triple 20 is not an all-purpose fertilizer and may be too strong for some sensitive plants.  

Types of 20-20-20 Fertilizer  

Triple 20 fertilizer comes in several forms. Here is what they are and what they are used for.  

Liquid Fertilizer  

Liquid fertilizer comes in two forms. Ready-to-use fertilizer comes already mixed and ready to apply to the plants. Concentrates have to be mixed with water before being applied. Concentrates are more expensive initially but provide more fertilizer when mixed. Liquid fertilizer is immediately available to plants but needs to be reapplied frequently. The soil around the plant should be drenched with a liquid fertilizer when it is applied. Some triple 20 fertilizers can be used as foliar sprays. 

Water Soluble Fertilizer   

Triple 20 water-soluble fertilizer comes as granules or a powder that is mixed with water and applied as a liquid to plants. A hose-end sprayer is a popular way to dilute and apply these products, but they may be mixed in a bucket and poured around the plants.  

Fertilizer for Hydroponics  

Hydroponics is a way of growing without soil that delivers all nutrients in a water solution. A liquid or water-soluble triple 20 will work for a hydroponic solution.  

Granular Fertilizer  

Granular fertilizer is a solid fertilizer that is made into small granules. Most granular fertilizers are spread around the plant, and then the plant is watered. Some granules are water-soluble and are mixed with water before being applied. All of the granular triple 20 fertilizers I have found are water-soluble, so are mixed with water to use. 

Organic Fertilizer  

Organic triple 20 fertilizer has only natural ingredients allowed in organic gardening. In addition, the manufacturer has gone through the process to have the fertilizer certified as organic through the USDA or another organic certification agency. I could not locate an organic triple 20 fertilizer.  

Slow-Release Fertilizer  

Slow-release fertilizer consists of granules coated with a coating that gradually breaks down. As it breaks down, the nutrients in the fertilizer are released. Slow-release fertilizer usually takes seven days to see results and may last weeks or months between applications. I have not found a slow-release formulation of 20-20-20 fertilizer.  

When and How Do I Apply 20-20-20 Fertilizer?   

The exact amount of triple 20 fertilizer you apply depends on what you are fertilizing and the brand of fertilizer you are using. Always read and follow the label directions. That said, here are some typical ways to use triple 20 fertilizer by plant type, using the directions on the Southern Ag PowerPak 20-20-20 Water Soluble Fertilizer with micronutrients label.  


For indoor plants, I mix two teaspoons of fertilizer with a gallon of water. I drench the soil around the plant. Every two to three weeks, I use the fertilizer in place of water for my plants. I have found triple 20 to be too strong for many houseplants, particularly sensitive ones such as African violets.   

Alternatively, I mix two tablespoons of fertilizer with a gallon of water and spray it on my plant’s foliage. Foliar applications like this can perk up a plant that is hungry for the nutrients in the triple 20. Again, I have found that plants that are sensitive or do not like their foliage getting wet do not do well with triple 20 because it is too strong.  


Orchids can be fertilized with a 20-20-20 liquid fertilizer mixed at one-quarter strength. I would use ½ teaspoon of fertilizer with a gallon of water. Make sure the rooting media the orchids are growing in is damp before pouring fertilizer on it. Fertilize every week for three weeks out of the month. Once a month, flush the rooting media with water to remove any salt build-up. Do not use foliar applications of fertilizer for orchids. 

Annual Flowers  

As a foliar spray, I use five pounds per hundred gallons of water, which comes out to two tablespoons per gallon, to spray my annual plants every seven to ten days. I can also mix two teaspoons of triple 20 per gallon of water and drench the soil around the annuals every two to three weeks.  

Existing Ornamental Plants  

I treat my ornamental plants the same way I treat my annuals. However, I only apply triple 20 in the spring and then switch to a fertilizer with less nitrogen, so my plants do not grow too much foliage at the expense of the blooms.  

Bulbs and Tubers  

I don’t use triple 20 on bulbs and tubers when planting them. If they need fertilizer after the foliage has come up, I mix two teaspoons of triple 20 per gallon of water to use to water them once every two to three weeks. I do not use foliar applications with bulbs and tubers.  

Vegetable Gardens  

In new gardens with poor soil, I have applied a drench of triple 20 when I plant my seeds or transplants. I use two teaspoons per gallon of water. After the initial application, I switch to a fertilizer that has less nitrogen and is not as strong as triple 20. Triple 20 can be used in hydroponic systems to grow things like lettuce and other hydroponic vegetable crops. In hydroponic systems, 20-20-20 will work for tomatoes, but it has too much nitrogen for use on raised bed or in-ground tomatoes after the initial fertilization at transplant.

You can consult my article if you are looking for fertilizing your vegetable gardens.


When using triple 20 with trees, you need to mix enough to wet the entire area under the drip line. A foliar spray using five pounds of triple 20 to one hundred gallons of water is more practical and what I use. Be sure to wet all the leaves to the point they drip for good coverage.  


