0 20 20 Fertilizer: What It Is and Why You Need It (2024)

The most important thing for a gardener is to make sure their plants are healthy and thriving. Using the right kind of fertilizer can make a huge difference. I am going to talk about what 0-20-20 fertilizer is and why you need it. As most stores no longer stock this kind of fertilizer, I will also talk about how you can mix it up yourself. It’s easier than you think and could make a big difference in how well your plants thrive!

You want your plants to thrive and grow strong, so you must provide the proper nutrients for them. But what kind of fertilizer should you use and when? We’ll give you the inside scoop on 0-20-20 fertilizer. You’ll find out what it is and how much your plants will love it.

Unfortunately, most stores do not sell this type of fertilizer anymore. But don’t despair. Making your own 0-20-20 fertilizer is easier than you might think! You don’t even need any fancy equipment or ingredients. I’ll walk you through the process step by step so you can make your own at home.

In a Hurry?

Click on the table of contents below and jump directly to the section that interests you.

What is 0-20-20 fertilizer?

0-20-20 fertilizer contains 0% nitrogen, 20% potassium, 20% phosphorus and 60% filler. It is not available in stores, but you can make your own by mixing phosphorus, potassium, and a suitable filler.

Why Use 0-20-20 Fertilizer?

Fertilizers are used to increase the quantity and quality of nutrients in the soil. With a 0-20-20 fertilizer, you are boosting phosphorus and potassium levels, but not nitrogen. Why would we leave out the nitrogen??

Nitrogen is vital for the growth of plant leaves. Plants with a lack of nitrogen will not grow as much foliage as plants with plenty of nitrogen. Leafy plants, such as grass, require lots of nitrogen.

However, too much nitrogen can cause problems in your plants.

• It tends to produce plants with a lot of foliage and not so many flowers or crops. While this may be great for your grass, it is not suitable for flowers and food crops.
• Nitrogen fertilizers, particularly those at high dosages,appear to reduce vitamin C levels in various fruits and vegetables, including potatoes, tomatoes, and citrus fruits.

Low-nitrogen fertilizers push plants to focus on producing their fruits and flowers rather than their leaves. Too much of anything can be harmful, but excessive nitrogen in the soil is especially detrimental.

• Too much nitrogen in the soil can cause an imbalance in the soil’s nutrients. When this happens,the ph in your soil can start to rise. It also causes theloss of other soil nutrients such as calcium and potassium.
• Nitrogen is soluble. Rain or irrigation causes it to dissolve and leach into groundwater, waterways, and nearby wells. In January 2013, the California State Water Resources Control Board reported that more than 400 private wells and more than 200 water systems were contaminated with nitrates from fertilizers. These can cause amyriad of health problems.
• When nitrogen levels in waterways such as rivers, streams, and lakes increase, algae overgrowth. Some of these algae canproduce toxins that make people and animals sick. Algae overgrowth causes an imbalance in the water ecosystem.It may cause oxygen levels to drop or stop the sunlight from reaching plants at deeper levels. Both of these things can cause fish and other animals to die.

Read this scientific paper for an in-depth look at some of the consequences of altering the nitrogen cycle by fertilizers.

A Word About Soil Test Kits

This posts containsaffiliate links. This means we earn a commission from sales made via product links in this post.Read our full affiliate disclosure.

Asoil test kithelps you take a close look at the nutrient levels in your soil, as well as pH values. Once you know what is going on, you can choose what fertilizers and soil amendments you might need. It is a great way to determine the exact nitrogen levels in your soil.

But what do you do when you have the results?This handout from the University of Maine explains how to interpret the results. It also explains how to calculate the exact amount of nutrients needed to amend your particular soil.

This post deals specifically with a 0-20-20 fertilizer, but we recommend testing your soil as an excellent first step.

Where and Where to Use 0-20-20 fertilizer

Naturally, you can use 0-20-20 fertilizer if your soil test results show that you have sufficient nitrogen.

On flowering Plants

Otherwise, you can use it on flowering plants and crop plants that produce fruit. This would include fruit bushes and trees, of course. But it also benefits plants such as tomatoes, cucumbers, squash, and peppers.

On clover and legumes

The earth’s atmosphere is about 80 percent nitrogen, but unfortunately, plants cannot use it. Some species, such as clover and legumes (peas and beans), have developed a way to use that nitrogen. These plants have what is known as nitrogen-fixing bacteria (Rhizobium)in their roots. This bacteria converts the nitrogen from the air into a form the plant can use. These kinds of plants do not need additional nitrogen as they can make their own.

As a winterizing fertilizer

Zero nitrogen fertilizer can also be used as a winterizing fertilizer. As there isn’t much vegetative growth in winter, nitrogen isn’t required. It will be applied in the fall months leading up to winter.

While plants are dormant during the winter, they don’t require as much nitrogen as in the summer. Because it is so soluble, snow and rain may easily wash away any nitrogen that remains.

The need for nitrogen is almost nonexistent in winter. Most plants are dormant and vegetative growth is at a standstill. Snow and rain will just wash the nitrogen away.

