How Long Does Soil Acidifier Take to Work?

Understanding exactly what soil acidity is and how it relates to a plant’s health is very complex but also very important. For information on soil acidity and how it relates to plant growth, you can read more here: 5 Reasons Why Soil PH is So Important. However, you may still be wondering how long it will take for a soil acidifier to take effect.

Soil acidifiers take between six months and one year to actually change soil pH levels. Put simply, a soil acidifier engages in a chemical reaction with particles already in the soil, thus changing acidity. If the soil acidifier is used evenly over a patch of land, it will take equal time to work.

Using a soil acidifier is a great way to change the pH of your soil, but the way it works is somewhat complex. Read on to learn more about what soil acidifier is, how it works, and why you might want to make your soil more acidic. I’ll also discuss some troubleshooting information for using soil acidifiers.

Understanding Soil Acidifier and Its Purpose

When you think about soil acidifiers at an abstract level, it might not seem all that confusing or too difficult to understand. Without knowing much about pH and acidity, you might know that the two basic components of the acidity scale are acids and bases

You might have heard of popular acids like sulfuric acid or hydrochloric acid (the acid in your stomach). So, is applying soil acidifier the same as just pouring acid over the ground?

While that isn’t exactly how it works, you aren’t too far off. Soil acidifier is an additive that can be added to your soil in order to lower the pH of the soil, thus raising the acidity of the soil. Similar in appearance to fertilizer, soil acidifiers are an eco-friendly way of raising your soil’s acidity. Most soil acidifiers are made from natural ingredients, making them ideal for almost all soil types.

You might be asking, why can’t I just pour an acidic substance into my soil and call it a day? The reason is two-fold. First, adding just a random acidic substance won’t necessarily change your pH in the long term. While it might work temporarily, it will soon dissipate as it is exposed to the elements. It also can’t be applied evenly, so you would be left with patches of acidic soil.

The second reason that this shouldn’t be done is that it is ecologically unfriendly. Soil relies on many bacteria and microorganisms to break down organic matter into nutrients. By adding acid at random to the soil, you could easily kill these bacteria and microorganisms, reducing the soil’s quality.

How Soil Acidifier Works

Now that you understand what soil acidifier is, you are likely wondering how soil acidifier works. In order to explain this, it is best to understand how pH can change through a chemical reaction. pH, the measure of acidity, is simply a measurement of hydrogen ions in a solution. These are generally water-based solutions, also known as aqueous solutions.

In short, particles—and even some compounds—have a very slight electric charge to them. Oxygen, for example, has a very slight negative charge due to the compound having one extra electron. 

Compounds and atoms don’t like to be charged in any way, however. Instead, they like to bind with other particles to try and achieve a natural charge. For this reason, Oxygen easily binds with two Hydrogen particles, which have a slight positive charge. When combined, these two particles achieve no charge, also known as neutrality. It also makes, in this instance, H2O (water).

When it comes to pH (which literally means potential hydrogen), those particles or compounds that have an extra hydrogen ion and are capable of “donating” their extra charge are acids. A base is a particle or compound receiving the donation, meaning they are willing to accept the hydrogen ion. Bases have a high pH, while acids have a low pH.

So, how does this work with soil acidifiers? Most soil acidifiers introduce sulfur to the soil. When combined with the oxygen and water in the soil, sulfur undergoes a hydrogen ion-sharing circumstance in which it becomes acidic. This means that, in introducing more sulfur, the soil acidifier is just making a chemical reaction in which more particles and compounds are ready to “donate” their extra charge.

Benefits of Using Soil Acidifiers

Now that we understand what soil acidifiers are and how they work, the next logical step is to ask why exactly you might want to make your soil more acidic. If acids are used to break down the nutrients in your stomach and can kill microorganisms and bacteria that help make your soil great for plant life, why would you want them in your soil?

While it may be surprising to some people, certain plants actually rely on having soil that is more acidic. While most plants prefer soil that is relatively neutral (meaning slightly more or less acidic than water), there are some plants that thrive in acidic soil. This is largely for two reasons. Firstly, certain plants need more of the nutrients that make the soil acidic.

Many legumes, for example, rely heavily on sulfur. While it could be that these plants tend to utilize sulfur that is not acidic, most traces of sulfur underground actually come in the form of some level of sulfuric acid. This shows that while the plants don’t necessarily need the soil to be acidic in order to thrive, they do need the nutrients that many acids provide.

The second major reason some plants prefer acidic soil is because they rely on the chemical nutrients that the acids help to produce. When certain bacteria and fungi are exposed to acids, they release chemicals such as ammonia. Blueberries love ammonia as a source of nutrients, thus they rely on acidic soil.

If you want to grow plants that prefer acidic soil, then (unless the soil you are using is already slightly acidic) you can use a soil acidifier to help the plants thrive.

Troubleshooting Usage of Soil Acidifiers

While science is predictable to a point, there is always some variability in the effects that a certain action will cause. While we might be able to add soil acidifiers to our soil, this doesn’t necessarily mean that we are going to reach the exact level of acidity that we want every time. Nature is not a controlled environment—there will always be variability.

Soil Composition Affects Soil Acidifier Effectiveness

So, what happens if after applying a soil acidifier and waiting six months for the effects to kick in, the soil’s pH is largely unchanged? This could be due to the composition of the soil. Soils that do not drain as well often are not able to acidify quite as well.

If your soil is made of clay or silt, this might explain why the acidification process is taking longer. Try to change the composition of your soil by adding more dirt or peat.

Soil That Is Too Compressed Resists Change in Acidity

Another reason that your soil might not be becoming more acidic is that it is too compressed. Loose soil with organic compounds in it is best prepared to change its acidity level. If your soil is very compact and is not becoming more acidic, try to rototill or stiff up the soil in another way.

Take Care Not to Overuse Soil Acidifiers

While certain plants need acidity to survive, it is possible to introduce too much acidity into the soil. 

So, what happens if your soil becomes too acidic? Sometimes, you might add too much acidifier so that the soil is too acidic to grow vegetation. If this is the case, try adding some sort of acid neutralizer such as limestone to help lower the acidity. 

If you would like to learn more about how often you should use soil acidifier, check out my article: How Often Should You Use Soil Acidifier?

Final Thoughts

When it comes to making your soil more acidic, soil acidifiers are a quick and easy way to lower pH and increase acidity. Soil acidifiers typically take between 6 months and a year to take effect. Soil acidifiers work by adding sulfur to the soil which decreases the pH level.

While soil acidifiers are often an effective way of changing soil pH, they do not always work. Try troubleshooting your soil with the steps above and if all else fails, contact a professional for help.

If you are interested in making your soil more acidic naturally, you could check out this article: 5 Natural Ways to Make Soil More Acidic

Alexander Picot

Alexander Picot is the principal creator of, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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