For 1,000 square feet of lawn, I apply one pound of triple 20 fertilizer with ten gallons of water. Repeat monthly or as needed. I use this to supplement my regular lawn fertilization program in poor soils, such as right after a new lawn is planted. I would not use it on an existing lawn as the only fertilizer as that would not be good for the lawn. Phosphorus and potassium can build up and cause problems.

Where Do I Buy 20-20-20 Fertilizer?   

Triple 20 fertilizer is available from Amazon or other online garden supply dealers. I have found it at big box stores like Walmart and Lowe’s, but not at Home Depot. Some nurseries have triple 20 fertilizers.  

Top Brands for 20-20-20 Fertilizers  

Here are some of the top brands of triple 20 fertilizers available. 

Jack’s/J.R. Peters, Inc. 

J.R. Peters, Inc. Has been in the fertilizer business since 1947. The company was started by Bob Peters in 1947 when he tested the soil in greenhouses and made fertilizer recommendations to improve their yield. He introduced Peters Professional Plant Food as the world’s first blue water-soluble fertilizer. The company still does soil testing for professionals, but also focuses on producing custom fertilizers for growers. In 1997, they introduced the Jack’s Classics line of fertilizers, which they believe are the finest fertilizers they have ever produced. In 2002, the company introduced the Jack’s Professional fertilizers, which are even better than the original Peters Professional Plant Food. 

Southern Agricultural Insecticides, Inc. 

Southern Ag was started in the 1930s by Hans Diem and produced pesticides for crop dusting by hand. The company was incorporated in 1947. The company is still owned by the founding family. Since 1947, Southern Ag has expanded the products it offers and produces pesticides, fertilizers, potting soils, and horticultural supplies in Florida and North Carolina and sells them worldwide. They produce products for both professionals and homeowners. 

EZ-gro/Plant Products 

EZ-gro is made by Plant Products, a member of Biobest Group. They are a distributor of fertilizers, synthetic and biological pesticides, Biobest® biological controls, substrates, seeds, and other products for specialist horticultural businesses. Plant Products combined with Biobest Group in February of 2022. Before that, Plant Products had served its customers for 75 years in Canada and the United States. Biobest is a company located in Belgium that specializes in biological pest control and is selling Plant Products’ line in Europe and around the world.  

My Recommendations for 20-20-20 Fertilizer  

Here are my top four 20-20-20 fertilizers.  

20-20-20 Liquid Fertilizer 

EZ-gro 20 20 20 Fertilizer – All Purpose Liquid Plant Food is my pick for the best liquid 20-20-20 fertilizer. This fertilizer is a concentrate and fertilizes a lot of plants per package. It contains some of the micronutrients and trace elements plants need, but not all of them. EZ-gro 20 20 20 Fertilizer – All Purpose Liquid Plant Food comes with a handy measuring cup so mixing it in water is easy. You don’t have to worry about putting the wrong amount of fertilizer in the water. It is not organic.  

EZ-gro 20 20 20 Fertilizer – All Purpose Liquid Plant Food has some, but not all, micronutrients. This concentrate is mixed using the measuring cup provided. I shake the container well, then mix seven ounces of fertilizer per gallon of water to drench around outdoor plants every seven to fourteen days. I mix 2/3 ounces of fertilizer per gallon of water and use it to water my indoor plants every time I water.   

20-20-20 Water Soluble Fertilizer Runner-Up   

Peters Professional 20-20-20 General Purpose Fertilizer is my pick for the runner-up to the best water-soluble fertilizer. I mention it because it is a famous triple 20 product. Peters plant foods have a long track record of taking care of indoor plants. This one also works for outdoor plants. This fertilizer can be used as a foliar spray or as a drench. Both start working immediately to feed your plants. Peters Professional 20-20-20 General Purpose Fertilizer has the most commonly needed micronutrients and trace elements. This fertilizer is a great general-purpose fertilizer. It is not organic.  

Peters Professional 20-20-20 General Purpose Fertilizer is intended for indoor and outdoor plants. Use one cup per twenty-five gallons of water outside on the roses and other ornamentals. Indoors, use one teaspoon per gallon of water for weekly feeding. I remember my father having a tub of Peter’s Plant Food when I was a kid for our potted plants.  The blue stains, so be careful not to get it on any clothing. 

20-20-20 Water Soluble Fertilizer 

Jack’s Classic All Purpose 20-20-20 Water Soluble Plant Food has micronutrients and trace elements in addition to nitrogen, phosphorous, and potassium. This fertilizer is made by the same company that makes Peters plant food but is an updated and improved triple 20 fertilizer. J.R. Peters said when it came out in 1997 that they believe that it is the best fertilizer they have ever made. Used indoors or out, Jack’s Classic All Purpose 20-20-20 Water Soluble Plant Food will make your plants grow well and look nice. This is not an organic fertilizer. It also is blue and stains, so watch what you get the fertilizer on. 

For outdoor plants, I mix one tablespoon per gallon of water and water my plants with it every seven to fourteen days. For indoor plants, I mix ½ teaspoon of fertilizer per gallon of water and use it to water my plants every two weeks. A measuring spoon is included in the fertilizer. 