Why spend money on something that will simply be wasted. Besides, as we have seen, nitrogen runoff can have an impact on our environment and health.

What Do You Need To Mix A 0-20-20 Fertilizer?

• Phosphorus
• Potassium
• Filler material
• Large storage container (with lid)
• Permanent marking pen
• Tarp
• Gardening gloves
• Shoes or gardening boots
• Measuring cups or kitchen scale

Filler will make up a large percentage of your final mix. They are used to decrease the concentration of Phosphorus and Potassium, which would burn the plant’s stems and roots if used undiluted. They also make it easier to spread the fertilizer. Suitable fillers include coarse sand, sterile dirt, peat moss, sawdust, or granular limestone.

I provided links for the essential ingredients; however, my advice would be to go to your local farmer’s supply store. They should have the elements you need in bulk and at better prices. A store that sells landscaping supplies should be able to provide you with the filler.

Doing the Math

Don’t panic! The math for mixing up a 0-20-20 fertilizer is not that hard.

Remember our formula is 0-20-20

• 0% nitrogen
• 20% Phosphorus
• 20% Potassium
• 60% filler

This means you need equal quantities of Phosphorus and Potassium and three times as much filler. Let’s do that in cups.

• 1 cup of Phosphorus
• 1 cup of Potassium
• 3 cups of filler

This will be five cups in all. So, if we did it in pounds, it would be 1 pound each of Phosphorus and Potassium and 3 pounds of filler. This would be five pounds in all.

How to Mix 0-20-20 fertilizer

The next step is mixing the fertilizer! If you have a concrete area in your garden, this is an ideal spot. However, I prefer to use a tarp as it keeps the chemicals contained.

On the tarp, place equal portions of the phosphorus and potassium fertilizers. Next, add in the right amount of filler material according to the formula as discussed earlier.

So, if you weigh out two pounds of phosphorus, you must add two pounds of potassium and six pounds of filler. Once all the ingredients are ready, use your shovel to mix everything thoroughly.

Safety first: Make sure you are wearing gloves and be sure not to breathe in any of the dust. You should be safe if you are mixing outside, but a mask will ensure that you don’t breathe in any chemicals. I would not mix with pets or children around.

How To Store The Fertilizer

Once the fertilizer is mixed, you need to store it. Keep it in a large plastic bucket with a lid. Label the container clearly with the name 0-20-20 fertilizer, so you are clear about what it is.

When storing 0-20-20 fertilizer, be sure it is placed in a dry spot. It needs to be kept out of reach of children and pets and away from other chemicals.

Looking For grass fertilizer? 0-20-20 fertilizer is not suitable for grass. You will want something with nitrogen in it. Check out our reviews of the best weed and feeds for grass.

Use 0-20-20 Fertilizer Correctly To Protect Your Plants.

Spread fertilizer into the soil at the start of the growing season. After that, apply a light side dressing of fertilizer around the growing plants. The 0-20-20 fertilizer can be applied anytime during the growing season, but do not apply it directly to the leaves or stems of plants. Instead, use a hoe or spade to work it into the soil around the plants.

All dry fertilizers should be worked or watered into the top three to five inches of soil. Finish by watering. This ensures the nutrients leach down into the roots where the plant needs them most, without burning the plant. If at all possible, try to apply the fertilizer when rain is forecast. The rain will help leach those nutrients down to roots as well.

Why You Don’t Find 0-20-20 Fertilizer in Stores

As time passed, stores quit stocking blends with zero nitrogen fertilizers because customers stopped buying them. I did some research to see if I could find out why. There seemed to be two reasons.

Firstly, many customers became focused on growing beautiful lawns, and they wanted fertilizers with nitrogen in the mix. Naturally, grass benefits significantly from a nitrogen-rich fertilizer. Promoting strong, vigorous leafy growth with a beautiful dark green color is what nitrogen does best.

Secondly, companies started producing organic fertilizers containing time-release granules that dissolve slowly and release their nitrogen gradually over time. This is the perfect solution for busy gardeners who are looking to cut down on garden chores.

Still, as we have seen, there is a time and a place for 0-20-20

What Do The Numbers on Fertilizer Bag Mean?

The three figures listed on fertilizers represent the percentage of nitrogen (N), phosphorus (P), and potassium (K) in the product.

These are the three primary nutrients needed by plants. The remainder of the fertilizer mix is made up of filler materials to make for easy spreading.

In brief,

• Nitrogen stimulates the growth of leaves and stems
• Phosphorus promotes the growth of flowers and fruit. It also plays a vital role in root development.
• Potassium also helps with root development, cell strengthening, disease resistance, and overall plant health.

Final Thoughts

This post is all about 0-20-20 fertilizer. We have shown you how to make your own, and why it has a special place in the garden. It is no longer available in stores, but it is easy to mix up yourself! We hope you’ve found this article to be interesting and informative. Please share this article with other gardeners who might be looking for help! Thanks for reading!