20-20-20 Fertilizer – Best Overall  

Southern Ag PowerPak 20-20-20 Water Soluble Fertilizer with micronutrients is my pick for the best overall triple 20 fertilizer. It contains some micronutrients and trace elements plants need. Southern Ag fertilizer is easy to mix and dissolves quickly in water. This fertilizer can be used inside and out on practically everything that grows. Southern Ag triple 20 is not organic and does have artificial colors in it.  

Southern Ag PowerPak 20-20-20 Water Soluble Fertilizer with micronutrients has, as advertised, micronutrients that plants need to grow. It does not have all the micronutrients, however. This fertilizer can be applied as a foliar spray or as a drench. The instructions for doing either are listed under how to apply triple 20 above. 

What Are the Ingredients in Triple 20 Fertilizer?   

Each bag of triple 20 fertilizer is guaranteed to have twenty percent nitrogen, twenty percent phosphorous, and twenty percent potassium. Beyond that, some brands of triple 20 fertilizers have other nutrients that plants need. Different brands may have proprietary ingredients designed to help the plants use the nutrients better. Fillers to make it easier to spread the fertilizer and compounds to retard spoilage make up the balance of the ingredients.  

20-20-20 Versus 10-10-10

20-20-20 is twice as strong as 10-10-10. I have also only found liquid or water-soluble 20-20-20, but 10-10-10 is available in liquid, water-soluble, and granular form. While 10-10-10 is a good general fertilizer, 20-20-20 is too strong for many plants. The liquid and water-soluble versions of 20-20-20 can be difficult to handle when spraying lawns and tall trees. Triple 10 is available in slow-release form, while 20-20-20 is only available in fast-release versions. This means you have to fertilize more often with 20-20-20 than with granular forms of 10-10-10. In short, 10-10-10 will fertilize virtually everything, while 20-20-20 is more suited to potted plants, roses, and ornamentals.

Frequently Asked Questions  

How long does it take triple 20 to work?  

Most triple 20 fertilizers are liquids or are mixed into water. They are taken up by the plant’s roots immediately and start working. I have seen results as soon as twenty-four hours after fertilizing a plant.  

How long does triple 20 fertilizer last?   

Most triple 20 fertilizers last seven to fourteen days.  

Is 20-20-20 good fertilizer for fall?   

Triple 20 can be used on annuals until they die from frost. Ornamentals, shrubs, and trees should not be fertilized within four weeks of the average first frost date. Lawns can be fertilized in the fall, as can vegetables and indoor plants.  

Will 20-20-20 fertilizer kill weeds?  

No, triple 20 is a fertilizer, not a weed killer.  

Will 20-20-20 fertilizer burn grass?   

Triple 20 can burn grass if it is mixed too strongly or administered too often. Following the label directions will help keep your grass from burning.  

Will 20-20-20 fertilizer cure my sick plants?  

If your plants are sick because they lack nitrogen, phosphorous, or potassium, triple 20 fertilizer can help them. If your plants have a disease or pest problem, triple 20 fertilizer will not help them.  

Is 2-2-2 fertilizer the same as 20-20-20?  

No, they are not the same. Triple 20 has ten times the amount of fertilizer as 2-2-2.  

What is the difference between 20-20-20 and 14-14-14 fertilizer?  

Triple 20 fertilizer has twenty percent of nitrogen, phosphorous, and potassium, while triple 14 has only fourteen percent of nitrogen, phosphorous, and potassium.  

Are all 20-20-20 fertilizers the same?  

No. All triple 20 fertilizers have the same amount of nitrogen, phosphorous, and potassium. Different manufacturers include extra nutrients, proprietary ingredients to improve the fertilizer and different fillers.  

Can I make homemade 20-20-20 fertilizer?  

Yes, you can make homemade triple 20 fertilizer by combining sources of nitrogen, phosphorous, and potassium.  

In conclusion, triple 20 fertilizer can be used to add nutrients to the soil of a variety of plants. However, it is most often used on ornamentals and houseplants. Triple 20 primarily comes as water-soluble granules that are mixed with water and applied as a drench around the plant. Because it is in water, triple 20 has to be reapplied every seven to fourteen days. Some sensitive houseplants may find triple 20 too strong, so caution should be taken when using it to fertilize those plants. You can mix it at one-quarter strength to use it on orchids and other plants that get fertilizer burn easily. Many of these fertilizers contain a blue dye that stains anything it touches, so be very careful not to get it on concrete, wood, clothing, or rugs. 

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Stephanie Suesan Smith

Stephanie Suesan Smith has a Ph.D. in psychology that she mainly uses to train her dog. She has been a freelance writer since 1991. She has been writing for the web since 2010. Dr. Smith has been a master gardener since 2001 and writes extensively on gardening. She has advanced training in vegetables and entomology but learned to garden from her father. You can see her writing samples at https://gardencopywriter.com/garden-writing, and her vegetable blog at https://stephaniesuesansmith.com/.

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